1 00:00:06,309 --> 00:00:04,870 hello and welcome to the space telescope 2 00:00:08,230 --> 00:00:06,319 public lecture series 3 00:00:10,709 --> 00:00:08,240 i'm your host dr frank summers of the 4 00:00:13,669 --> 00:00:10,719 space telescope science institute 5 00:00:15,749 --> 00:00:13,679 tonight's talk shaping galaxies with 6 00:00:19,429 --> 00:00:15,759 supermassive black hole wins 7 00:00:25,189 --> 00:00:22,710 i want to thank our amazing tech team 8 00:00:26,150 --> 00:00:25,199 thomas marufu and grant justice they 9 00:00:28,470 --> 00:00:26,160 have been helping us 10 00:00:29,589 --> 00:00:28,480 transform from our live audience in the 11 00:00:32,709 --> 00:00:29,599 auditorium 12 00:00:34,470 --> 00:00:32,719 to our online only and i will say that 13 00:00:35,510 --> 00:00:34,480 our lecture series will continue to be 14 00:00:40,470 --> 00:00:35,520 online only 15 00:00:44,310 --> 00:00:42,869 next month we have a special date it 16 00:00:46,950 --> 00:00:44,320 will be on january 17 00:00:48,869 --> 00:00:46,960 19th we're skipping the first one first 18 00:00:50,470 --> 00:00:48,879 tuesday because it's around new year's 19 00:00:52,950 --> 00:00:50,480 we're skipping the second tuesday 20 00:00:54,150 --> 00:00:52,960 because it's the american astronomical 21 00:00:56,709 --> 00:00:54,160 society meeting 22 00:00:59,270 --> 00:00:56,719 and we're going to the third tuesday 23 00:01:00,150 --> 00:00:59,280 january 19th in which we have an amazing 24 00:01:03,110 --> 00:01:00,160 talk for you 25 00:01:04,549 --> 00:01:03,120 the darkest secrets of the universe from 26 00:01:07,350 --> 00:01:04,559 rajya muhat the curta 27 00:01:07,910 --> 00:01:07,360 from university of santa cruz this is 28 00:01:10,550 --> 00:01:07,920 one 29 00:01:11,670 --> 00:01:10,560 you're really gonna enjoy this i know in 30 00:01:14,390 --> 00:01:11,680 february and 31 00:01:15,830 --> 00:01:14,400 in march we will both be meeting on the 32 00:01:18,950 --> 00:01:15,840 second of the month 33 00:01:21,190 --> 00:01:18,960 and because we were quite sure how long 34 00:01:22,789 --> 00:01:21,200 all this coronavirus stuff would last we 35 00:01:25,030 --> 00:01:22,799 hadn't scheduled yet 36 00:01:26,469 --> 00:01:25,040 but it's now time to start scheduling 37 00:01:29,030 --> 00:01:26,479 all throughout 2021 38 00:01:30,390 --> 00:01:29,040 so don't worry as always i will make 39 00:01:33,109 --> 00:01:30,400 sure we have speakers 40 00:01:34,950 --> 00:01:33,119 in february and march where can you find 41 00:01:38,230 --> 00:01:34,960 out that information when it pops up 42 00:01:41,429 --> 00:01:38,240 well of course you can go to our website 43 00:01:44,389 --> 00:01:41,439 this if you just go to sdsci.edu 44 00:01:46,630 --> 00:01:44,399 public hyphen lectures you will find 45 00:01:49,990 --> 00:01:46,640 this webpage talking about it 46 00:01:53,429 --> 00:01:50,000 um you can see in the lower left 47 00:01:56,630 --> 00:01:53,439 there is the um links to our webcast 48 00:01:58,870 --> 00:01:56,640 both our youtube playlist as well as our 49 00:01:59,670 --> 00:01:58,880 webcast archive on the space telescope 50 00:02:01,910 --> 00:01:59,680 site 51 00:02:03,670 --> 00:02:01,920 um and in the lower right you can see 52 00:02:05,670 --> 00:02:03,680 how you can subscribe to our 53 00:02:08,389 --> 00:02:05,680 announcements and get an email 54 00:02:09,910 --> 00:02:08,399 once or twice a month about the public 55 00:02:12,309 --> 00:02:09,920 lectures 56 00:02:13,030 --> 00:02:12,319 also on the website are the links to the 57 00:02:15,190 --> 00:02:13,040 individual 58 00:02:17,589 --> 00:02:15,200 lectures and if you click on one of 59 00:02:19,830 --> 00:02:17,599 those lectures you get the full detail 60 00:02:21,190 --> 00:02:19,840 about it after it's been recorded you 61 00:02:24,229 --> 00:02:21,200 can view the webcast 62 00:02:26,070 --> 00:02:24,239 on the stsci webcast site or down bottom 63 00:02:27,510 --> 00:02:26,080 on the youtube site and get all the 64 00:02:32,790 --> 00:02:27,520 information about the speaker 65 00:02:35,110 --> 00:02:32,800 and the um and the abstract 66 00:02:36,710 --> 00:02:35,120 for email well the announcements you can 67 00:02:37,910 --> 00:02:36,720 just sign up at the website as i showed 68 00:02:40,710 --> 00:02:37,920 you previously 69 00:02:41,350 --> 00:02:40,720 you can also subscribe to our youtube 70 00:02:44,630 --> 00:02:41,360 channel 71 00:02:45,990 --> 00:02:44,640 uh youtube.com hubble space telescope 72 00:02:48,150 --> 00:02:46,000 all one word 73 00:02:49,430 --> 00:02:48,160 uh if you do subscribe to our youtube 74 00:02:51,750 --> 00:02:49,440 channel you'll get 75 00:02:54,470 --> 00:02:51,760 new notices of new videos as well as 76 00:02:56,070 --> 00:02:54,480 reminders of these live events 77 00:02:57,910 --> 00:02:56,080 finally if you have comments or 78 00:02:58,630 --> 00:02:57,920 questions you can send them to public 79 00:03:02,390 --> 00:02:58,640 lecture 80 00:03:05,190 --> 00:03:02,400 at stsci.edu 81 00:03:06,550 --> 00:03:05,200 on social media we do social media for 82 00:03:08,309 --> 00:03:06,560 the hubble space telescope 83 00:03:10,550 --> 00:03:08,319 for the upcoming james webb space 84 00:03:11,750 --> 00:03:10,560 telescope and for the space telescope 85 00:03:14,710 --> 00:03:11,760 science institute 86 00:03:16,229 --> 00:03:14,720 and those platf those institutions are 87 00:03:19,350 --> 00:03:16,239 represented on facebook 88 00:03:21,270 --> 00:03:19,360 twitter youtube and instagram so 89 00:03:22,790 --> 00:03:21,280 a whole lot of social media uh 90 00:03:26,309 --> 00:03:22,800 presentation for you 91 00:03:28,229 --> 00:03:26,319 myself i do a tiny tiny bit on facebook 92 00:03:31,990 --> 00:03:28,239 and twitter if you want to follow me 93 00:03:34,550 --> 00:03:32,000 please do so and now 94 00:03:37,509 --> 00:03:34,560 the news from the universe for december 95 00:03:46,710 --> 00:03:40,869 our first story tonight the fading glory 96 00:03:51,149 --> 00:03:46,720 of supernova 2018 gv 97 00:03:54,309 --> 00:03:51,159 this is the this is the galaxy ngc 98 00:03:55,670 --> 00:03:54,319 2525 and as you can see it's a nice 99 00:03:58,070 --> 00:03:55,680 spiral galaxy 100 00:04:00,070 --> 00:03:58,080 this is a ground-based observation from 101 00:04:01,509 --> 00:04:00,080 uh the carnegie observatory 102 00:04:03,350 --> 00:04:01,519 and you can see that's got some 103 00:04:04,390 --> 00:04:03,360 interesting spiral structure and 104 00:04:07,830 --> 00:04:04,400 everything 105 00:04:12,309 --> 00:04:07,840 but ground-based doesn't quite capture 106 00:04:15,509 --> 00:04:12,319 the real detail in there this 107 00:04:17,509 --> 00:04:15,519 that's the hubble image yeah isn't that 108 00:04:19,349 --> 00:04:17,519 amazing that you get the resolution 109 00:04:21,030 --> 00:04:19,359 by getting up above earth's atmosphere 110 00:04:21,830 --> 00:04:21,040 you get an amazing resolution let me go 111 00:04:24,870 --> 00:04:21,840 back 112 00:04:28,150 --> 00:04:24,880 here is ground-based and here is 113 00:04:30,790 --> 00:04:28,160 hubble ah yeah kind of great 114 00:04:31,909 --> 00:04:30,800 but there's also one thing kind of 115 00:04:33,270 --> 00:04:31,919 interesting 116 00:04:34,550 --> 00:04:33,280 i don't know if you guys saw it watch 117 00:04:35,670 --> 00:04:34,560 carefully all right we'll go back to the 118 00:04:37,749 --> 00:04:35,680 ground based 119 00:04:39,189 --> 00:04:37,759 now see if you can see something pop on 120 00:04:42,550 --> 00:04:39,199 when we go to the 121 00:04:45,909 --> 00:04:42,560 hubble to catch it it's 122 00:04:49,990 --> 00:04:45,919 right up here that is not 123 00:04:53,909 --> 00:04:50,000 a star that is an exploded star 124 00:04:56,310 --> 00:04:53,919 supernova 2018 gv 125 00:04:56,950 --> 00:04:56,320 now it looks like a star but really it's 126 00:04:58,629 --> 00:04:56,960 it's not 127 00:05:01,029 --> 00:04:58,639 it's a supernova explosion which is 128 00:05:02,310 --> 00:05:01,039 extremely bright all the other stars you 129 00:05:05,350 --> 00:05:02,320 see in this image 130 00:05:07,990 --> 00:05:05,360 they're not in the galaxy ngc 2525 131 00:05:09,749 --> 00:05:08,000 they're in our own milky way galaxy 132 00:05:11,110 --> 00:05:09,759 remember as we look out through our 133 00:05:13,670 --> 00:05:11,120 milky way galaxy at 134 00:05:15,029 --> 00:05:13,680 distant galaxies beyond we have we go 135 00:05:16,950 --> 00:05:15,039 through this screen of stars so the 136 00:05:19,189 --> 00:05:16,960 stars you're seeing in this image 137 00:05:21,189 --> 00:05:19,199 are actually very close to us they're 138 00:05:24,550 --> 00:05:21,199 inside the milky way 139 00:05:29,270 --> 00:05:24,560 whereas 2018 gv is 140 00:05:32,550 --> 00:05:29,280 actually located in ngc 2525 141 00:05:34,070 --> 00:05:32,560 millions of light years away it has to 142 00:05:37,270 --> 00:05:34,080 be incredibly 143 00:05:39,270 --> 00:05:37,280 bright so that we can see it that far 144 00:05:41,430 --> 00:05:39,280 across the universe and that's one of 145 00:05:44,310 --> 00:05:41,440 the important things about supernovae 146 00:05:45,510 --> 00:05:44,320 is that we can see them occur in other 147 00:05:48,310 --> 00:05:45,520 galaxies 148 00:05:50,310 --> 00:05:48,320 and so this one was was first observed 149 00:05:51,510 --> 00:05:50,320 with a ground-based telescope in january 150 00:05:53,909 --> 00:05:51,520 2018 151 00:05:56,150 --> 00:05:53,919 and hubble started following in in 152 00:05:59,670 --> 00:05:56,160 february of 2018 153 00:06:00,950 --> 00:05:59,680 and hubble was able to watch as it faded 154 00:06:04,230 --> 00:06:00,960 away 155 00:06:07,510 --> 00:06:04,240 so this is a a close-up of 156 00:06:08,790 --> 00:06:07,520 a supernova 2018 starting in about 157 00:06:12,309 --> 00:06:08,800 february 2000 uh 158 00:06:13,189 --> 00:06:12,319 2018 going for about one year and it's a 159 00:06:14,629 --> 00:06:13,199 movie 160 00:06:17,590 --> 00:06:14,639 so we're gonna play it through and you 161 00:06:19,189 --> 00:06:17,600 can watch the star fade away 162 00:06:20,790 --> 00:06:19,199 and go back and looking it's like a 163 00:06:21,350 --> 00:06:20,800 small one this is only over a course of 164 00:06:23,350 --> 00:06:21,360 a year 165 00:06:25,590 --> 00:06:23,360 supernova actually fade over the course 166 00:06:27,350 --> 00:06:25,600 of about three or four years 167 00:06:29,110 --> 00:06:27,360 at least for uh for astronomers to 168 00:06:31,029 --> 00:06:29,120 follow them and you can watch and you 169 00:06:34,390 --> 00:06:31,039 can see we plotted a graph 170 00:06:37,510 --> 00:06:34,400 to show you the brightness um at peak 171 00:06:38,550 --> 00:06:37,520 and then following and fading down over 172 00:06:40,950 --> 00:06:38,560 time 173 00:06:42,550 --> 00:06:40,960 that's actually kind of important 174 00:06:45,749 --> 00:06:42,560 because 175 00:06:46,390 --> 00:06:45,759 the way a supernova decreases in its 176 00:06:49,670 --> 00:06:46,400 light curve 177 00:06:52,309 --> 00:06:49,680 from its peak magnitude down uh 178 00:06:53,430 --> 00:06:52,319 as it fades away actually tells us a lot 179 00:06:55,510 --> 00:06:53,440 about the physics 180 00:06:58,070 --> 00:06:55,520 of the supernova there are different 181 00:07:01,270 --> 00:06:58,080 types type 1a type 1b 182 00:07:03,189 --> 00:07:01,280 type 2b type 2 n i've never heard 183 00:07:05,110 --> 00:07:03,199 i hadn't heard of that until i looked at 184 00:07:06,950 --> 00:07:05,120 this chart earlier today 185 00:07:08,710 --> 00:07:06,960 um that's the hypernova stuff and you 186 00:07:10,870 --> 00:07:08,720 can see how there are various 187 00:07:12,790 --> 00:07:10,880 ways of involved that tells you and 188 00:07:16,309 --> 00:07:12,800 there are certain supernovae 189 00:07:19,990 --> 00:07:16,319 that are really important for cosmology 190 00:07:21,990 --> 00:07:20,000 these are the the type 1a supernovae 191 00:07:24,790 --> 00:07:22,000 and here are two others that occurred in 192 00:07:28,390 --> 00:07:24,800 other galaxies supernova 1994 d 193 00:07:31,430 --> 00:07:28,400 and supernova 2011 fe 194 00:07:33,430 --> 00:07:31,440 and by looking at these supernovae and 195 00:07:35,029 --> 00:07:33,440 finding out how they how how they 196 00:07:36,710 --> 00:07:35,039 decrease and 197 00:07:38,070 --> 00:07:36,720 understanding that gives us their 198 00:07:39,830 --> 00:07:38,080 maximum brightness 199 00:07:41,749 --> 00:07:39,840 which gives us distances to these 200 00:07:43,430 --> 00:07:41,759 galaxies which when we measure the 201 00:07:46,550 --> 00:07:43,440 redshifts of these galaxies 202 00:07:47,510 --> 00:07:46,560 helps us refine the expansion rate of 203 00:07:49,430 --> 00:07:47,520 the universe 204 00:07:50,790 --> 00:07:49,440 right this is actually part of a large 205 00:07:53,909 --> 00:07:50,800 project called 206 00:07:54,390 --> 00:07:53,919 shoes which is some convoluted acronym 207 00:07:56,150 --> 00:07:54,400 about 208 00:07:58,150 --> 00:07:56,160 supernova with hubble to measure the 209 00:08:00,309 --> 00:07:58,160 expansion rate of the universe all right 210 00:08:01,670 --> 00:08:00,319 and so it's a very large project 211 00:08:03,749 --> 00:08:01,680 looking for these different distant 212 00:08:06,469 --> 00:08:03,759 supernovae in these distant 213 00:08:07,189 --> 00:08:06,479 galaxies to measure the distances and 214 00:08:09,589 --> 00:08:07,199 the redshifts 215 00:08:10,629 --> 00:08:09,599 and measure the expansion rate of the 216 00:08:13,350 --> 00:08:10,639 universe 217 00:08:14,309 --> 00:08:13,360 so this is just one more piece in that 218 00:08:16,070 --> 00:08:14,319 puzzle 219 00:08:17,990 --> 00:08:16,080 but it's very nice that hubble was able 220 00:08:18,950 --> 00:08:18,000 to observe it many times over the course 221 00:08:22,469 --> 00:08:18,960 of a year 222 00:08:25,990 --> 00:08:22,479 to truly watch and see the fading glory 223 00:08:29,270 --> 00:08:26,000 of that supernova 224 00:08:33,670 --> 00:08:29,280 our second story arecibo over 225 00:08:36,949 --> 00:08:33,680 and out this is a sad story to tell 226 00:08:38,709 --> 00:08:36,959 because it's about the arecibo radio 227 00:08:40,949 --> 00:08:38,719 observatory which is located 228 00:08:42,550 --> 00:08:40,959 as you might guess in arecibo puerto 229 00:08:45,269 --> 00:08:42,560 rico 230 00:08:46,230 --> 00:08:45,279 arecibo is located in the mountains of 231 00:08:48,949 --> 00:08:46,240 puerto rico 232 00:08:50,470 --> 00:08:48,959 in a natural sinkhole and using the 233 00:08:52,630 --> 00:08:50,480 natural sinkhole which 234 00:08:54,870 --> 00:08:52,640 already does most of the shaping for it 235 00:08:58,710 --> 00:08:54,880 they were able to create a radio dish 236 00:09:00,790 --> 00:08:58,720 one thousand feet across uh it was built 237 00:09:03,030 --> 00:09:00,800 in the 1960s it started operation in 238 00:09:06,070 --> 00:09:03,040 november 1963. 239 00:09:08,550 --> 00:09:06,080 um so it is the has been the 240 00:09:09,670 --> 00:09:08,560 largest rate single dish radio 241 00:09:13,269 --> 00:09:09,680 observatory 242 00:09:13,990 --> 00:09:13,279 until 2016. for over 50 years it was the 243 00:09:17,430 --> 00:09:14,000 largest 244 00:09:19,269 --> 00:09:17,440 single aperture radio telescope 245 00:09:20,949 --> 00:09:19,279 it's been used for radio astronomy it's 246 00:09:22,710 --> 00:09:20,959 been used for radar astronomy 247 00:09:24,310 --> 00:09:22,720 they can actually send out signals with 248 00:09:26,470 --> 00:09:24,320 it um they 249 00:09:28,310 --> 00:09:26,480 have been used for atmospheric science 250 00:09:30,310 --> 00:09:28,320 um and it's also been used for the 251 00:09:33,269 --> 00:09:30,320 search for extraterrestrial intelligence 252 00:09:33,750 --> 00:09:33,279 they actually sent out a signal um out 253 00:09:36,470 --> 00:09:33,760 that 254 00:09:37,430 --> 00:09:36,480 maybe somebody somewhere will actually 255 00:09:41,110 --> 00:09:37,440 see 256 00:09:44,790 --> 00:09:41,120 extra 257 00:09:47,670 --> 00:09:44,800 in the movie contact 258 00:09:50,230 --> 00:09:47,680 starring jody foster that movie came out 259 00:09:53,110 --> 00:09:50,240 in 1997. 260 00:09:55,670 --> 00:09:53,120 of course that's sort of a geeky movie 261 00:09:57,990 --> 00:09:55,680 it was based on a book by carl sagan 262 00:09:59,509 --> 00:09:58,000 i'm sure most people remember the 263 00:10:01,990 --> 00:09:59,519 receiver radio observatory 264 00:10:03,670 --> 00:10:02,000 for its appearance in the james bond 265 00:10:06,069 --> 00:10:03,680 film goldeneye 266 00:10:08,150 --> 00:10:06,079 where pierce brosnan and sean bean had 267 00:10:11,350 --> 00:10:08,160 this big fight out on the radio 268 00:10:14,389 --> 00:10:11,360 uh array in the center of the dish okay 269 00:10:17,750 --> 00:10:14,399 uh yeah that never actually happened 270 00:10:20,230 --> 00:10:17,760 but you know people uh uh 271 00:10:23,110 --> 00:10:20,240 they actually filmed it while uh arecibo 272 00:10:25,750 --> 00:10:23,120 was under undergoing um 273 00:10:27,110 --> 00:10:25,760 uh undergoing repairs but the scene that 274 00:10:28,550 --> 00:10:27,120 they filmed was actually filmed with 275 00:10:29,829 --> 00:10:28,560 green screen around it so they didn't 276 00:10:30,389 --> 00:10:29,839 actually get out there in front of they 277 00:10:33,069 --> 00:10:30,399 did 278 00:10:34,630 --> 00:10:33,079 various scenes all right so 279 00:10:37,750 --> 00:10:34,640 unfortunately 280 00:10:40,949 --> 00:10:37,760 not even james bond can save the arecibo 281 00:10:43,670 --> 00:10:40,959 observatory from the ravages of time 282 00:10:43,990 --> 00:10:43,680 and this year has been particularly bad 283 00:10:45,910 --> 00:10:44,000 uh 284 00:10:47,829 --> 00:10:45,920 in august of this year one of the 285 00:10:48,790 --> 00:10:47,839 auxiliary cables you see this structure 286 00:10:51,190 --> 00:10:48,800 that's holding up 287 00:10:52,150 --> 00:10:51,200 uh the main radio platform uh receiver 288 00:10:54,870 --> 00:10:52,160 platform 289 00:10:55,269 --> 00:10:54,880 um one of the auxiliary cables snapped 290 00:11:04,790 --> 00:10:55,279 in 291 00:11:05,990 --> 00:11:04,800 uh and then you know they did the 292 00:11:07,670 --> 00:11:06,000 analysis and they said okay the 293 00:11:08,389 --> 00:11:07,680 remaining cable should be able to hold 294 00:11:11,509 --> 00:11:08,399 it 295 00:11:12,310 --> 00:11:11,519 but in on november 6th of this year one 296 00:11:13,990 --> 00:11:12,320 of the main 297 00:11:16,470 --> 00:11:14,000 cables not an auxiliary cable one of the 298 00:11:18,550 --> 00:11:16,480 main cables snapped 299 00:11:20,150 --> 00:11:18,560 and there was a significant damage which 300 00:11:22,949 --> 00:11:20,160 you can see in this big picture 301 00:11:26,069 --> 00:11:22,959 but let me bring up a close-up and you 302 00:11:28,790 --> 00:11:26,079 can see the kind of damage that was done 303 00:11:29,829 --> 00:11:28,800 and in mid-november around november 19th 304 00:11:31,670 --> 00:11:29,839 i think it was 305 00:11:33,269 --> 00:11:31,680 the national science foundation which 306 00:11:34,470 --> 00:11:33,279 runs this observatory 307 00:11:36,470 --> 00:11:34,480 announced that it would be dis 308 00:11:38,470 --> 00:11:36,480 decommissioned that they would not 309 00:11:39,910 --> 00:11:38,480 um be able to repair it it would cost 310 00:11:40,389 --> 00:11:39,920 too much they didn't have the budget for 311 00:11:43,590 --> 00:11:40,399 it 312 00:11:46,630 --> 00:11:43,600 um and that the world's one of these 313 00:11:47,910 --> 00:11:46,640 iconic telescopes uh would be would be 314 00:11:51,590 --> 00:11:47,920 mothball 315 00:11:53,990 --> 00:11:51,600 um however it still kept 316 00:11:55,190 --> 00:11:54,000 things still kept happening over the 317 00:11:58,069 --> 00:11:55,200 weekend 318 00:11:58,470 --> 00:11:58,079 several wires within cables snapped and 319 00:12:02,629 --> 00:11:58,480 around 320 00:12:03,750 --> 00:12:02,639 8 am this morning there was catastrophic 321 00:12:06,870 --> 00:12:03,760 failure 322 00:12:12,389 --> 00:12:06,880 the whole main 323 00:12:16,310 --> 00:12:12,399 array fell into the dish uh 900 tons 324 00:12:20,310 --> 00:12:16,320 of receiver platform fell over 400 feet 325 00:12:22,870 --> 00:12:20,320 down and smashed into the radio dish 326 00:12:24,629 --> 00:12:22,880 the news of this spread like a wildfire 327 00:12:25,350 --> 00:12:24,639 across the astronomical community this 328 00:12:27,110 --> 00:12:25,360 morning 329 00:12:28,710 --> 00:12:27,120 and i finally found this observe this 330 00:12:33,269 --> 00:12:28,720 image from um 331 00:12:37,030 --> 00:12:33,279 the science magazine and it's just 332 00:12:40,069 --> 00:12:37,040 yeah it's uh 57 years of this telescope 333 00:12:43,509 --> 00:12:40,079 it's in dirt hurricanes and earthquakes 334 00:12:46,470 --> 00:12:43,519 and unfortunately that is it 335 00:12:48,150 --> 00:12:46,480 so i will always remember the arab civil 336 00:12:50,230 --> 00:12:48,160 observatory like this 337 00:12:52,069 --> 00:12:50,240 uh in its heyday while it was producing 338 00:12:56,629 --> 00:12:52,079 amazing science across 339 00:12:59,509 --> 00:12:56,639 many fields started in 1963 340 00:13:01,670 --> 00:12:59,519 decommissioned in 2020 the arecibo 341 00:13:03,269 --> 00:13:01,680 observatory has had its last radio 342 00:13:08,710 --> 00:13:03,279 transmission 343 00:13:13,509 --> 00:13:11,990 and now to our featured speaker 344 00:13:16,629 --> 00:13:13,519 our featured speaker is mitchell 345 00:13:18,790 --> 00:13:16,639 robolsky and he has been with the space 346 00:13:20,710 --> 00:13:18,800 telescope science institute 347 00:13:22,470 --> 00:13:20,720 for about a year a little longer than a 348 00:13:24,389 --> 00:13:22,480 year uh he is a 349 00:13:25,829 --> 00:13:24,399 post-doc which is what you do after 350 00:13:26,949 --> 00:13:25,839 you've finished your graduate work you 351 00:13:29,190 --> 00:13:26,959 get your phd 352 00:13:31,110 --> 00:13:29,200 and then you do some post-docking before 353 00:13:33,910 --> 00:13:31,120 you then get your faculty job 354 00:13:35,670 --> 00:13:33,920 so uh this is actually probably the most 355 00:13:36,790 --> 00:13:35,680 productive time of your career where 356 00:13:39,430 --> 00:13:36,800 you're able to sit there 357 00:13:41,750 --> 00:13:39,440 really do your research right he got his 358 00:13:44,470 --> 00:13:41,760 phd at georgia state 359 00:13:46,150 --> 00:13:44,480 and his undergraduate work at the uh did 360 00:13:49,030 --> 00:13:46,160 his undergraduate work at the college of 361 00:13:49,990 --> 00:13:49,040 new jersey and he and i were chatting 362 00:13:53,030 --> 00:13:50,000 earlier today 363 00:13:56,150 --> 00:13:53,040 uh he does uh rock climbing 364 00:13:59,670 --> 00:13:56,160 and he also does swing dancing which 365 00:14:01,670 --> 00:13:59,680 puts him he and i have something really 366 00:14:03,110 --> 00:14:01,680 interesting in common because i did 367 00:14:05,110 --> 00:14:03,120 ballroom dancing at the university of 368 00:14:08,870 --> 00:14:05,120 california berkeley 369 00:14:11,990 --> 00:14:08,880 and both of us met our wives 370 00:14:13,189 --> 00:14:12,000 at the dance club all right so 371 00:14:15,430 --> 00:14:13,199 you never know where you're going to run 372 00:14:17,590 --> 00:14:15,440 into an astrophysicist but 373 00:14:20,230 --> 00:14:17,600 it turns out that maybe a dance club is 374 00:14:22,629 --> 00:14:20,240 a place to find one 375 00:14:24,629 --> 00:14:22,639 i can't guarantee you care your mileage 376 00:14:26,069 --> 00:14:24,639 may vary on things like that 377 00:14:28,629 --> 00:14:26,079 ladies and gentlemen dr mitchell 378 00:14:30,230 --> 00:14:28,639 rawalski 379 00:14:32,150 --> 00:14:30,240 all right thank you so much frank for 380 00:14:32,949 --> 00:14:32,160 that kind introduction and also to 381 00:14:35,269 --> 00:14:32,959 everyone for 382 00:14:36,470 --> 00:14:35,279 joining us online this evening uh 383 00:14:38,949 --> 00:14:36,480 hopefully after the 384 00:14:40,470 --> 00:14:38,959 sad news of arecibo i can uplift your 385 00:14:43,990 --> 00:14:40,480 mood a little bit by giving you 386 00:14:46,870 --> 00:14:44,000 a tour of supermassive black hole winds 387 00:14:49,590 --> 00:14:46,880 and show how they basically shape nearly 388 00:14:51,509 --> 00:14:49,600 every scale of the observable universe 389 00:14:53,670 --> 00:14:51,519 so in the background here we have this 390 00:14:55,829 --> 00:14:53,680 stunning multi-wavelength image that 391 00:14:57,030 --> 00:14:55,839 shows different facets of these black 392 00:14:58,629 --> 00:14:57,040 hole winds 393 00:15:00,870 --> 00:14:58,639 and it's my hope that by the end of the 394 00:15:02,150 --> 00:15:00,880 talk you'll have a strong conceptual 395 00:15:04,389 --> 00:15:02,160 picture of how 396 00:15:06,389 --> 00:15:04,399 supermassive black holes interact with 397 00:15:07,509 --> 00:15:06,399 the galaxies that they live in 398 00:15:09,430 --> 00:15:07,519 so i'll start with a little bit of 399 00:15:11,910 --> 00:15:09,440 background on supermassive black holes 400 00:15:12,389 --> 00:15:11,920 and galaxies and how we study them and 401 00:15:14,230 --> 00:15:12,399 then 402 00:15:15,990 --> 00:15:14,240 go ahead and examine the role of 403 00:15:17,750 --> 00:15:16,000 supermassive black holes in shaping 404 00:15:19,030 --> 00:15:17,760 their galaxy starting from the very 405 00:15:27,590 --> 00:15:19,040 smallest scales 406 00:15:28,949 --> 00:15:27,600 moving out to the very largest scales 407 00:15:30,790 --> 00:15:28,959 so starting at the beginning when we 408 00:15:34,150 --> 00:15:30,800 look out into the universe we see 409 00:15:35,509 --> 00:15:34,160 galaxies almost everywhere and so this 410 00:15:37,430 --> 00:15:35,519 image that you're seeing is the 411 00:15:39,829 --> 00:15:37,440 hubble ultra deep field which is one of 412 00:15:41,110 --> 00:15:39,839 the deepest views of the universe ever 413 00:15:43,509 --> 00:15:41,120 captured by humanity 414 00:15:45,749 --> 00:15:43,519 it required the hubble space telescope 415 00:15:47,749 --> 00:15:45,759 to cumulatively look at the same patch 416 00:15:51,030 --> 00:15:47,759 of the sky for nearly 11 417 00:15:51,910 --> 00:15:51,040 days which is about 400 orbits around 418 00:15:53,829 --> 00:15:51,920 the earth 419 00:15:55,509 --> 00:15:53,839 and so in this image we see galaxies 420 00:15:57,430 --> 00:15:55,519 that are relatively close to us 421 00:15:59,110 --> 00:15:57,440 and we see galaxies at the very furthest 422 00:16:00,949 --> 00:15:59,120 extents of the universe 423 00:16:03,430 --> 00:16:00,959 and so in astronomy we're in this very 424 00:16:06,389 --> 00:16:03,440 unique position because we can actually 425 00:16:08,310 --> 00:16:06,399 look back in time and see these galaxies 426 00:16:08,870 --> 00:16:08,320 as they're growing the further away we 427 00:16:10,790 --> 00:16:08,880 look 428 00:16:12,230 --> 00:16:10,800 it takes the light longer and longer to 429 00:16:13,110 --> 00:16:12,240 reach us and so we're seeing these 430 00:16:16,470 --> 00:16:13,120 galaxies 431 00:16:18,949 --> 00:16:16,480 as they were a very long time ago 432 00:16:20,790 --> 00:16:18,959 now despite all these different types of 433 00:16:22,470 --> 00:16:20,800 galaxies you see in this image 434 00:16:25,030 --> 00:16:22,480 they're all made of the same fundamental 435 00:16:28,310 --> 00:16:25,040 building blocks and that's stars 436 00:16:31,430 --> 00:16:28,320 gas dust and more exotic components like 437 00:16:33,829 --> 00:16:31,440 black holes and dark matter 438 00:16:35,910 --> 00:16:33,839 so we have all these components we can 439 00:16:37,749 --> 00:16:35,920 still classify galaxies into different 440 00:16:39,910 --> 00:16:37,759 types depending on how much they have of 441 00:16:42,069 --> 00:16:39,920 these components on their appearance 442 00:16:43,829 --> 00:16:42,079 such as spiral galaxies elliptical 443 00:16:45,590 --> 00:16:43,839 galaxies irregulars we'll talk about 444 00:16:47,509 --> 00:16:45,600 that a little bit more in a minute 445 00:16:50,069 --> 00:16:47,519 but despite the apparent kind of 446 00:16:52,550 --> 00:16:50,079 emptiness in between these galaxies 447 00:16:55,030 --> 00:16:52,560 there really is gas everywhere we have 448 00:16:55,910 --> 00:16:55,040 gas within galaxies we have gas around 449 00:16:57,829 --> 00:16:55,920 galaxies 450 00:17:00,069 --> 00:16:57,839 and we have gas in the spaces between 451 00:17:01,990 --> 00:17:00,079 galaxies and so depending 452 00:17:03,590 --> 00:17:02,000 on the temperature and the density of 453 00:17:05,270 --> 00:17:03,600 that gas we might need to use different 454 00:17:06,789 --> 00:17:05,280 types of telescopes to see it 455 00:17:08,789 --> 00:17:06,799 but i want you to keep in mind this 456 00:17:09,909 --> 00:17:08,799 picture where galaxies are just filled 457 00:17:12,390 --> 00:17:09,919 and surrounded 458 00:17:14,470 --> 00:17:12,400 with different types of gas and in order 459 00:17:15,909 --> 00:17:14,480 to study the connection between galaxies 460 00:17:16,789 --> 00:17:15,919 and their gas and their supermassive 461 00:17:17,909 --> 00:17:16,799 black holes 462 00:17:19,990 --> 00:17:17,919 we're going to use two of the most 463 00:17:20,789 --> 00:17:20,000 fundamental tools of astronomy which are 464 00:17:23,990 --> 00:17:20,799 imaging 465 00:17:25,350 --> 00:17:24,000 and spectroscopy so those of you who 466 00:17:27,110 --> 00:17:25,360 frequent these public lectures have 467 00:17:28,870 --> 00:17:27,120 probably seen many representations of 468 00:17:30,630 --> 00:17:28,880 the electromagnetic spectrum 469 00:17:32,549 --> 00:17:30,640 and i really like this image because 470 00:17:35,990 --> 00:17:32,559 we're looking at the same galaxy 471 00:17:37,029 --> 00:17:36,000 m51 the famous whirlpool galaxy at each 472 00:17:39,750 --> 00:17:37,039 different section 473 00:17:41,510 --> 00:17:39,760 of the electromagnetic spectrum so light 474 00:17:43,990 --> 00:17:41,520 comes out in the form of photons we can 475 00:17:46,549 --> 00:17:44,000 specify its energy by a wavelength 476 00:17:48,549 --> 00:17:46,559 so starting up here at the top left 477 00:17:49,669 --> 00:17:48,559 we're looking at the longest wavelengths 478 00:17:51,909 --> 00:17:49,679 the radio 479 00:17:53,350 --> 00:17:51,919 moving to the right to the shortest most 480 00:17:56,630 --> 00:17:53,360 energetic wave ranks 481 00:17:58,549 --> 00:17:56,640 at gamma rays so as we sweep through the 482 00:17:59,510 --> 00:17:58,559 electromagnetic spectrum with different 483 00:18:01,510 --> 00:17:59,520 telescopes 484 00:18:03,029 --> 00:18:01,520 we're probing different portions of the 485 00:18:04,630 --> 00:18:03,039 galaxy and its gas 486 00:18:06,630 --> 00:18:04,640 so starting here on the left in the 487 00:18:09,990 --> 00:18:06,640 radio we're probing the very 488 00:18:12,150 --> 00:18:10,000 cold cool dense gas that is basically 489 00:18:14,549 --> 00:18:12,160 the reservoir from which stars can 490 00:18:16,310 --> 00:18:14,559 form and as we'll see the radio will 491 00:18:18,549 --> 00:18:16,320 actually also be useful for probing some 492 00:18:20,230 --> 00:18:18,559 of that most energetic phenomenon within 493 00:18:22,070 --> 00:18:20,240 galaxies 494 00:18:23,990 --> 00:18:22,080 as we move over to the right we're 495 00:18:25,510 --> 00:18:24,000 looking at the infrared and here we're 496 00:18:28,230 --> 00:18:25,520 starting to probe the warm 497 00:18:29,669 --> 00:18:28,240 dust and the cool stars within galaxies 498 00:18:32,470 --> 00:18:29,679 and this has been most famously done 499 00:18:34,230 --> 00:18:32,480 using the spitzer space telescope 500 00:18:35,990 --> 00:18:34,240 as we continue on into the center we're 501 00:18:37,669 --> 00:18:36,000 looking at optical or visible 502 00:18:39,430 --> 00:18:37,679 wavelengths and these are the colors 503 00:18:40,549 --> 00:18:39,440 that our eyes are sensitive to that 504 00:18:43,430 --> 00:18:40,559 we're able to 505 00:18:45,990 --> 00:18:43,440 detect and perceive and this is probing 506 00:18:48,150 --> 00:18:46,000 gas that's maybe a few thousand degrees 507 00:18:49,669 --> 00:18:48,160 looking at some of the hotter stars and 508 00:18:51,430 --> 00:18:49,679 by far one of the most famous and 509 00:18:53,270 --> 00:18:51,440 successful observatories for doing this 510 00:18:54,549 --> 00:18:53,280 type of astronomy is the hubble space 511 00:18:56,390 --> 00:18:54,559 telescope 512 00:18:58,390 --> 00:18:56,400 as we continue on moving to higher 513 00:19:00,870 --> 00:18:58,400 energies looking at the ultraviolet and 514 00:19:02,630 --> 00:19:00,880 x-rays we're looking at gas that's tens 515 00:19:04,789 --> 00:19:02,640 of thousands or even hundreds of 516 00:19:06,310 --> 00:19:04,799 thousands or millions of degrees 517 00:19:08,150 --> 00:19:06,320 and so this is often done in the 518 00:19:09,990 --> 00:19:08,160 ultraviolet and the x-rays 519 00:19:12,549 --> 00:19:10,000 using instruments such as the chandra 520 00:19:15,029 --> 00:19:12,559 x-ray observatory 521 00:19:15,590 --> 00:19:15,039 so this is the first tool in our kit in 522 00:19:17,909 --> 00:19:15,600 order to 523 00:19:19,830 --> 00:19:17,919 understand the universe we have an image 524 00:19:21,750 --> 00:19:19,840 we open our telescope up we allow the 525 00:19:23,590 --> 00:19:21,760 light to hit a detector and it shows us 526 00:19:25,350 --> 00:19:23,600 the distribution of gas and dust and 527 00:19:26,549 --> 00:19:25,360 stars within galaxies 528 00:19:28,710 --> 00:19:26,559 the second tool of course is 529 00:19:30,549 --> 00:19:28,720 spectroscopy and so 530 00:19:32,390 --> 00:19:30,559 a famous saying is that if a picture is 531 00:19:34,150 --> 00:19:32,400 worth a thousand words then a spectrum 532 00:19:36,390 --> 00:19:34,160 is worth a thousand pictures 533 00:19:37,669 --> 00:19:36,400 meaning that we can get an enormous 534 00:19:39,510 --> 00:19:37,679 amount of information 535 00:19:41,350 --> 00:19:39,520 from the spectrum of an object we can 536 00:19:43,430 --> 00:19:41,360 learn a lot more than we could 537 00:19:45,270 --> 00:19:43,440 by simply having an image so 538 00:19:47,190 --> 00:19:45,280 spectroscopy is the process of taking 539 00:19:48,230 --> 00:19:47,200 light from a galaxy or a portion of a 540 00:19:50,390 --> 00:19:48,240 galaxy 541 00:19:52,070 --> 00:19:50,400 we pass it through a spectrograph on 542 00:19:54,549 --> 00:19:52,080 board of our telescope in this case 543 00:19:56,070 --> 00:19:54,559 i have a little hubble space telescope 544 00:19:57,990 --> 00:19:56,080 and then we spread it out 545 00:19:59,830 --> 00:19:58,000 as a function of wavelength or color so 546 00:20:01,430 --> 00:19:59,840 either by passing it through a prism or 547 00:20:03,110 --> 00:20:01,440 bouncing it off a grating 548 00:20:06,230 --> 00:20:03,120 we spread that light out and then we 549 00:20:07,830 --> 00:20:06,240 record the intensity of the light as a 550 00:20:09,750 --> 00:20:07,840 function of wavelength 551 00:20:11,510 --> 00:20:09,760 so we do this we can take this spectrum 552 00:20:12,950 --> 00:20:11,520 on the right and we can measure the 553 00:20:15,190 --> 00:20:12,960 intensity of each color 554 00:20:16,070 --> 00:20:15,200 and we get a more familiar spectrum and 555 00:20:17,350 --> 00:20:16,080 this has a couple 556 00:20:19,350 --> 00:20:17,360 key features that are really going to 557 00:20:21,350 --> 00:20:19,360 help us in our studies 558 00:20:23,110 --> 00:20:21,360 first we just have the underlying level 559 00:20:25,029 --> 00:20:23,120 of light at all colors this is the 560 00:20:25,669 --> 00:20:25,039 continuum emission this is primarily 561 00:20:28,630 --> 00:20:25,679 coming 562 00:20:30,070 --> 00:20:28,640 from hot stars and dust within a galaxy 563 00:20:31,350 --> 00:20:30,080 and then on top of that we can have 564 00:20:34,070 --> 00:20:31,360 these very 565 00:20:34,549 --> 00:20:34,080 straight narrow features called emission 566 00:20:36,630 --> 00:20:34,559 lines 567 00:20:38,070 --> 00:20:36,640 so we have this excess of light at a 568 00:20:39,909 --> 00:20:38,080 very specific color 569 00:20:42,070 --> 00:20:39,919 and this is coming from the gas this is 570 00:20:43,909 --> 00:20:42,080 coming from individual atoms which have 571 00:20:45,990 --> 00:20:43,919 electrons going around them 572 00:20:47,830 --> 00:20:46,000 and as those electrons are excited and 573 00:20:48,710 --> 00:20:47,840 de-excited they jump between very 574 00:20:50,789 --> 00:20:48,720 discrete 575 00:20:52,950 --> 00:20:50,799 very well-known energy levels and so you 576 00:20:56,390 --> 00:20:52,960 get a very specific color a very 577 00:20:58,950 --> 00:20:56,400 specific wavelength of that photon 578 00:21:00,390 --> 00:20:58,960 the converse of this is absorption lines 579 00:21:01,510 --> 00:21:00,400 we're basically absorbing a very 580 00:21:03,190 --> 00:21:01,520 specific color 581 00:21:04,950 --> 00:21:03,200 and all these features are very 582 00:21:06,390 --> 00:21:04,960 important because they tell us a lot of 583 00:21:08,549 --> 00:21:06,400 information about the gas 584 00:21:10,549 --> 00:21:08,559 most specifically they tell us about the 585 00:21:12,630 --> 00:21:10,559 velocity of this material 586 00:21:14,310 --> 00:21:12,640 so the locations of these emission lines 587 00:21:15,270 --> 00:21:14,320 are very well known for measuring them 588 00:21:17,510 --> 00:21:15,280 in the lab 589 00:21:19,270 --> 00:21:17,520 but due to the doppler effect if objects 590 00:21:22,070 --> 00:21:19,280 are moving either toward 591 00:21:23,510 --> 00:21:22,080 or away from us the lines will be blue 592 00:21:25,510 --> 00:21:23,520 shifted or red shifted 593 00:21:26,549 --> 00:21:25,520 moving to shorter or longer wavelengths 594 00:21:28,390 --> 00:21:26,559 within the spectrum 595 00:21:30,630 --> 00:21:28,400 so basically we can use the positions of 596 00:21:32,549 --> 00:21:30,640 these lines to measure the velocities of 597 00:21:34,230 --> 00:21:32,559 things in space 598 00:21:36,630 --> 00:21:34,240 so we're going to go ahead and apply 599 00:21:37,669 --> 00:21:36,640 these tools to the different portions of 600 00:21:39,590 --> 00:21:37,679 galaxies 601 00:21:40,789 --> 00:21:39,600 and so here we have on the left an 602 00:21:43,029 --> 00:21:40,799 example of a more of an 603 00:21:45,669 --> 00:21:43,039 edge on spiral galaxy and on the right 604 00:21:47,669 --> 00:21:45,679 we have more of a face on spiral galaxy 605 00:21:49,510 --> 00:21:47,679 and down in the very center we have the 606 00:21:50,390 --> 00:21:49,520 nucleus this is the very center of the 607 00:21:52,549 --> 00:21:50,400 galaxy 608 00:21:53,750 --> 00:21:52,559 and around that we have the bulge and 609 00:21:56,390 --> 00:21:53,760 this is basically kind of a 610 00:21:59,029 --> 00:21:56,400 semi-spherical distribution of stars 611 00:22:00,950 --> 00:21:59,039 that are all orbiting around the nucleus 612 00:22:01,669 --> 00:22:00,960 typically made up of older stars as 613 00:22:04,870 --> 00:22:01,679 compared to 614 00:22:06,549 --> 00:22:04,880 hotter younger stars in this case we 615 00:22:08,710 --> 00:22:06,559 also have spiral arms 616 00:22:09,590 --> 00:22:08,720 and these are regions that are slightly 617 00:22:11,830 --> 00:22:09,600 more dense 618 00:22:12,630 --> 00:22:11,840 in hot stars and gas and dust and they 619 00:22:14,230 --> 00:22:12,640 make these very 620 00:22:15,669 --> 00:22:14,240 intricate shapes that we can see in 621 00:22:16,870 --> 00:22:15,679 these spiral galaxies 622 00:22:18,470 --> 00:22:16,880 now of course these are not the only 623 00:22:20,149 --> 00:22:18,480 type there's also ellipticals which you 624 00:22:20,950 --> 00:22:20,159 can almost think of as just one giant 625 00:22:23,590 --> 00:22:20,960 bulge with 626 00:22:25,590 --> 00:22:23,600 much less gas and much less dust as well 627 00:22:27,430 --> 00:22:25,600 as irregulars and types like that 628 00:22:28,710 --> 00:22:27,440 but a profound discovery to come out of 629 00:22:30,789 --> 00:22:28,720 the last few decades 630 00:22:31,990 --> 00:22:30,799 is that almost all massive galaxies at 631 00:22:34,909 --> 00:22:32,000 their centers have 632 00:22:36,710 --> 00:22:34,919 a super massive black hole abbreviated 633 00:22:38,710 --> 00:22:36,720 smbh 634 00:22:40,070 --> 00:22:38,720 now in this case i've drawn these dots 635 00:22:41,669 --> 00:22:40,080 and they're actually much too 636 00:22:43,350 --> 00:22:41,679 large for the scale of the galaxy 637 00:22:45,270 --> 00:22:43,360 supermassive black holes are actually 638 00:22:47,510 --> 00:22:45,280 very small at the distances of these 639 00:22:48,070 --> 00:22:47,520 galaxies and so a logical question might 640 00:22:49,590 --> 00:22:48,080 be well 641 00:22:52,149 --> 00:22:49,600 how do we actually know that they're 642 00:22:53,990 --> 00:22:52,159 even there and so the best evidence of 643 00:22:56,630 --> 00:22:54,000 this comes from looking at the center 644 00:22:58,390 --> 00:22:56,640 of our very own galaxy so here we're 645 00:23:00,549 --> 00:22:58,400 looking at the center of our galaxy and 646 00:23:01,590 --> 00:23:00,559 we're tracing the motions of stars 647 00:23:04,470 --> 00:23:01,600 around the center 648 00:23:06,230 --> 00:23:04,480 over the course of about 20 years and by 649 00:23:06,870 --> 00:23:06,240 doing this we can see that all of these 650 00:23:09,190 --> 00:23:06,880 stars are 651 00:23:11,110 --> 00:23:09,200 orbiting around the central point marked 652 00:23:13,430 --> 00:23:11,120 by a star 653 00:23:14,789 --> 00:23:13,440 however when we point the majority of 654 00:23:17,590 --> 00:23:14,799 our telescopes there 655 00:23:19,430 --> 00:23:17,600 we don't really see anything so based on 656 00:23:21,190 --> 00:23:19,440 the physics that we know we can see how 657 00:23:22,390 --> 00:23:21,200 fast these stars are moving how tight 658 00:23:24,549 --> 00:23:22,400 their orbits are 659 00:23:25,909 --> 00:23:24,559 and we can calculate how much mass has 660 00:23:28,149 --> 00:23:25,919 to be there to actually 661 00:23:29,590 --> 00:23:28,159 hold those stars in those tight orbits 662 00:23:32,070 --> 00:23:29,600 and it turns out to be 663 00:23:33,110 --> 00:23:32,080 millions of times the mass of our own 664 00:23:35,350 --> 00:23:33,120 sun 665 00:23:36,230 --> 00:23:35,360 so we have something that is very very 666 00:23:38,149 --> 00:23:36,240 massive 667 00:23:40,310 --> 00:23:38,159 not really emitting any light and it's 668 00:23:41,750 --> 00:23:40,320 very very dense because these stars are 669 00:23:43,669 --> 00:23:41,760 orbiting very close 670 00:23:46,230 --> 00:23:43,679 and so the only objects that we know of 671 00:23:48,870 --> 00:23:46,240 that can be that dense and that massive 672 00:23:50,070 --> 00:23:48,880 are supermassive black holes these are 673 00:23:52,390 --> 00:23:50,080 objects that range from 674 00:23:54,149 --> 00:23:52,400 millions to even billions of times the 675 00:23:56,630 --> 00:23:54,159 mass of our own sun 676 00:23:58,310 --> 00:23:56,640 and it's all crushed down into a volume 677 00:24:00,630 --> 00:23:58,320 about the size of the solar system 678 00:24:02,870 --> 00:24:00,640 depending on its mass 679 00:24:04,070 --> 00:24:02,880 so this is incredible result that was 680 00:24:06,630 --> 00:24:04,080 finally really 681 00:24:07,510 --> 00:24:06,640 fully solidified and recognized just 682 00:24:10,310 --> 00:24:07,520 this year with the 683 00:24:11,830 --> 00:24:10,320 2020 nobel prize in physics which was 684 00:24:13,990 --> 00:24:11,840 recently awarded to these three 685 00:24:16,230 --> 00:24:14,000 individuals for their pioneering work 686 00:24:18,630 --> 00:24:16,240 to prove beyond a reasonable doubt that 687 00:24:20,230 --> 00:24:18,640 supermassive black holes exist 688 00:24:22,230 --> 00:24:20,240 and are at the centers of the majority 689 00:24:23,510 --> 00:24:22,240 of galaxies 690 00:24:25,430 --> 00:24:23,520 so for the most part when we look at 691 00:24:27,590 --> 00:24:25,440 galaxies we have this kind of invisible 692 00:24:28,549 --> 00:24:27,600 or indirect view of supermassive black 693 00:24:30,230 --> 00:24:28,559 holes 694 00:24:31,990 --> 00:24:30,240 but that changes when we look at 695 00:24:35,110 --> 00:24:32,000 supermassive black holes that are 696 00:24:38,310 --> 00:24:35,120 actively growing or eating material 697 00:24:40,390 --> 00:24:38,320 and these are active galaxies or active 698 00:24:42,230 --> 00:24:40,400 galactic nuclei 699 00:24:44,950 --> 00:24:42,240 so here on the right we have an artist 700 00:24:46,070 --> 00:24:44,960 conception of basically a supermassive 701 00:24:48,149 --> 00:24:46,080 black hole 702 00:24:49,590 --> 00:24:48,159 material in the galaxy works its way 703 00:24:51,750 --> 00:24:49,600 down into the center 704 00:24:53,669 --> 00:24:51,760 and as it starts to fall into the strong 705 00:24:54,310 --> 00:24:53,679 gravitational potential of the black 706 00:24:56,630 --> 00:24:54,320 hole 707 00:24:58,230 --> 00:24:56,640 it will become compressed will form an 708 00:24:59,029 --> 00:24:58,240 accretion disk of material that's 709 00:25:01,269 --> 00:24:59,039 accreting 710 00:25:03,909 --> 00:25:01,279 to the supermassive black hole it will 711 00:25:04,950 --> 00:25:03,919 heat up and it'll emit an immense amount 712 00:25:07,110 --> 00:25:04,960 of radiation 713 00:25:07,990 --> 00:25:07,120 all across the electromagnetic spectrum 714 00:25:09,750 --> 00:25:08,000 from the radio 715 00:25:13,350 --> 00:25:09,760 to the infrared the visible the 716 00:25:15,669 --> 00:25:13,360 ultraviolet the x-rays and onward 717 00:25:16,789 --> 00:25:15,679 so the way that we kind of characterize 718 00:25:18,549 --> 00:25:16,799 this process 719 00:25:20,710 --> 00:25:18,559 that we talk about different active 720 00:25:22,390 --> 00:25:20,720 galaxies that we compare their power 721 00:25:24,230 --> 00:25:22,400 is through what's called the luminosity 722 00:25:27,029 --> 00:25:24,240 and so this is the total amount of 723 00:25:28,149 --> 00:25:27,039 energy that's being emitted at one time 724 00:25:30,789 --> 00:25:28,159 due to this process 725 00:25:32,230 --> 00:25:30,799 of material falling onto the black hole 726 00:25:35,029 --> 00:25:32,240 and 727 00:25:37,110 --> 00:25:35,039 this ranges from about a million times 728 00:25:39,190 --> 00:25:37,120 the luminosity of our own sun 729 00:25:41,430 --> 00:25:39,200 which is about the same as one really 730 00:25:43,350 --> 00:25:41,440 bright massive o star the largest stars 731 00:25:45,990 --> 00:25:43,360 we see in most galaxies 732 00:25:48,549 --> 00:25:46,000 all the way up to hundreds of trillions 733 00:25:51,590 --> 00:25:48,559 of times the luminosity of our own sun 734 00:25:53,830 --> 00:25:51,600 so in the most powerful active galaxies 735 00:25:55,430 --> 00:25:53,840 the amount of radiation coming from very 736 00:25:57,350 --> 00:25:55,440 near the supermassive black hole can 737 00:26:00,230 --> 00:25:57,360 actually outshine the light of 738 00:26:01,830 --> 00:26:00,240 all the stars in the entire galaxy so 739 00:26:03,510 --> 00:26:01,840 this is going to be a very fundamental 740 00:26:04,870 --> 00:26:03,520 parameter that we're going to use 741 00:26:07,190 --> 00:26:04,880 when we're talking about these active 742 00:26:08,070 --> 00:26:07,200 galaxies the luminosity the total amount 743 00:26:10,470 --> 00:26:08,080 of energy 744 00:26:13,190 --> 00:26:10,480 that's being radiated by this process of 745 00:26:15,510 --> 00:26:13,200 material falling onto the black hole 746 00:26:17,029 --> 00:26:15,520 now all this energy has to go somewhere 747 00:26:19,190 --> 00:26:17,039 it doesn't just disappear 748 00:26:21,510 --> 00:26:19,200 and so this is where our supermassive 749 00:26:23,430 --> 00:26:21,520 black hole winds come into play 750 00:26:24,710 --> 00:26:23,440 this energy in the form of light in the 751 00:26:27,830 --> 00:26:24,720 form of photons 752 00:26:29,750 --> 00:26:27,840 is traveling out back into the galaxy 753 00:26:31,909 --> 00:26:29,760 it can interact with the gas it can 754 00:26:33,190 --> 00:26:31,919 excite it it can ionize it cause it to 755 00:26:35,269 --> 00:26:33,200 glow like a neon 756 00:26:36,950 --> 00:26:35,279 sign and more than that we have such 757 00:26:38,070 --> 00:26:36,960 intense radiation that it's actually 758 00:26:40,470 --> 00:26:38,080 exerting a force 759 00:26:41,830 --> 00:26:40,480 actually inverted in it's actually 760 00:26:44,870 --> 00:26:41,840 imparting momentum 761 00:26:47,029 --> 00:26:44,880 onto this gas and pushing it potentially 762 00:26:48,789 --> 00:26:47,039 away from the supermassive black hole 763 00:26:50,870 --> 00:26:48,799 and so this is what we call mass 764 00:26:53,990 --> 00:26:50,880 outflows or winds i'm going to use those 765 00:26:56,470 --> 00:26:54,000 two phrases somewhat interchangeably 766 00:26:57,269 --> 00:26:56,480 now these appear in kind of two main 767 00:26:59,510 --> 00:26:57,279 forms 768 00:27:01,590 --> 00:26:59,520 the first is these mass outflows where 769 00:27:03,510 --> 00:27:01,600 we have radiation that's traveling out 770 00:27:05,110 --> 00:27:03,520 into the galaxy it's finding gas 771 00:27:06,390 --> 00:27:05,120 somewhere exciting it 772 00:27:08,870 --> 00:27:06,400 and then moving it away from the 773 00:27:09,590 --> 00:27:08,880 supermassive black hole and then we also 774 00:27:11,990 --> 00:27:09,600 have 775 00:27:13,269 --> 00:27:12,000 radio jets and so this is a somewhat 776 00:27:15,190 --> 00:27:13,279 different phenomenon 777 00:27:17,029 --> 00:27:15,200 and so here what we have is very close 778 00:27:18,630 --> 00:27:17,039 to the supermassive black hole 779 00:27:20,630 --> 00:27:18,640 there's an immense amount of energy we 780 00:27:21,909 --> 00:27:20,640 have twisting magnetic fields all sorts 781 00:27:23,990 --> 00:27:21,919 of intense physics 782 00:27:25,190 --> 00:27:24,000 and this is basically able to launch a 783 00:27:27,669 --> 00:27:25,200 potential beam of 784 00:27:30,149 --> 00:27:27,679 particles away from the supermassive 785 00:27:31,750 --> 00:27:30,159 black hole at very very high velocities 786 00:27:33,590 --> 00:27:31,760 and so these are much narrower they're 787 00:27:35,669 --> 00:27:33,600 much more directed but they 788 00:27:37,350 --> 00:27:35,679 may have much less material so these are 789 00:27:39,350 --> 00:27:37,360 kind of the two main types of 790 00:27:41,110 --> 00:27:39,360 outflows that i'm going to be focusing 791 00:27:42,950 --> 00:27:41,120 on tonight 792 00:27:44,389 --> 00:27:42,960 so with this we have nearly everything 793 00:27:46,310 --> 00:27:44,399 that we need to investigate the 794 00:27:48,070 --> 00:27:46,320 supermassive black hole winds 795 00:27:49,909 --> 00:27:48,080 let's go ahead and just paint the big 796 00:27:51,990 --> 00:27:49,919 picture so here 797 00:27:53,750 --> 00:27:52,000 on the right we have an artist kind of 798 00:27:56,870 --> 00:27:53,760 version of a typical 799 00:27:58,549 --> 00:27:56,880 say milky way like galaxy and 800 00:28:00,789 --> 00:27:58,559 we like to measure distances in 801 00:28:01,350 --> 00:28:00,799 astronomy using parsecs where a parsec 802 00:28:03,190 --> 00:28:01,360 is about 803 00:28:05,350 --> 00:28:03,200 three light years so anytime you hear a 804 00:28:08,070 --> 00:28:05,360 parsec you can think three light years 805 00:28:09,350 --> 00:28:08,080 and just like grams and kilograms we use 806 00:28:11,909 --> 00:28:09,360 suffixes to give 807 00:28:14,310 --> 00:28:11,919 larger distances so a thousand parsecs 808 00:28:16,149 --> 00:28:14,320 is a kiloparsec 809 00:28:18,149 --> 00:28:16,159 so everything i've shown you so far the 810 00:28:20,389 --> 00:28:18,159 supermassive black hole it's accretion 811 00:28:22,789 --> 00:28:20,399 disk this whole energetic environment 812 00:28:23,909 --> 00:28:22,799 is all contained down at the very center 813 00:28:25,510 --> 00:28:23,919 of the galaxy 814 00:28:28,230 --> 00:28:25,520 if you look at this image on the right 815 00:28:30,710 --> 00:28:28,240 i'll highlight the center most portion 816 00:28:32,230 --> 00:28:30,720 so all of this is contained on scales of 817 00:28:34,149 --> 00:28:32,240 less than a parsec 818 00:28:36,310 --> 00:28:34,159 nearly less than a light year so i've 819 00:28:38,310 --> 00:28:36,320 highlighted that with a single red pixel 820 00:28:40,230 --> 00:28:38,320 on this image and that's actually too 821 00:28:42,389 --> 00:28:40,240 large it should be even smaller than 822 00:28:45,990 --> 00:28:42,399 that and so that's just to highlight 823 00:28:47,669 --> 00:28:46,000 just how tiny these very massive dense 824 00:28:49,110 --> 00:28:47,679 objects are on the scales of their 825 00:28:50,870 --> 00:28:49,120 galaxies 826 00:28:52,230 --> 00:28:50,880 the next scale as we move out is the 827 00:28:54,230 --> 00:28:52,240 galaxy bulge 828 00:28:56,149 --> 00:28:54,240 and so this is on scales of about one 829 00:28:58,870 --> 00:28:56,159 thousand to three thousand parsecs or 830 00:29:01,190 --> 00:28:58,880 one to three kiloparsecs 831 00:29:03,029 --> 00:29:01,200 continuing on past that we have the 832 00:29:04,710 --> 00:29:03,039 stellar disk of the galaxy 833 00:29:06,950 --> 00:29:04,720 and so this is basically the extent of 834 00:29:08,710 --> 00:29:06,960 the galaxy as traced by the stars 835 00:29:10,549 --> 00:29:08,720 and this varies depending on the type of 836 00:29:12,630 --> 00:29:10,559 galaxy but it might be something on the 837 00:29:13,510 --> 00:29:12,640 order of say 30 kiloparsecs which is 838 00:29:16,470 --> 00:29:13,520 about a hundred 839 00:29:18,389 --> 00:29:16,480 thousand light years and finally in the 840 00:29:20,149 --> 00:29:18,399 region outside of the galaxy where we 841 00:29:21,590 --> 00:29:20,159 might not see many stars but we still 842 00:29:24,070 --> 00:29:21,600 have lots of gas 843 00:29:25,430 --> 00:29:24,080 this is the circum galactic medium where 844 00:29:28,149 --> 00:29:25,440 the circum galactic region 845 00:29:28,789 --> 00:29:28,159 around these galaxies so these are kind 846 00:29:30,389 --> 00:29:28,799 of the four 847 00:29:32,230 --> 00:29:30,399 fundamental scales that we're going to 848 00:29:34,549 --> 00:29:32,240 focus on when looking at these 849 00:29:36,070 --> 00:29:34,559 supermassive black hole winds 850 00:29:37,750 --> 00:29:36,080 so now you have all the background you 851 00:29:39,669 --> 00:29:37,760 need we can dive in 852 00:29:42,070 --> 00:29:39,679 and we can tackle this from two points 853 00:29:44,870 --> 00:29:42,080 of view we can look at these wins from 854 00:29:49,350 --> 00:29:44,880 simulations or we can look at them from 855 00:29:53,350 --> 00:29:51,430 so simulations and observations both 856 00:29:55,110 --> 00:29:53,360 tell us something somewhat different 857 00:29:57,430 --> 00:29:55,120 but they're complementary by learning 858 00:29:58,549 --> 00:29:57,440 from one we can use that information to 859 00:30:00,230 --> 00:29:58,559 inform the other 860 00:30:02,149 --> 00:30:00,240 and then rotate through to try to 861 00:30:03,510 --> 00:30:02,159 understand the physics at work 862 00:30:05,750 --> 00:30:03,520 so we're going to go ahead and start 863 00:30:06,470 --> 00:30:05,760 with simulations so let's take the 864 00:30:09,029 --> 00:30:06,480 universe 865 00:30:10,470 --> 00:30:09,039 let's put it in a box let's apply all 866 00:30:13,029 --> 00:30:10,480 the physics that we know 867 00:30:14,549 --> 00:30:13,039 and let's see how it evolves over time 868 00:30:16,630 --> 00:30:14,559 so in this simulation 869 00:30:18,789 --> 00:30:16,640 we're looking at the temperature of gas 870 00:30:19,269 --> 00:30:18,799 in the universe from the very earliest 871 00:30:21,909 --> 00:30:19,279 times 872 00:30:23,510 --> 00:30:21,919 moving towards the present day and so 873 00:30:26,549 --> 00:30:23,520 what you see here is this 874 00:30:28,789 --> 00:30:26,559 long filamentary like structure 875 00:30:30,789 --> 00:30:28,799 all these different pieces of gas and we 876 00:30:33,430 --> 00:30:30,799 have the very cool gas in blue 877 00:30:34,549 --> 00:30:33,440 warmer gas and green and the hottest gas 878 00:30:36,230 --> 00:30:34,559 in red 879 00:30:38,549 --> 00:30:36,240 so these big structures here these are 880 00:30:39,990 --> 00:30:38,559 whole groups of galaxies clusters of 881 00:30:41,350 --> 00:30:40,000 galaxies we're looking at the very 882 00:30:43,190 --> 00:30:41,360 biggest scales 883 00:30:44,950 --> 00:30:43,200 and what you start to see are these 884 00:30:46,710 --> 00:30:44,960 pockets of red basically 885 00:30:48,870 --> 00:30:46,720 exploding out of these groups of 886 00:30:51,510 --> 00:30:48,880 galaxies and so these are 887 00:30:52,230 --> 00:30:51,520 our agn these are super massive black 888 00:30:55,350 --> 00:30:52,240 holes 889 00:30:57,430 --> 00:30:55,360 that are eating material and pushing an 890 00:30:59,990 --> 00:30:57,440 immense amount of energy and radiation 891 00:31:02,310 --> 00:31:00,000 out beyond the galaxy and heating up and 892 00:31:04,630 --> 00:31:02,320 moving this gas 893 00:31:06,149 --> 00:31:04,640 so this is these simulations are 894 00:31:07,509 --> 00:31:06,159 absolutely incredible this one 895 00:31:10,870 --> 00:31:07,519 in particular is from the illustrious 896 00:31:12,870 --> 00:31:10,880 group and so these allow us to control 897 00:31:15,110 --> 00:31:12,880 the different aspects of what's going on 898 00:31:17,190 --> 00:31:15,120 and understand the physics in detail 899 00:31:18,870 --> 00:31:17,200 despite how incredible these simulations 900 00:31:20,470 --> 00:31:18,880 are we still just don't have the 901 00:31:22,950 --> 00:31:20,480 computational power 902 00:31:24,230 --> 00:31:22,960 to simulate all the different scales 903 00:31:26,149 --> 00:31:24,240 that we just talked about 904 00:31:27,830 --> 00:31:26,159 so if you want to simulate material 905 00:31:29,909 --> 00:31:27,840 falling into a black hole 906 00:31:31,509 --> 00:31:29,919 simulate individual galaxies and then 907 00:31:33,269 --> 00:31:31,519 simulate the entire universe we just 908 00:31:33,909 --> 00:31:33,279 don't have the computational power to do 909 00:31:35,350 --> 00:31:33,919 that 910 00:31:37,669 --> 00:31:35,360 and so what we do here is we use 911 00:31:39,029 --> 00:31:37,679 different numerical recipes 912 00:31:41,269 --> 00:31:39,039 basically we say okay on the smallest 913 00:31:43,269 --> 00:31:41,279 scales let's just say that we know how 914 00:31:44,149 --> 00:31:43,279 much energy is being injected by these 915 00:31:45,750 --> 00:31:44,159 agn 916 00:31:48,149 --> 00:31:45,760 and then we'll follow it and watch what 917 00:31:49,590 --> 00:31:48,159 happens and so 918 00:31:51,830 --> 00:31:49,600 one of the things that's very critical 919 00:31:54,149 --> 00:31:51,840 here is the result that you get 920 00:31:55,590 --> 00:31:54,159 depends very strongly on how you tweak 921 00:31:56,870 --> 00:31:55,600 those parameters 922 00:31:59,190 --> 00:31:56,880 so here towards the end of the 923 00:32:00,549 --> 00:31:59,200 simulation you can see that we have all 924 00:32:02,710 --> 00:32:00,559 this hot gas 925 00:32:03,750 --> 00:32:02,720 that's permeating all throughout between 926 00:32:06,149 --> 00:32:03,760 these different 927 00:32:07,669 --> 00:32:06,159 galaxies and clusters of galaxies but 928 00:32:09,029 --> 00:32:07,679 now if we go ahead and update the 929 00:32:11,669 --> 00:32:09,039 physics a little bit 930 00:32:14,389 --> 00:32:11,679 and we look at what happens if we try to 931 00:32:16,389 --> 00:32:14,399 understand the efficiency of how this 932 00:32:18,070 --> 00:32:16,399 radiation is produced and how it moves 933 00:32:19,750 --> 00:32:18,080 out and couples with gas 934 00:32:22,070 --> 00:32:19,760 if we go ahead and fine-tune those 935 00:32:23,909 --> 00:32:22,080 parameters based on what we know now 936 00:32:25,590 --> 00:32:23,919 we see that in just a few years these 937 00:32:26,389 --> 00:32:25,600 simulations give somewhat different 938 00:32:29,269 --> 00:32:26,399 answers 939 00:32:30,950 --> 00:32:29,279 so we still have this hot excited gas 940 00:32:32,789 --> 00:32:30,960 but now on the right we can see that 941 00:32:34,630 --> 00:32:32,799 it's very hot but more condensed it's 942 00:32:36,870 --> 00:32:34,640 more it's held more closely to these 943 00:32:38,870 --> 00:32:36,880 clusters these groups of galaxies 944 00:32:40,149 --> 00:32:38,880 and so the overall picture is somewhat 945 00:32:42,549 --> 00:32:40,159 different 946 00:32:44,230 --> 00:32:42,559 and so the way that we can improve these 947 00:32:46,070 --> 00:32:44,240 simulations and inform them 948 00:32:47,909 --> 00:32:46,080 is by going ahead and actually doing 949 00:32:50,630 --> 00:32:47,919 detailed observations 950 00:32:51,269 --> 00:32:50,640 of the supermassive black hole winds to 951 00:32:54,710 --> 00:32:51,279 understand 952 00:32:56,070 --> 00:32:54,720 just how they work 953 00:32:57,990 --> 00:32:56,080 and then we can iterate between 954 00:33:00,230 --> 00:32:58,000 simulations and observations to learn 955 00:33:02,389 --> 00:33:00,240 all the physics involved 956 00:33:04,549 --> 00:33:02,399 so now we're ready to transition to 957 00:33:05,430 --> 00:33:04,559 observations starting here with our big 958 00:33:07,430 --> 00:33:05,440 picture 959 00:33:09,590 --> 00:33:07,440 we're going to go ahead at the closest 960 00:33:11,190 --> 00:33:09,600 in scales right near the supermassive 961 00:33:13,750 --> 00:33:11,200 black hole in the accretion disk 962 00:33:15,190 --> 00:33:13,760 on scales of less than a light year and 963 00:33:16,870 --> 00:33:15,200 so because we're so close to the 964 00:33:19,669 --> 00:33:16,880 supermassive black hole we're generally 965 00:33:21,909 --> 00:33:19,679 looking at the highest energy radiation 966 00:33:23,590 --> 00:33:21,919 which is most often observed in the 967 00:33:28,630 --> 00:33:23,600 x-rays 968 00:33:30,870 --> 00:33:28,640 showed some sort of signature in the 969 00:33:33,269 --> 00:33:30,880 spectra there was something going on 970 00:33:33,990 --> 00:33:33,279 but x-ray spectroscopy is really 971 00:33:36,549 --> 00:33:34,000 difficult 972 00:33:37,750 --> 00:33:36,559 x-rays are very high energy if you try 973 00:33:39,269 --> 00:33:37,760 to bounce them off a 974 00:33:40,950 --> 00:33:39,279 normal type of mirror that you're used 975 00:33:41,909 --> 00:33:40,960 to looking at they'll just go right 976 00:33:43,430 --> 00:33:41,919 through it 977 00:33:45,830 --> 00:33:43,440 and so you have to build a very 978 00:33:47,669 --> 00:33:45,840 specialized telescope with a series of 979 00:33:49,830 --> 00:33:47,679 ring-like mirrors that will basically 980 00:33:51,669 --> 00:33:49,840 bounce that photon and get it down 981 00:33:53,110 --> 00:33:51,679 onto the detector where you want to 982 00:33:55,830 --> 00:33:53,120 analyze it 983 00:33:57,750 --> 00:33:55,840 and so this was really revolutionized by 984 00:33:59,830 --> 00:33:57,760 newer space missions such as the chandra 985 00:34:01,750 --> 00:33:59,840 x-ray observatory suzaku 986 00:34:03,990 --> 00:34:01,760 and the x-ray multi-mirror mission 987 00:34:06,149 --> 00:34:04,000 telescope shown here on the right 988 00:34:07,909 --> 00:34:06,159 and so after looking at more and more of 989 00:34:10,710 --> 00:34:07,919 these active galaxies 990 00:34:13,270 --> 00:34:10,720 and looking at um a large archive of 991 00:34:14,710 --> 00:34:13,280 data really just in the last 10 years 992 00:34:16,470 --> 00:34:14,720 is when we've been able to establish 993 00:34:18,550 --> 00:34:16,480 that there is indeed these 994 00:34:20,710 --> 00:34:18,560 winds very close to the supermassive 995 00:34:21,909 --> 00:34:20,720 black hole and as the title alludes to 996 00:34:25,510 --> 00:34:21,919 these are called 997 00:34:27,669 --> 00:34:25,520 ultra fast outflows or ufos yes that is 998 00:34:29,669 --> 00:34:27,679 actually the acronym 999 00:34:31,190 --> 00:34:29,679 so you can see here on the right is one 1000 00:34:33,349 --> 00:34:31,200 of these x-ray spectra 1001 00:34:35,190 --> 00:34:33,359 so we're looking on the horizontal axis 1002 00:34:37,270 --> 00:34:35,200 at the energy of the light 1003 00:34:38,310 --> 00:34:37,280 and on the vertical axis the brightness 1004 00:34:39,990 --> 00:34:38,320 of that light 1005 00:34:41,829 --> 00:34:40,000 and we can see here that we have this 1006 00:34:42,869 --> 00:34:41,839 emission line feature which is coming 1007 00:34:44,710 --> 00:34:42,879 from very close 1008 00:34:46,790 --> 00:34:44,720 to the supermassive black hole turns out 1009 00:34:48,389 --> 00:34:46,800 to be from iron k alpha very highly 1010 00:34:50,310 --> 00:34:48,399 ionized iron 1011 00:34:52,950 --> 00:34:50,320 and then we see here this absorption 1012 00:34:54,149 --> 00:34:52,960 feature and so with some very detailed 1013 00:34:56,069 --> 00:34:54,159 and careful modeling 1014 00:34:58,150 --> 00:34:56,079 we can figure out that this absorption 1015 00:34:59,829 --> 00:34:58,160 line is coming from the same excited 1016 00:35:02,550 --> 00:34:59,839 state as this emission line 1017 00:35:05,190 --> 00:35:02,560 and this corresponds to a very very 1018 00:35:06,870 --> 00:35:05,200 large shift a very large doppler shift 1019 00:35:08,790 --> 00:35:06,880 so as we talked about we can use those 1020 00:35:12,230 --> 00:35:08,800 shifts to determine the velocity 1021 00:35:14,630 --> 00:35:12,240 and in this case it works out to be 15 1022 00:35:16,470 --> 00:35:14,640 of the speed of light which is 1023 00:35:18,310 --> 00:35:16,480 absolutely insane 1024 00:35:20,550 --> 00:35:18,320 so by looking at more of these objects 1025 00:35:23,510 --> 00:35:20,560 we've found that ultra fast outflows 1026 00:35:24,390 --> 00:35:23,520 can move at up to 30 percent the speed 1027 00:35:27,430 --> 00:35:24,400 of light 1028 00:35:27,990 --> 00:35:27,440 that's something like 60 000 miles per 1029 00:35:31,030 --> 00:35:28,000 second 1030 00:35:32,390 --> 00:35:31,040 that is one serious speeding ticket so 1031 00:35:33,990 --> 00:35:32,400 what we're seeing is we have 1032 00:35:35,349 --> 00:35:34,000 this artist conception on the right with 1033 00:35:36,310 --> 00:35:35,359 the supermassive black hole in the 1034 00:35:38,069 --> 00:35:36,320 accretion disk 1035 00:35:39,670 --> 00:35:38,079 and this material is being launched from 1036 00:35:41,430 --> 00:35:39,680 very close to the accretion disk and 1037 00:35:42,550 --> 00:35:41,440 then it's absorbing some of the light as 1038 00:35:43,589 --> 00:35:42,560 it's moving 1039 00:35:46,150 --> 00:35:43,599 and that's what we see as that 1040 00:35:48,710 --> 00:35:46,160 absorption feature in the spectrum 1041 00:35:49,990 --> 00:35:48,720 another interesting feature of ufos is 1042 00:35:52,069 --> 00:35:50,000 that when we look at them 1043 00:35:53,349 --> 00:35:52,079 and we revisit the same galaxies we see 1044 00:35:55,430 --> 00:35:53,359 that they change 1045 00:35:56,630 --> 00:35:55,440 on time scales of months to years or 1046 00:35:58,150 --> 00:35:56,640 even faster 1047 00:36:00,470 --> 00:35:58,160 and so this is telling us that these are 1048 00:36:02,550 --> 00:36:00,480 not nice steady 1049 00:36:04,310 --> 00:36:02,560 constant types of phenomena but they're 1050 00:36:06,630 --> 00:36:04,320 very chaotic and tumultuous they're 1051 00:36:07,910 --> 00:36:06,640 constantly changing 1052 00:36:09,510 --> 00:36:07,920 and this could be really important 1053 00:36:10,550 --> 00:36:09,520 because we have gas that's moving very 1054 00:36:12,550 --> 00:36:10,560 very fast 1055 00:36:13,750 --> 00:36:12,560 and so it may actually be able to sweep 1056 00:36:16,069 --> 00:36:13,760 material out 1057 00:36:18,390 --> 00:36:16,079 and regulate how fast the black hole is 1058 00:36:20,710 --> 00:36:18,400 growing as the black hole is eating 1059 00:36:22,790 --> 00:36:20,720 it's actually generating the energy that 1060 00:36:24,550 --> 00:36:22,800 is pushing away its fuel it's pushing 1061 00:36:26,710 --> 00:36:24,560 away its supply of gas that it would 1062 00:36:29,109 --> 00:36:26,720 otherwise try to accrete 1063 00:36:30,710 --> 00:36:29,119 and so the question is well is there any 1064 00:36:31,910 --> 00:36:30,720 evidence that this is what's really 1065 00:36:34,710 --> 00:36:31,920 happening 1066 00:36:36,950 --> 00:36:34,720 and indeed there is so looking here on 1067 00:36:38,950 --> 00:36:36,960 the vertical axis we have the mass 1068 00:36:41,190 --> 00:36:38,960 of these supermassive black holes in 1069 00:36:44,470 --> 00:36:41,200 terms of mass of the sun moving from 1070 00:36:47,190 --> 00:36:44,480 a million to 10 billion and then we have 1071 00:36:49,109 --> 00:36:47,200 the mass of the bulge that large 1072 00:36:50,790 --> 00:36:49,119 semi-spherical distribution of stars 1073 00:36:53,270 --> 00:36:50,800 around the center of the galaxy 1074 00:36:54,790 --> 00:36:53,280 and the velocity of those stars and what 1075 00:36:56,230 --> 00:36:54,800 we can see is that these two things are 1076 00:36:57,430 --> 00:36:56,240 correlated meaning if we have a 1077 00:36:59,190 --> 00:36:57,440 measurement of one 1078 00:37:01,190 --> 00:36:59,200 then we have a reasonable estimate of 1079 00:37:02,310 --> 00:37:01,200 the other and now you might say well 1080 00:37:04,470 --> 00:37:02,320 that makes sense right 1081 00:37:05,910 --> 00:37:04,480 larger galaxy larger bulge larger 1082 00:37:07,750 --> 00:37:05,920 supermassive black hole 1083 00:37:09,750 --> 00:37:07,760 but there's no necessity for it to be 1084 00:37:11,349 --> 00:37:09,760 that way and what i mean is 1085 00:37:13,030 --> 00:37:11,359 that even though supermassive black 1086 00:37:14,790 --> 00:37:13,040 holes are so dense and have such a 1087 00:37:16,630 --> 00:37:14,800 strong gravitational pull 1088 00:37:17,990 --> 00:37:16,640 it's only when you get really close to 1089 00:37:18,790 --> 00:37:18,000 them that their gravity starts to 1090 00:37:20,710 --> 00:37:18,800 dominate 1091 00:37:22,390 --> 00:37:20,720 so within a galaxy the supermassive 1092 00:37:24,310 --> 00:37:22,400 black hole is only dominating the 1093 00:37:26,310 --> 00:37:24,320 gravity in a region maybe a few light 1094 00:37:27,990 --> 00:37:26,320 years or smaller around it 1095 00:37:30,069 --> 00:37:28,000 whereas the bulge of these galaxies is 1096 00:37:31,910 --> 00:37:30,079 on scales of thousands of light years 1097 00:37:33,109 --> 00:37:31,920 and so they're just not gravitationally 1098 00:37:34,630 --> 00:37:33,119 aware of each other 1099 00:37:36,470 --> 00:37:34,640 it's kind of like holding a magnet at a 1100 00:37:38,470 --> 00:37:36,480 paper clip a mile away the effect is 1101 00:37:40,230 --> 00:37:38,480 just too weak to really matter 1102 00:37:41,990 --> 00:37:40,240 and so this is one piece of evidence 1103 00:37:44,150 --> 00:37:42,000 that maybe these two 1104 00:37:45,670 --> 00:37:44,160 individual entities basically evolve 1105 00:37:47,270 --> 00:37:45,680 together maybe the black hole in the 1106 00:37:49,190 --> 00:37:47,280 bulge grew up together 1107 00:37:50,710 --> 00:37:49,200 exchanging energy and information 1108 00:37:52,710 --> 00:37:50,720 through these winds 1109 00:37:53,990 --> 00:37:52,720 and through this exchange of material 1110 00:37:56,310 --> 00:37:54,000 that's being pushed out 1111 00:37:58,069 --> 00:37:56,320 to larger radii that's not the only 1112 00:37:59,349 --> 00:37:58,079 interpretation of this result there are 1113 00:38:00,950 --> 00:37:59,359 other ways that you might be able to 1114 00:38:09,030 --> 00:38:00,960 generate this but this is one piece of 1115 00:38:12,630 --> 00:38:10,710 so the second stop on our tour of 1116 00:38:15,270 --> 00:38:12,640 supermassive black hole winds 1117 00:38:17,109 --> 00:38:15,280 is now looking within the galaxy bulge 1118 00:38:18,870 --> 00:38:17,119 so now we're looking on scales of a few 1119 00:38:21,510 --> 00:38:18,880 thousand light years 1120 00:38:22,630 --> 00:38:21,520 and so early studies in this uh regime 1121 00:38:24,710 --> 00:38:22,640 kind of showed that there were 1122 00:38:25,910 --> 00:38:24,720 non-rotational motions so it was clear 1123 00:38:28,230 --> 00:38:25,920 that gas was doing 1124 00:38:30,069 --> 00:38:28,240 something that wasn't just nice and 1125 00:38:31,910 --> 00:38:30,079 simple galaxy rotation 1126 00:38:33,829 --> 00:38:31,920 but it was really revolutionized with 1127 00:38:35,670 --> 00:38:33,839 data from the hubble space telescope 1128 00:38:36,710 --> 00:38:35,680 because as frank mentioned we get above 1129 00:38:39,510 --> 00:38:36,720 the atmosphere 1130 00:38:41,109 --> 00:38:39,520 we can see extremely small details and 1131 00:38:42,390 --> 00:38:41,119 the critical piece here is that this is 1132 00:38:44,150 --> 00:38:42,400 the first scale 1133 00:38:46,390 --> 00:38:44,160 as we move away from the black hole that 1134 00:38:47,910 --> 00:38:46,400 we can actually spatially resolve 1135 00:38:49,990 --> 00:38:47,920 meaning when we look at stars they're 1136 00:38:51,190 --> 00:38:50,000 infinitesimal small points of light 1137 00:38:53,190 --> 00:38:51,200 when you look at the moon and planets 1138 00:38:53,829 --> 00:38:53,200 they have a defined physical size on the 1139 00:38:55,829 --> 00:38:53,839 sky 1140 00:38:57,910 --> 00:38:55,839 and so we can actually resolve the 1141 00:38:59,829 --> 00:38:57,920 bulges of galaxies 1142 00:39:02,150 --> 00:38:59,839 so we're going to go ahead and start add 1143 00:39:05,270 --> 00:39:02,160 a galaxy and zoom in on its bulge 1144 00:39:07,190 --> 00:39:05,280 here's an example of ngc 4151 1145 00:39:09,349 --> 00:39:07,200 it's one of the most nearby and well 1146 00:39:10,870 --> 00:39:09,359 studied active galaxies because it is so 1147 00:39:12,950 --> 00:39:10,880 nearby and very bright 1148 00:39:15,589 --> 00:39:12,960 here we can see it has these extended 1149 00:39:17,990 --> 00:39:15,599 spiral arm structures it has this 1150 00:39:19,829 --> 00:39:18,000 ring of hot young stars that are forming 1151 00:39:21,910 --> 00:39:19,839 that are surrounding this yellowish 1152 00:39:23,670 --> 00:39:21,920 older bulge of stars 1153 00:39:25,670 --> 00:39:23,680 now this is an incredible ground-based 1154 00:39:27,190 --> 00:39:25,680 image but as frank mentioned again we're 1155 00:39:28,550 --> 00:39:27,200 just still limited by the earth's 1156 00:39:30,790 --> 00:39:28,560 atmosphere sometimes 1157 00:39:32,950 --> 00:39:30,800 so if we go ahead and zoom in with the 1158 00:39:36,310 --> 00:39:32,960 power of the hubble space telescope 1159 00:39:38,790 --> 00:39:36,320 we get a much clearer picture 1160 00:39:41,430 --> 00:39:38,800 now we can see individual clumps of 1161 00:39:44,150 --> 00:39:41,440 stars that are forming within the galaxy 1162 00:39:46,069 --> 00:39:44,160 we can see these dark spiral dust lanes 1163 00:39:48,230 --> 00:39:46,079 working their way into the center 1164 00:39:49,349 --> 00:39:48,240 around the bulge and we can start to see 1165 00:39:52,150 --> 00:39:49,359 some hint 1166 00:39:54,150 --> 00:39:52,160 of this bright active nucleus now like 1167 00:39:55,990 --> 00:39:54,160 any good criminal investigation show all 1168 00:39:57,109 --> 00:39:56,000 you have to do is hit your magic enhance 1169 00:39:58,310 --> 00:39:57,119 button again 1170 00:40:00,470 --> 00:39:58,320 okay of course it's not quite that 1171 00:40:03,270 --> 00:40:00,480 simple but if we zoom in once again 1172 00:40:04,150 --> 00:40:03,280 we get this incredible image of this 1173 00:40:06,950 --> 00:40:04,160 bulge scale 1174 00:40:08,790 --> 00:40:06,960 outflow produced by judy schmidt and so 1175 00:40:10,309 --> 00:40:08,800 down in the very center here we have 1176 00:40:12,630 --> 00:40:10,319 this supermassive black hole and 1177 00:40:14,870 --> 00:40:12,640 accretion disk our source of energy 1178 00:40:15,990 --> 00:40:14,880 and that radiation is traveling out into 1179 00:40:17,990 --> 00:40:16,000 the galaxy 1180 00:40:19,750 --> 00:40:18,000 it's exciting this gas it's making it 1181 00:40:22,390 --> 00:40:19,760 glow like a neon sign 1182 00:40:22,870 --> 00:40:22,400 and so we can see very clearly here that 1183 00:40:25,030 --> 00:40:22,880 there's an 1184 00:40:26,710 --> 00:40:25,040 impact on the galaxy but what is this 1185 00:40:28,390 --> 00:40:26,720 gas really doing how do we know where 1186 00:40:29,270 --> 00:40:28,400 it's going how do we know what its fate 1187 00:40:30,710 --> 00:40:29,280 is 1188 00:40:32,710 --> 00:40:30,720 and so of course the second piece to 1189 00:40:34,710 --> 00:40:32,720 that is by using spectroscopy 1190 00:40:36,470 --> 00:40:34,720 so if we isolate a portion of it using 1191 00:40:39,349 --> 00:40:36,480 the hubble space telescope looking at 1192 00:40:40,790 --> 00:40:39,359 just a specific portion of the galaxy 1193 00:40:42,550 --> 00:40:40,800 as we showed in some of our earlier 1194 00:40:43,990 --> 00:40:42,560 example spectra well if the gas was just 1195 00:40:45,589 --> 00:40:44,000 sitting there let's say we were looking 1196 00:40:46,150 --> 00:40:45,599 at two emission lines we might just 1197 00:40:48,870 --> 00:40:46,160 expect 1198 00:40:50,950 --> 00:40:48,880 nice straight lines galaxy is generally 1199 00:40:51,990 --> 00:40:50,960 rotating and so one side is moving 1200 00:40:53,910 --> 00:40:52,000 towards us another side 1201 00:40:55,829 --> 00:40:53,920 is moving away from us and so we'd 1202 00:40:58,309 --> 00:40:55,839 expect some sort of redshift and blue 1203 00:41:00,630 --> 00:40:58,319 shift on either side of the galaxy 1204 00:41:01,349 --> 00:41:00,640 when we look at the actual data for this 1205 00:41:03,349 --> 00:41:01,359 target 1206 00:41:05,349 --> 00:41:03,359 we see indeed some of the gas is 1207 00:41:07,349 --> 00:41:05,359 rotating but there's also this gas 1208 00:41:09,190 --> 00:41:07,359 moving at much higher velocities at 1209 00:41:11,270 --> 00:41:09,200 higher blue shifts and redshifts 1210 00:41:13,030 --> 00:41:11,280 so while the galaxy might be rotating at 1211 00:41:14,710 --> 00:41:13,040 a few hundred kilometers a second this 1212 00:41:16,630 --> 00:41:14,720 gas is moving at maybe a thousand 1213 00:41:18,950 --> 00:41:16,640 kilometers per second 1214 00:41:20,069 --> 00:41:18,960 so this is that clear signature that on 1215 00:41:21,829 --> 00:41:20,079 one side of galaxy 1216 00:41:24,630 --> 00:41:21,839 gas is moving towards you on the other 1217 00:41:27,270 --> 00:41:24,640 side gas is moving away from you 1218 00:41:27,670 --> 00:41:27,280 now this is an incredible result but 1219 00:41:29,670 --> 00:41:27,680 it's 1220 00:41:31,349 --> 00:41:29,680 kind of tough to picture the geometry 1221 00:41:32,950 --> 00:41:31,359 here what's really going on 1222 00:41:34,390 --> 00:41:32,960 so let's look at a model of this 1223 00:41:36,069 --> 00:41:34,400 starting down 1224 00:41:38,150 --> 00:41:36,079 right near the supermassive black hole 1225 00:41:40,309 --> 00:41:38,160 where all this radiation is coming out 1226 00:41:42,069 --> 00:41:40,319 and then let's zoom out onto scales of 1227 00:41:42,710 --> 00:41:42,079 the galaxy so we can see here we have 1228 00:41:45,270 --> 00:41:42,720 this blue 1229 00:41:46,309 --> 00:41:45,280 disk of the galaxy rotating around and 1230 00:41:48,790 --> 00:41:46,319 this radiation is 1231 00:41:50,950 --> 00:41:48,800 traveling out into the galaxy it's 1232 00:41:53,190 --> 00:41:50,960 exciting it's ionizing it and then it's 1233 00:41:54,710 --> 00:41:53,200 pushing it away from the supermassive 1234 00:41:56,309 --> 00:41:54,720 black hole 1235 00:41:57,829 --> 00:41:56,319 so this is an area of research that i've 1236 00:41:59,430 --> 00:41:57,839 been very interested in 1237 00:42:01,750 --> 00:41:59,440 and we've learned a number of things for 1238 00:42:02,550 --> 00:42:01,760 these types of supermassive black hole 1239 00:42:04,390 --> 00:42:02,560 winds 1240 00:42:05,589 --> 00:42:04,400 so the first is that the gas can 1241 00:42:07,030 --> 00:42:05,599 probably be launched 1242 00:42:08,790 --> 00:42:07,040 at a bunch of different distances 1243 00:42:10,630 --> 00:42:08,800 meaning it's not all coming from right 1244 00:42:12,950 --> 00:42:10,640 near the supermassive black hole 1245 00:42:14,550 --> 00:42:12,960 but as this radiation travels out it 1246 00:42:16,630 --> 00:42:14,560 sees the gas there it excites it and 1247 00:42:18,790 --> 00:42:16,640 then it starts pushing it 1248 00:42:20,710 --> 00:42:18,800 now while these are not moving nearly as 1249 00:42:22,309 --> 00:42:20,720 fast as the ultra fast outflows they're 1250 00:42:24,150 --> 00:42:22,319 moving at less than one percent of the 1251 00:42:25,750 --> 00:42:24,160 speed of light as compared to nearly 30 1252 00:42:27,430 --> 00:42:25,760 percent of the speed of light 1253 00:42:29,750 --> 00:42:27,440 because they're spatially resolved we 1254 00:42:30,710 --> 00:42:29,760 can work out how much material is there 1255 00:42:32,790 --> 00:42:30,720 in detail 1256 00:42:34,150 --> 00:42:32,800 and it turns out that these outflows can 1257 00:42:36,390 --> 00:42:34,160 carry several 1258 00:42:38,390 --> 00:42:36,400 million or even tens of millions of 1259 00:42:41,030 --> 00:42:38,400 solar masses worth of gas 1260 00:42:42,230 --> 00:42:41,040 it's a lot of material and so the impact 1261 00:42:44,390 --> 00:42:42,240 here is that this 1262 00:42:45,990 --> 00:42:44,400 may reduce star formation in the inner 1263 00:42:47,670 --> 00:42:46,000 regions of the galaxy because we're 1264 00:42:49,670 --> 00:42:47,680 evacuating the gas 1265 00:42:50,870 --> 00:42:49,680 which would otherwise be available to 1266 00:42:52,790 --> 00:42:50,880 form stars 1267 00:42:55,430 --> 00:42:52,800 in addition we're also heating that gas 1268 00:42:57,510 --> 00:42:55,440 up gas needs to start to cool down to 1269 00:42:58,790 --> 00:42:57,520 collapse under gravity in order to form 1270 00:43:00,630 --> 00:42:58,800 stars 1271 00:43:02,150 --> 00:43:00,640 now this is kind of a general picture 1272 00:43:03,670 --> 00:43:02,160 and it's not the case for every single 1273 00:43:05,910 --> 00:43:03,680 galaxy in some cases 1274 00:43:07,990 --> 00:43:05,920 gas is actually driven out impacts other 1275 00:43:10,069 --> 00:43:08,000 gas and then may trigger star formation 1276 00:43:11,750 --> 00:43:10,079 so it's not a one size fits all in terms 1277 00:43:12,710 --> 00:43:11,760 of what we see the impact of these 1278 00:43:14,309 --> 00:43:12,720 outflows being 1279 00:43:17,270 --> 00:43:14,319 but this is kind of a general picture 1280 00:43:21,109 --> 00:43:18,950 so with that we're ready to move to the 1281 00:43:23,190 --> 00:43:21,119 third out of four spatial scales of our 1282 00:43:24,710 --> 00:43:23,200 tour of supermassive black hole winds 1283 00:43:27,190 --> 00:43:24,720 and that is scales 1284 00:43:28,069 --> 00:43:27,200 of the galaxy stellar disk so these are 1285 00:43:31,270 --> 00:43:28,079 basically 1286 00:43:33,109 --> 00:43:31,280 on scales of the entire galaxy 1287 00:43:34,230 --> 00:43:33,119 now you might mention earlier might 1288 00:43:35,910 --> 00:43:34,240 remember from earlier that i mentioned 1289 00:43:37,349 --> 00:43:35,920 that the luminosity of these active 1290 00:43:39,430 --> 00:43:37,359 galaxies is a key 1291 00:43:41,910 --> 00:43:39,440 factor and so if we're looking for 1292 00:43:44,710 --> 00:43:41,920 outflows on the scales of galaxies 1293 00:43:46,470 --> 00:43:44,720 we generally need more luminous active 1294 00:43:48,710 --> 00:43:46,480 galaxies because we need more 1295 00:43:50,630 --> 00:43:48,720 energy to push gas at these large 1296 00:43:51,510 --> 00:43:50,640 distances and to push large amounts of 1297 00:43:53,990 --> 00:43:51,520 gas 1298 00:43:55,589 --> 00:43:54,000 and so this is more commonly observed 1299 00:43:57,030 --> 00:43:55,599 further back in the more distant 1300 00:43:58,950 --> 00:43:57,040 universe 1301 00:44:00,390 --> 00:43:58,960 and so studies of this type have been 1302 00:44:01,190 --> 00:44:00,400 done with a number of telescopes and 1303 00:44:04,950 --> 00:44:01,200 instruments 1304 00:44:06,950 --> 00:44:04,960 really revolutionized this is the 1305 00:44:09,030 --> 00:44:06,960 atacama large millimeter and sub 1306 00:44:10,470 --> 00:44:09,040 millimeter array or alma 1307 00:44:12,710 --> 00:44:10,480 and so that's shown on the right here 1308 00:44:15,030 --> 00:44:12,720 this is basically a series of radio 1309 00:44:16,870 --> 00:44:15,040 and millimeter dishes that are all 1310 00:44:18,150 --> 00:44:16,880 pointed at the same object 1311 00:44:19,990 --> 00:44:18,160 and we're basically taking the 1312 00:44:21,990 --> 00:44:20,000 information from each of them 1313 00:44:23,990 --> 00:44:22,000 and through a process of interferometry 1314 00:44:24,870 --> 00:44:24,000 or interference we're bringing that data 1315 00:44:27,589 --> 00:44:24,880 together 1316 00:44:28,710 --> 00:44:27,599 in order to get an image that is as good 1317 00:44:31,750 --> 00:44:28,720 as if we had one 1318 00:44:33,349 --> 00:44:31,760 ginormous dish as we saw earlier and so 1319 00:44:36,150 --> 00:44:33,359 in this case you can separate these 1320 00:44:38,390 --> 00:44:36,160 telescopes by up to 16 kilometers and so 1321 00:44:41,910 --> 00:44:38,400 we're getting an image as if we had one 1322 00:44:43,510 --> 00:44:41,920 massive telescope so let's go ahead and 1323 00:44:46,309 --> 00:44:43,520 look at one of these so 1324 00:44:48,069 --> 00:44:46,319 this is an example of a galaxy now it's 1325 00:44:50,150 --> 00:44:48,079 much more distant and so we don't get 1326 00:44:51,030 --> 00:44:50,160 that fine exquisite detail in the image 1327 00:44:52,950 --> 00:44:51,040 necessarily 1328 00:44:55,109 --> 00:44:52,960 but this is actually quite a large 1329 00:44:56,230 --> 00:44:55,119 galaxy we're looking at excited gas here 1330 00:44:58,870 --> 00:44:56,240 on the scales of 1331 00:44:59,990 --> 00:44:58,880 around 10 kiloparsecs or over 30 000 1332 00:45:01,829 --> 00:45:00,000 light years 1333 00:45:03,670 --> 00:45:01,839 and so what we see looking at these 1334 00:45:05,430 --> 00:45:03,680 galaxies that are further away 1335 00:45:08,069 --> 00:45:05,440 in this case it's looking back nearly 10 1336 00:45:11,109 --> 00:45:08,079 billion years to a red shift of two 1337 00:45:12,710 --> 00:45:11,119 is that it's not very simple to figure 1338 00:45:14,230 --> 00:45:12,720 out what's going on it's not just the 1339 00:45:16,309 --> 00:45:14,240 supermassive black hole 1340 00:45:17,750 --> 00:45:16,319 that's necessarily driving these this 1341 00:45:19,829 --> 00:45:17,760 these winds 1342 00:45:21,829 --> 00:45:19,839 and what we found out is that stars 1343 00:45:23,990 --> 00:45:21,839 actually make a very large contribution 1344 00:45:25,190 --> 00:45:24,000 sometimes the dominant contribution in 1345 00:45:26,470 --> 00:45:25,200 these galaxies 1346 00:45:28,550 --> 00:45:26,480 and so what that's happening is 1347 00:45:29,349 --> 00:45:28,560 basically stars are either forming very 1348 00:45:30,950 --> 00:45:29,359 rapidly 1349 00:45:33,270 --> 00:45:30,960 and their immense radiation is 1350 00:45:35,910 --> 00:45:33,280 contributing to driving these winds 1351 00:45:37,990 --> 00:45:35,920 or as stars die through powerful super 1352 00:45:39,910 --> 00:45:38,000 anova events that frank showed earlier 1353 00:45:41,349 --> 00:45:39,920 they emit an immense amount of radiation 1354 00:45:44,230 --> 00:45:41,359 that can also go ahead 1355 00:45:46,230 --> 00:45:44,240 and excite and move this gas so stellar 1356 00:45:47,750 --> 00:45:46,240 outflows and stellar winds are worthy of 1357 00:45:48,550 --> 00:45:47,760 an entire another talk in and of 1358 00:45:50,230 --> 00:45:48,560 themselves 1359 00:45:52,150 --> 00:45:50,240 so this is just to point out that 1360 00:45:53,430 --> 00:45:52,160 sometimes it's more than one mechanism 1361 00:45:55,510 --> 00:45:53,440 at work 1362 00:45:57,750 --> 00:45:55,520 and this is a key place where we'll 1363 00:45:58,950 --> 00:45:57,760 learn a lot more with the james webb 1364 00:46:00,790 --> 00:45:58,960 space telescope 1365 00:46:03,190 --> 00:46:00,800 because we'll be able to probe these 1366 00:46:04,710 --> 00:46:03,200 galaxies on very small scales 1367 00:46:06,790 --> 00:46:04,720 we'll be able to look at them in great 1368 00:46:08,550 --> 00:46:06,800 detail with high sensitivity 1369 00:46:11,349 --> 00:46:08,560 in different portions of the spectrum 1370 00:46:12,950 --> 00:46:11,359 than we can necessarily look at now 1371 00:46:14,470 --> 00:46:12,960 and so when we look at this galaxy in 1372 00:46:16,069 --> 00:46:14,480 this image 1373 00:46:17,910 --> 00:46:16,079 we can go ahead and take a spectrum of 1374 00:46:19,990 --> 00:46:17,920 it and we have this first strong 1375 00:46:22,150 --> 00:46:20,000 emission line which is basically just 1376 00:46:23,510 --> 00:46:22,160 from the rotation of the galaxy 1377 00:46:25,589 --> 00:46:23,520 and then we can see that we actually 1378 00:46:26,150 --> 00:46:25,599 have a second emission line right next 1379 00:46:27,829 --> 00:46:26,160 to it 1380 00:46:29,670 --> 00:46:27,839 which is coming from the same excited 1381 00:46:31,829 --> 00:46:29,680 state and this is gas that's 1382 00:46:33,510 --> 00:46:31,839 moving at several hundred kilometers per 1383 00:46:35,270 --> 00:46:33,520 second and if we look at where this 1384 00:46:37,190 --> 00:46:35,280 material is relative to the center of 1385 00:46:39,349 --> 00:46:37,200 the galaxy we see this big 1386 00:46:40,230 --> 00:46:39,359 redshifted blob of material that's being 1387 00:46:41,670 --> 00:46:40,240 blown out 1388 00:46:45,990 --> 00:46:41,680 from the center of the galaxy or for 1389 00:46:50,390 --> 00:46:47,990 so finally we've arrived at the last 1390 00:46:51,510 --> 00:46:50,400 stop on our tour of supermassive black 1391 00:46:54,150 --> 00:46:51,520 hole winds and this 1392 00:46:55,270 --> 00:46:54,160 is the circum galactic medium where the 1393 00:46:57,990 --> 00:46:55,280 scales around 1394 00:46:59,510 --> 00:46:58,000 galaxies themselves so here as i 1395 00:47:01,910 --> 00:46:59,520 mentioned there are basically two 1396 00:47:03,670 --> 00:47:01,920 forms of these outflows there are these 1397 00:47:05,030 --> 00:47:03,680 wide angle mass outflows and then there 1398 00:47:07,510 --> 00:47:05,040 are these narrow radio 1399 00:47:09,349 --> 00:47:07,520 jets and so in this case what we're 1400 00:47:11,910 --> 00:47:09,359 often looking at on scales bigger than 1401 00:47:13,910 --> 00:47:11,920 galaxies are these radio jets 1402 00:47:15,589 --> 00:47:13,920 so in this case the particles within 1403 00:47:17,910 --> 00:47:15,599 these jets can be moving 1404 00:47:18,790 --> 00:47:17,920 very very fast typically maybe half the 1405 00:47:21,750 --> 00:47:18,800 speed of light 1406 00:47:23,270 --> 00:47:21,760 but sometimes in excess of 99 percent 1407 00:47:25,750 --> 00:47:23,280 the speed of light these are some of the 1408 00:47:29,510 --> 00:47:25,760 fastest phenomenon in the universe 1409 00:47:31,670 --> 00:47:29,520 so these are extremely fast moving jets 1410 00:47:33,349 --> 00:47:31,680 now again these are often found in more 1411 00:47:34,150 --> 00:47:33,359 luminous and more powerful and often 1412 00:47:36,470 --> 00:47:34,160 more massive 1413 00:47:38,549 --> 00:47:36,480 active galaxies and so here on the right 1414 00:47:41,349 --> 00:47:38,559 is an example of centaurus a 1415 00:47:43,030 --> 00:47:41,359 which is a more nearby active galaxy 1416 00:47:45,109 --> 00:47:43,040 here we can see it has some bright 1417 00:47:45,990 --> 00:47:45,119 emission from stars it has a dust lane 1418 00:47:48,390 --> 00:47:46,000 across it 1419 00:47:49,589 --> 00:47:48,400 and if we zoom in and add in millimeter 1420 00:47:52,069 --> 00:47:49,599 radio data 1421 00:47:52,710 --> 00:47:52,079 we can see these powerful jets so we can 1422 00:47:54,870 --> 00:47:52,720 see these two 1423 00:47:57,109 --> 00:47:54,880 jets here which are pushing their way 1424 00:47:58,870 --> 00:47:57,119 out beyond the galaxy to scales larger 1425 00:48:00,390 --> 00:47:58,880 than the galaxy 1426 00:48:02,710 --> 00:48:00,400 now in this case this is a more nearby 1427 00:48:05,270 --> 00:48:02,720 example let's go to more powerful 1428 00:48:07,910 --> 00:48:05,280 examples in the more distant universe 1429 00:48:09,670 --> 00:48:07,920 in particular the impact of these jets 1430 00:48:11,589 --> 00:48:09,680 is most clearly seen when we look at 1431 00:48:13,750 --> 00:48:11,599 clusters and groups of galaxies where 1432 00:48:15,829 --> 00:48:13,760 they have something to interact with 1433 00:48:17,589 --> 00:48:15,839 so we're going to start out with a 1434 00:48:18,390 --> 00:48:17,599 hubble space telescope image in the 1435 00:48:20,309 --> 00:48:18,400 optical 1436 00:48:21,910 --> 00:48:20,319 and here we can see we have a large 1437 00:48:24,069 --> 00:48:21,920 galaxy in the center 1438 00:48:24,950 --> 00:48:24,079 we have a bunch of smaller galaxies 1439 00:48:26,710 --> 00:48:24,960 around it 1440 00:48:28,150 --> 00:48:26,720 but for the most part it just looks like 1441 00:48:30,390 --> 00:48:28,160 an image of galaxies 1442 00:48:31,510 --> 00:48:30,400 now we go ahead and add in the radio 1443 00:48:34,710 --> 00:48:31,520 information 1444 00:48:35,910 --> 00:48:34,720 in red we can see this long extended 1445 00:48:37,670 --> 00:48:35,920 radio jet 1446 00:48:40,150 --> 00:48:37,680 starting near the center of the galaxy 1447 00:48:41,910 --> 00:48:40,160 and then pushing its way out past 1448 00:48:43,190 --> 00:48:41,920 well beyond some of the galaxies in this 1449 00:48:44,870 --> 00:48:43,200 cluster 1450 00:48:47,430 --> 00:48:44,880 now even with these two pieces of 1451 00:48:48,230 --> 00:48:47,440 information we still can't fully see the 1452 00:48:50,790 --> 00:48:48,240 impact 1453 00:48:51,750 --> 00:48:50,800 until we add in information from the 1454 00:48:54,069 --> 00:48:51,760 x-rays 1455 00:48:56,150 --> 00:48:54,079 and so we add that information in blue 1456 00:48:57,990 --> 00:48:56,160 and put these all together 1457 00:49:00,630 --> 00:48:58,000 and we end up with an image that looks 1458 00:49:02,950 --> 00:49:00,640 like this and so what we're seeing here 1459 00:49:03,990 --> 00:49:02,960 is this radio jet is moving out away 1460 00:49:06,069 --> 00:49:04,000 from the galaxy 1461 00:49:07,990 --> 00:49:06,079 and it's actually carving out these kind 1462 00:49:11,910 --> 00:49:08,000 of bubbles in this very hot 1463 00:49:13,430 --> 00:49:11,920 tenuous x-ray gas so here is the 1464 00:49:15,349 --> 00:49:13,440 the overall view with these three 1465 00:49:16,309 --> 00:49:15,359 different energy and wavelength regimes 1466 00:49:19,430 --> 00:49:16,319 individually 1467 00:49:20,950 --> 00:49:19,440 and what we can learn from them combined 1468 00:49:23,430 --> 00:49:20,960 so the kind of the overall picture 1469 00:49:25,750 --> 00:49:23,440 that's emerging of these big massive 1470 00:49:27,990 --> 00:49:25,760 active galaxies with jets and clusters 1471 00:49:29,670 --> 00:49:28,000 is that the jet is acting to basically 1472 00:49:32,309 --> 00:49:29,680 prevent the gas from cooling 1473 00:49:33,990 --> 00:49:32,319 and falling into galaxies to form stars 1474 00:49:36,309 --> 00:49:34,000 so naturally the gas would want to cool 1475 00:49:37,910 --> 00:49:36,319 the gravity would pull it into galaxies 1476 00:49:39,750 --> 00:49:37,920 it should begin to form stars and so 1477 00:49:42,150 --> 00:49:39,760 this jet is basically keeping the gas 1478 00:49:43,990 --> 00:49:42,160 out there keeping it heating up and in 1479 00:49:46,950 --> 00:49:44,000 some cases it can reduce the rate at 1480 00:49:49,750 --> 00:49:46,960 which stars form by up to a factor of 10 1481 00:49:51,109 --> 00:49:49,760 so it's really quite powerful and this 1482 00:49:53,109 --> 00:49:51,119 is often denoted 1483 00:49:54,870 --> 00:49:53,119 maintenance mode outflows or maintenance 1484 00:49:56,630 --> 00:49:54,880 mode feedback basically as the 1485 00:49:58,309 --> 00:49:56,640 black hole is feeding and delivering 1486 00:50:01,190 --> 00:49:58,319 feedback to its environment 1487 00:50:02,710 --> 00:50:01,200 rather than actually pushing gas well 1488 00:50:03,030 --> 00:50:02,720 outside the galaxies we're basically 1489 00:50:05,109 --> 00:50:03,040 just 1490 00:50:06,790 --> 00:50:05,119 keeping it there and keeping it warm and 1491 00:50:10,309 --> 00:50:06,800 that way it can't collapse down 1492 00:50:12,710 --> 00:50:10,319 to form stars so with that 1493 00:50:14,470 --> 00:50:12,720 to kind of pull all of this together i 1494 00:50:15,589 --> 00:50:14,480 hope i've shown you that supermassive 1495 00:50:18,390 --> 00:50:15,599 black holes 1496 00:50:20,630 --> 00:50:18,400 and the agn that they power have the 1497 00:50:21,510 --> 00:50:20,640 potential to significantly impact their 1498 00:50:23,430 --> 00:50:21,520 galaxies 1499 00:50:25,109 --> 00:50:23,440 so this may be on scales of the 1500 00:50:26,950 --> 00:50:25,119 supermassive black hole 1501 00:50:28,710 --> 00:50:26,960 and the bulge of the galaxy with these 1502 00:50:31,109 --> 00:50:28,720 ultra fast outflows 1503 00:50:32,790 --> 00:50:31,119 it can be within the bulge and on the 1504 00:50:35,349 --> 00:50:32,800 scales of the galaxy disk 1505 00:50:37,349 --> 00:50:35,359 looking at the rates at which stars form 1506 00:50:38,390 --> 00:50:37,359 and it can be on even larger scales on 1507 00:50:40,790 --> 00:50:38,400 entire 1508 00:50:43,030 --> 00:50:40,800 groups and clusters of galaxies where 1509 00:50:45,349 --> 00:50:43,040 we're keeping lots of gas hot and moving 1510 00:50:48,230 --> 00:50:45,359 around so that way it can't form stars 1511 00:50:50,309 --> 00:50:48,240 and is impacting the overall formation 1512 00:50:52,069 --> 00:50:50,319 of galaxy structure 1513 00:50:54,069 --> 00:50:52,079 so i'd like to end by coming back to 1514 00:50:57,349 --> 00:50:54,079 where we started with this image 1515 00:50:59,430 --> 00:50:57,359 of ngc 1275 and i hope now that this 1516 00:51:01,349 --> 00:50:59,440 gives you a little more awe inspire 1517 00:51:03,430 --> 00:51:01,359 as it does to me what we have down in 1518 00:51:04,069 --> 00:51:03,440 the center is this supermassive black 1519 00:51:06,069 --> 00:51:04,079 hole 1520 00:51:07,589 --> 00:51:06,079 that's eating material and putting an 1521 00:51:10,630 --> 00:51:07,599 immense amount of radiation 1522 00:51:12,549 --> 00:51:10,640 out into the galaxy and beyond in this 1523 00:51:13,829 --> 00:51:12,559 case it's exciting that gas 1524 00:51:15,670 --> 00:51:13,839 it's pushing it away from the 1525 00:51:16,470 --> 00:51:15,680 supermassive black hole out beyond the 1526 00:51:18,069 --> 00:51:16,480 galaxy 1527 00:51:20,390 --> 00:51:18,079 and we can see even here that we're 1528 00:51:22,950 --> 00:51:20,400 lighting up gas within the cluster in 1529 00:51:24,950 --> 00:51:22,960 these long red filaments and strings 1530 00:51:26,950 --> 00:51:24,960 which contain millions and tens of 1531 00:51:27,750 --> 00:51:26,960 millions or even more solar masses worth 1532 00:51:30,230 --> 00:51:27,760 of gas 1533 00:51:32,710 --> 00:51:30,240 it's keeping it hot and it's impacting 1534 00:51:34,710 --> 00:51:32,720 the entire environment around it 1535 00:51:35,990 --> 00:51:34,720 so if there's one real takeaway here is 1536 00:51:38,790 --> 00:51:36,000 that the supermassive black 1537 00:51:39,190 --> 00:51:38,800 hole resides at the very center on the 1538 00:51:42,309 --> 00:51:39,200 very 1539 00:51:44,150 --> 00:51:42,319 smallest scales of galaxies and yet it 1540 00:51:47,030 --> 00:51:44,160 has the potential 1541 00:51:48,150 --> 00:51:47,040 to impact nearly every scale that we can 1542 00:51:50,710 --> 00:51:48,160 observe 1543 00:51:53,910 --> 00:51:50,720 and with that i would be happy to take 1544 00:51:56,950 --> 00:51:55,990 all right thank you mitchell that was 1545 00:51:59,270 --> 00:51:56,960 wonderful it was 1546 00:52:00,150 --> 00:51:59,280 great um especially the way that you 1547 00:52:02,549 --> 00:52:00,160 worked um 1548 00:52:03,349 --> 00:52:02,559 and got across the idea that it does 1549 00:52:06,549 --> 00:52:03,359 really go 1550 00:52:08,230 --> 00:52:06,559 from you know parsec scales and down to 1551 00:52:09,910 --> 00:52:08,240 the supermassive black hole is a parsec 1552 00:52:12,870 --> 00:52:09,920 scale object out 1553 00:52:13,990 --> 00:52:12,880 to millions of parsecs uh when you get 1554 00:52:17,190 --> 00:52:14,000 their giant radio 1555 00:52:17,990 --> 00:52:17,200 jets uh we had a lot of interesting 1556 00:52:20,230 --> 00:52:18,000 discussion 1557 00:52:21,750 --> 00:52:20,240 in the chat um but one of the things 1558 00:52:25,349 --> 00:52:21,760 that uh people talked about 1559 00:52:26,309 --> 00:52:25,359 was the correlation between the bulge 1560 00:52:31,270 --> 00:52:26,319 mass 1561 00:52:32,549 --> 00:52:31,280 and you sort of answered it a bit but 1562 00:52:34,870 --> 00:52:32,559 you know given that the 1563 00:52:35,589 --> 00:52:34,880 the formation time scale of the two that 1564 00:52:38,230 --> 00:52:35,599 obviously 1565 00:52:38,870 --> 00:52:38,240 means how quickly do they form and you 1566 00:52:41,510 --> 00:52:38,880 know 1567 00:52:43,670 --> 00:52:41,520 do do do they form in the same time 1568 00:52:45,430 --> 00:52:43,680 scale type thing 1569 00:52:46,790 --> 00:52:45,440 that's a great question so as i 1570 00:52:48,390 --> 00:52:46,800 mentioned when we look back at more 1571 00:52:49,030 --> 00:52:48,400 distant galaxies we're looking back in 1572 00:52:50,790 --> 00:52:49,040 time but 1573 00:52:52,549 --> 00:52:50,800 these are kind of snapshots so how does 1574 00:52:54,630 --> 00:52:52,559 this evolve over time 1575 00:52:56,470 --> 00:52:54,640 so in the very distant universe when 1576 00:52:57,349 --> 00:52:56,480 galaxies are basically just starting to 1577 00:52:59,510 --> 00:52:57,359 be built 1578 00:53:00,710 --> 00:52:59,520 that's when we have gas collapsing down 1579 00:53:04,870 --> 00:53:00,720 it's starting to form 1580 00:53:05,430 --> 00:53:04,880 that's when the bulge really begins to 1581 00:53:06,870 --> 00:53:05,440 form 1582 00:53:08,309 --> 00:53:06,880 and so it's really from the very 1583 00:53:10,309 --> 00:53:08,319 earliest portions of the universe where 1584 00:53:12,309 --> 00:53:10,319 we can see that supermassive black holes 1585 00:53:14,309 --> 00:53:12,319 and galaxies are beginning to form 1586 00:53:15,430 --> 00:53:14,319 that these energetic phenomena are 1587 00:53:17,270 --> 00:53:15,440 happening so 1588 00:53:18,630 --> 00:53:17,280 a important question is well how long 1589 00:53:20,870 --> 00:53:18,640 does it really take to 1590 00:53:22,230 --> 00:53:20,880 necessarily do this that's not a 1591 00:53:23,990 --> 00:53:22,240 question an answer a question that i 1592 00:53:25,910 --> 00:53:24,000 have a very sharp answer for but what i 1593 00:53:27,589 --> 00:53:25,920 can tell you is that it's time scales 1594 00:53:29,910 --> 00:53:27,599 on the order of millions of years or 1595 00:53:31,510 --> 00:53:29,920 more and so we get that basically from 1596 00:53:33,670 --> 00:53:31,520 looking at how long 1597 00:53:34,790 --> 00:53:33,680 active galaxies are basically turned on 1598 00:53:36,549 --> 00:53:34,800 for so 1599 00:53:37,910 --> 00:53:36,559 the majority of galaxies in the universe 1600 00:53:39,349 --> 00:53:37,920 are basically quiescent their black 1601 00:53:40,549 --> 00:53:39,359 holes are kind of hidden they're not 1602 00:53:42,309 --> 00:53:40,559 really eating 1603 00:53:44,150 --> 00:53:42,319 but by looking at lots and lots of 1604 00:53:46,069 --> 00:53:44,160 galaxies we can figure out that 1605 00:53:47,349 --> 00:53:46,079 almost every galaxy should become an 1606 00:53:49,109 --> 00:53:47,359 active galaxy for 1607 00:53:50,710 --> 00:53:49,119 maybe 10 percent of its life or 1608 00:53:52,390 --> 00:53:50,720 something on that order and so we're 1609 00:53:52,950 --> 00:53:52,400 talking about time scales of millions of 1610 00:53:55,910 --> 00:53:52,960 years 1611 00:53:56,870 --> 00:53:55,920 sometimes maybe a bit more for sure okay 1612 00:53:59,510 --> 00:53:56,880 great 1613 00:54:01,589 --> 00:53:59,520 um grant justice has been monitoring the 1614 00:54:03,190 --> 00:54:01,599 chat more than i've been able to 1615 00:54:05,190 --> 00:54:03,200 uh grant why don't you turn on your 1616 00:54:05,910 --> 00:54:05,200 video and join us and bring us some of 1617 00:54:08,870 --> 00:54:05,920 the 1618 00:54:10,950 --> 00:54:08,880 best questions from our chat sure 1619 00:54:13,030 --> 00:54:10,960 absolutely 1620 00:54:15,910 --> 00:54:13,040 so yes the chat has been very active for 1621 00:54:18,069 --> 00:54:15,920 this one black holes are always one of 1622 00:54:19,670 --> 00:54:18,079 both online and our favorite subjects 1623 00:54:22,390 --> 00:54:19,680 when we get it so 1624 00:54:25,270 --> 00:54:22,400 um the first one that i picked out was 1625 00:54:26,549 --> 00:54:25,280 is the length of the ultra fast outflows 1626 00:54:29,589 --> 00:54:26,559 an indication of 1627 00:54:31,910 --> 00:54:29,599 age or formation activation time for 1628 00:54:33,349 --> 00:54:31,920 black holes 1629 00:54:35,670 --> 00:54:33,359 uh that's a good question so basically 1630 00:54:37,589 --> 00:54:35,680 these ultra fast outflows are very very 1631 00:54:39,750 --> 00:54:37,599 close to the supermassive black hole 1632 00:54:40,630 --> 00:54:39,760 so we can't necessarily measure how far 1633 00:54:42,230 --> 00:54:40,640 they extend 1634 00:54:44,309 --> 00:54:42,240 but we can figure out how long they've 1635 00:54:45,510 --> 00:54:44,319 been there by looking at these galaxies 1636 00:54:48,630 --> 00:54:45,520 again and again 1637 00:54:50,549 --> 00:54:48,640 and so in that context often we see them 1638 00:54:52,309 --> 00:54:50,559 sometimes appearing and disappearing on 1639 00:54:53,990 --> 00:54:52,319 week or month time scales 1640 00:54:55,990 --> 00:54:54,000 but the real tricky part here this is 1641 00:54:57,750 --> 00:54:56,000 where things get almost kind of ghostly 1642 00:54:59,270 --> 00:54:57,760 is that sometimes they're appearing and 1643 00:55:00,950 --> 00:54:59,280 disappearing just because 1644 00:55:03,190 --> 00:55:00,960 we can't actually see them with our 1645 00:55:05,670 --> 00:55:03,200 x-ray telescopes and what i mean is 1646 00:55:07,190 --> 00:55:05,680 each type of telescope is is sensitive 1647 00:55:08,390 --> 00:55:07,200 to a different wavelength range a 1648 00:55:10,549 --> 00:55:08,400 different energy range 1649 00:55:12,870 --> 00:55:10,559 and so if that outflow becomes so 1650 00:55:15,109 --> 00:55:12,880 incredibly ionized and excited 1651 00:55:16,549 --> 00:55:15,119 it may still be there but it disappears 1652 00:55:17,510 --> 00:55:16,559 from our telescope and we basically just 1653 00:55:19,109 --> 00:55:17,520 can't see it 1654 00:55:21,030 --> 00:55:19,119 or on the other side of that the outflow 1655 00:55:21,750 --> 00:55:21,040 can get so dense and mass loaded with 1656 00:55:23,190 --> 00:55:21,760 material 1657 00:55:25,030 --> 00:55:23,200 that it's basically blocking the view 1658 00:55:26,549 --> 00:55:25,040 all together and so 1659 00:55:28,549 --> 00:55:26,559 in terms of what these ultra fast 1660 00:55:30,309 --> 00:55:28,559 outflows do we know that they're close 1661 00:55:31,910 --> 00:55:30,319 to the center of galaxies but there's 1662 00:55:33,750 --> 00:55:31,920 actually been some recent evidence that 1663 00:55:35,910 --> 00:55:33,760 maybe they travel out further 1664 00:55:37,589 --> 00:55:35,920 and then they push gas on the scales of 1665 00:55:39,829 --> 00:55:37,599 galaxies on galactic scale so there 1666 00:55:41,510 --> 00:55:39,839 might be some interaction 1667 00:55:43,910 --> 00:55:41,520 okay and that brings up another question 1668 00:55:45,270 --> 00:55:43,920 that was sort of referenced is that 1669 00:55:47,270 --> 00:55:45,280 the you talk about the speed of the 1670 00:55:49,030 --> 00:55:47,280 ultra fast ones right the ufos 1671 00:55:51,190 --> 00:55:49,040 um and then you talked about the speed 1672 00:55:52,789 --> 00:55:51,200 of this the stellar disc scale ones 1673 00:55:54,390 --> 00:55:52,799 but the ones that go all the way up i 1674 00:55:56,950 --> 00:55:54,400 mean does speed 1675 00:55:57,910 --> 00:55:56,960 correlate to the distance away is it you 1676 00:55:59,589 --> 00:55:57,920 know 1677 00:56:01,750 --> 00:55:59,599 how much of it is just the density of 1678 00:56:04,069 --> 00:56:01,760 the material it gets to plow through 1679 00:56:06,309 --> 00:56:04,079 versus how much this is the speed of the 1680 00:56:08,069 --> 00:56:06,319 uh up flow 1681 00:56:09,670 --> 00:56:08,079 absolutely that's a great question so 1682 00:56:11,670 --> 00:56:09,680 yeah so for those kind of bulge scale 1683 00:56:13,030 --> 00:56:11,680 outflows and galaxy scale outflows we're 1684 00:56:15,270 --> 00:56:13,040 generally looking at you know a few 1685 00:56:16,069 --> 00:56:15,280 hundred to a few thousand kilometers per 1686 00:56:18,069 --> 00:56:16,079 second 1687 00:56:19,829 --> 00:56:18,079 and since we can spatially resolve them 1688 00:56:21,190 --> 00:56:19,839 we can actually kind of see how they 1689 00:56:23,589 --> 00:56:21,200 change as they move throughout the 1690 00:56:24,950 --> 00:56:23,599 galaxy and so in a lot of cases we'll 1691 00:56:26,950 --> 00:56:24,960 see that it basically looks like 1692 00:56:28,789 --> 00:56:26,960 the gas is moving faster and faster and 1693 00:56:30,789 --> 00:56:28,799 faster and then at some point 1694 00:56:31,990 --> 00:56:30,799 it turns over and begins to slow down 1695 00:56:33,589 --> 00:56:32,000 and slow down and so 1696 00:56:35,670 --> 00:56:33,599 there's kind of two interpretations 1697 00:56:37,589 --> 00:56:35,680 either the gas is being accelerated and 1698 00:56:39,349 --> 00:56:37,599 then decelerated because you're running 1699 00:56:41,589 --> 00:56:39,359 out of energy to push it 1700 00:56:43,270 --> 00:56:41,599 or that gas is being driven from 1701 00:56:43,990 --> 00:56:43,280 wherever it was in the galaxy and the 1702 00:56:45,990 --> 00:56:44,000 further away 1703 00:56:47,510 --> 00:56:46,000 you get you just have less radiation so 1704 00:56:49,670 --> 00:56:47,520 you can't push it as fast 1705 00:56:51,910 --> 00:56:49,680 so these definitely change in velocity 1706 00:56:55,030 --> 00:56:51,920 as you move throughout a galaxy 1707 00:56:58,549 --> 00:56:55,040 okay grant what's in what's up next 1708 00:57:01,109 --> 00:56:58,559 yeah um so next up is do supermassive 1709 00:57:02,549 --> 00:57:01,119 black holes always begin as stars 1710 00:57:04,309 --> 00:57:02,559 is there any other way that they can 1711 00:57:06,870 --> 00:57:04,319 form 1712 00:57:08,870 --> 00:57:06,880 that is an excellent question if i had a 1713 00:57:10,150 --> 00:57:08,880 full answer to that i'd probably have a 1714 00:57:12,470 --> 00:57:10,160 nobel prize 1715 00:57:13,750 --> 00:57:12,480 um so the further back we look in the 1716 00:57:15,270 --> 00:57:13,760 universe we still see 1717 00:57:17,190 --> 00:57:15,280 evidence of these supermassive black 1718 00:57:20,230 --> 00:57:17,200 holes and how they can possibly 1719 00:57:22,069 --> 00:57:20,240 form so quickly so early in the universe 1720 00:57:23,829 --> 00:57:22,079 is definitely still a mystery 1721 00:57:26,069 --> 00:57:23,839 and so this is one of those things there 1722 00:57:27,589 --> 00:57:26,079 are certainly many great ideas out there 1723 00:57:29,190 --> 00:57:27,599 it's been worked on for some time and 1724 00:57:30,950 --> 00:57:29,200 this is definitely one of the key 1725 00:57:33,670 --> 00:57:30,960 questions to push after with the james 1726 00:57:35,829 --> 00:57:33,680 webb space telescope 1727 00:57:37,109 --> 00:57:35,839 so the answer is we don't know but we're 1728 00:57:38,710 --> 00:57:37,119 going to find out 1729 00:57:41,910 --> 00:57:38,720 that is correct yes quintessential 1730 00:57:46,069 --> 00:57:44,630 what trade of black holes surprised or 1731 00:57:49,670 --> 00:57:46,079 surprises you 1732 00:57:52,390 --> 00:57:49,680 the most ah what an 1733 00:57:54,470 --> 00:57:52,400 interesting question what trait of 1734 00:57:55,349 --> 00:57:54,480 supermassive black holes surprises me 1735 00:57:57,190 --> 00:57:55,359 the most 1736 00:57:58,470 --> 00:57:57,200 i think the trait that surprises me the 1737 00:58:01,829 --> 00:57:58,480 most 1738 00:58:04,630 --> 00:58:01,839 is how we picture these as having this 1739 00:58:06,710 --> 00:58:04,640 immense gravitational field that just 1740 00:58:08,069 --> 00:58:06,720 eats everything around it which if you 1741 00:58:11,270 --> 00:58:08,079 get close to the black hole 1742 00:58:12,470 --> 00:58:11,280 is very true however if you're very far 1743 00:58:14,309 --> 00:58:12,480 from the black hole 1744 00:58:16,150 --> 00:58:14,319 it's basically the same gravity as you 1745 00:58:17,589 --> 00:58:16,160 might feel from a star or any other body 1746 00:58:18,230 --> 00:58:17,599 and so for example if you were to take 1747 00:58:19,990 --> 00:58:18,240 the sun 1748 00:58:21,910 --> 00:58:20,000 and pluck it out of the solar system and 1749 00:58:23,030 --> 00:58:21,920 put a black hole with the same mass 1750 00:58:25,589 --> 00:58:23,040 which would be very small 1751 00:58:27,030 --> 00:58:25,599 few kilometers in size for the most part 1752 00:58:28,710 --> 00:58:27,040 all the planets would just keep going on 1753 00:58:30,470 --> 00:58:28,720 in their orbits as they were 1754 00:58:31,750 --> 00:58:30,480 things very close like mercury might get 1755 00:58:33,990 --> 00:58:31,760 perturbed a little bit 1756 00:58:35,510 --> 00:58:34,000 but in general it's just a point source 1757 00:58:37,349 --> 00:58:35,520 of gravity and so that is one of the 1758 00:58:38,789 --> 00:58:37,359 most surprising things to me is that 1759 00:58:40,630 --> 00:58:38,799 they're not just these monsters eating 1760 00:58:42,150 --> 00:58:40,640 necessarily everything all around them 1761 00:58:44,390 --> 00:58:42,160 but once you get very close 1762 00:58:45,430 --> 00:58:44,400 things do you get very intense yeah 1763 00:58:46,870 --> 00:58:45,440 that's one of the 1764 00:58:48,549 --> 00:58:46,880 hardest things to get across to the 1765 00:58:51,109 --> 00:58:48,559 public because 1766 00:58:52,069 --> 00:58:51,119 mass media has created them as oh 1767 00:58:54,950 --> 00:58:52,079 they're sucking in 1768 00:58:55,990 --> 00:58:54,960 everything around it uh no black holes 1769 00:58:59,670 --> 00:58:56,000 don't suck guys 1770 00:59:02,630 --> 00:58:59,680 okay they're just gravitational entities 1771 00:59:02,950 --> 00:59:02,640 so it's uh it's and that we will we will 1772 00:59:04,710 --> 00:59:02,960 be 1773 00:59:06,390 --> 00:59:04,720 explaining that for the rest of our 1774 00:59:07,829 --> 00:59:06,400 careers unfortunately 1775 00:59:09,670 --> 00:59:07,839 it's less of a headline if it's not 1776 00:59:12,870 --> 00:59:09,680 trying to kill us all immediately 1777 00:59:16,829 --> 00:59:12,880 or impending doom so 1778 00:59:19,190 --> 00:59:16,839 but so is it possible for emissions to 1779 00:59:19,829 --> 00:59:19,200 restart because one of the theories that 1780 00:59:23,190 --> 00:59:19,839 you mentioned 1781 00:59:24,150 --> 00:59:23,200 was black holes having a potential to 1782 00:59:26,470 --> 00:59:24,160 freeze 1783 00:59:27,670 --> 00:59:26,480 as it were is it possible for emissions 1784 00:59:30,950 --> 00:59:27,680 to come from a 1785 00:59:32,230 --> 00:59:30,960 frozen black hole absolutely this is a 1786 00:59:34,309 --> 00:59:32,240 fantastic question 1787 00:59:35,750 --> 00:59:34,319 so thank you for bringing this up so in 1788 00:59:37,270 --> 00:59:35,760 this picture i've kind of painted the 1789 00:59:38,789 --> 00:59:37,280 active galaxy is basically just 1790 00:59:40,789 --> 00:59:38,799 continuously putting out 1791 00:59:42,150 --> 00:59:40,799 energy it's exciting this gas and 1792 00:59:44,710 --> 00:59:42,160 driving it but 1793 00:59:46,390 --> 00:59:44,720 that all relies on material getting down 1794 00:59:46,870 --> 00:59:46,400 into the black hole and so that can 1795 00:59:49,109 --> 00:59:46,880 happen 1796 00:59:51,270 --> 00:59:49,119 from gas just working its way in from 1797 00:59:51,750 --> 00:59:51,280 minor mergers where little galaxies come 1798 00:59:53,270 --> 00:59:51,760 in 1799 00:59:54,789 --> 00:59:53,280 and so it's possible for these active 1800 00:59:57,030 --> 00:59:54,799 galaxies basically to turn 1801 00:59:58,309 --> 00:59:57,040 on and off so we can look at an active 1802 00:59:59,670 --> 00:59:58,319 galaxy today 1803 01:00:01,829 --> 00:59:59,680 and say well there's barely anything 1804 01:00:03,750 --> 01:00:01,839 going on but if we look at the larger 1805 01:00:05,829 --> 01:00:03,760 scales we'll see these echoes these kind 1806 01:00:08,950 --> 01:00:05,839 of light echoes or these remnants 1807 01:00:09,990 --> 01:00:08,960 of much more excited gas at larger radii 1808 01:00:11,589 --> 01:00:10,000 that tells us 1809 01:00:13,990 --> 01:00:11,599 that at some point in the past the 1810 01:00:15,670 --> 01:00:14,000 active galaxy was much more powerful 1811 01:00:17,030 --> 01:00:15,680 and we've also seen the converse of that 1812 01:00:18,789 --> 01:00:17,040 where basically it looks like something 1813 01:00:20,630 --> 01:00:18,799 is restarting where we have this 1814 01:00:22,470 --> 01:00:20,640 old radio jet that's basically 1815 01:00:24,150 --> 01:00:22,480 dissipating and then a new jet 1816 01:00:28,789 --> 01:00:24,160 that is being launched much closer to 1817 01:00:32,309 --> 01:00:28,799 the black hole 1818 01:00:35,510 --> 01:00:32,319 all right so on the online questions 1819 01:00:40,309 --> 01:00:35,520 that's more or less where i had um 1820 01:00:42,630 --> 01:00:40,319 i'm checking to see if there are any um 1821 01:00:43,430 --> 01:00:42,640 and he came in during the uh yeah 1822 01:00:45,910 --> 01:00:43,440 there's one about 1823 01:00:46,710 --> 01:00:45,920 chemical makeup of the gas is the 1824 01:00:49,750 --> 01:00:46,720 chemical makeup 1825 01:00:50,950 --> 01:00:49,760 of gas similar among galaxies or is the 1826 01:00:52,630 --> 01:00:50,960 proportion of elements 1827 01:00:55,430 --> 01:00:52,640 significantly different different from 1828 01:00:58,390 --> 01:00:55,440 one galaxy to the next 1829 01:01:00,150 --> 01:00:58,400 a very interesting question so all the 1830 01:01:01,190 --> 01:01:00,160 gas and dust and stars in these galaxies 1831 01:01:02,230 --> 01:01:01,200 are made up of all the different 1832 01:01:04,710 --> 01:01:02,240 elements we can see 1833 01:01:06,309 --> 01:01:04,720 primarily hydrogen and helium but traces 1834 01:01:07,829 --> 01:01:06,319 of everything else such as carbon 1835 01:01:10,150 --> 01:01:07,839 nitrogen and oxygen 1836 01:01:11,910 --> 01:01:10,160 and so depending on which distance 1837 01:01:13,829 --> 01:01:11,920 you're looking at from the galaxy 1838 01:01:15,349 --> 01:01:13,839 those relative abundances of the 1839 01:01:17,270 --> 01:01:15,359 elements do change 1840 01:01:19,349 --> 01:01:17,280 and so often we see near the centers of 1841 01:01:21,670 --> 01:01:19,359 galaxies where stars have formed in the 1842 01:01:23,990 --> 01:01:21,680 past and they process that material 1843 01:01:25,670 --> 01:01:24,000 we have higher metallicity basically 1844 01:01:26,470 --> 01:01:25,680 elements that are heavier than hydrogen 1845 01:01:28,710 --> 01:01:26,480 helium 1846 01:01:30,789 --> 01:01:28,720 whereas at much larger distances we 1847 01:01:33,270 --> 01:01:30,799 might see much lower metallicity so we 1848 01:01:35,270 --> 01:01:33,280 have much less of those heavy elements 1849 01:01:36,870 --> 01:01:35,280 and this is another reason i didn't have 1850 01:01:37,990 --> 01:01:36,880 a chance to touch on as to why these 1851 01:01:40,069 --> 01:01:38,000 winds and outflows are so 1852 01:01:41,910 --> 01:01:40,079 important because then we're taking some 1853 01:01:44,150 --> 01:01:41,920 of that enriched material 1854 01:01:45,990 --> 01:01:44,160 and we're moving it out onto much larger 1855 01:01:47,270 --> 01:01:46,000 scales where it may not normally be and 1856 01:01:48,230 --> 01:01:47,280 so that's going to affect the way that 1857 01:01:52,230 --> 01:01:48,240 stars form 1858 01:01:54,309 --> 01:01:52,240 gas cools and all those sorts of details 1859 01:01:55,670 --> 01:01:54,319 okay i actually have a pretty good one 1860 01:01:56,309 --> 01:01:55,680 that just came in right now i'm gonna 1861 01:01:58,470 --> 01:01:56,319 say there's 1862 01:01:59,910 --> 01:01:58,480 that that's a good good last question 1863 01:02:03,270 --> 01:01:59,920 yep 1864 01:02:07,510 --> 01:02:03,280 do black holes die and if so 1865 01:02:11,029 --> 01:02:07,520 how do black holes die 1866 01:02:12,630 --> 01:02:11,039 so theoretically there is a process 1867 01:02:14,870 --> 01:02:12,640 known as hawking radiation where black 1868 01:02:16,230 --> 01:02:14,880 holes could very very very slowly 1869 01:02:18,230 --> 01:02:16,240 evaporate 1870 01:02:20,470 --> 01:02:18,240 for supermassive black holes the amount 1871 01:02:22,549 --> 01:02:20,480 of time that that would take is 1872 01:02:23,510 --> 01:02:22,559 many times longer than the age of the 1873 01:02:25,589 --> 01:02:23,520 universe 1874 01:02:26,710 --> 01:02:25,599 even for small black holes made from 1875 01:02:28,789 --> 01:02:26,720 smaller stars 1876 01:02:30,309 --> 01:02:28,799 it's still an exceedingly long time and 1877 01:02:32,870 --> 01:02:30,319 so we don't have any direct 1878 01:02:34,470 --> 01:02:32,880 measurement of that but otherwise in 1879 01:02:36,630 --> 01:02:34,480 theory the black hole will just 1880 01:02:40,230 --> 01:02:36,640 sit there forever until something comes 1881 01:02:45,349 --> 01:02:43,510 ah well yeah black holes will 1882 01:02:46,829 --> 01:02:45,359 for at least for as far as we're 1883 01:02:48,470 --> 01:02:46,839 concerned black holes will be around 1884 01:02:51,109 --> 01:02:48,480 forever 1885 01:02:52,870 --> 01:02:51,119 and i probably think at least for my 1886 01:02:53,750 --> 01:02:52,880 lifetime will continually be learning 1887 01:02:56,710 --> 01:02:53,760 about them 1888 01:02:58,870 --> 01:02:56,720 uh there's just uh yeah the the amount 1889 01:03:00,789 --> 01:02:58,880 that radio astronomy and telescopes like 1890 01:03:03,190 --> 01:03:00,799 arecibo we talked about earlier 1891 01:03:04,630 --> 01:03:03,200 have contributed to our understanding of 1892 01:03:06,309 --> 01:03:04,640 what goes on in the cores of these 1893 01:03:09,190 --> 01:03:06,319 galaxies it's just been 1894 01:03:09,990 --> 01:03:09,200 amazing to watch over the decades 1895 01:03:11,829 --> 01:03:10,000 absolutely we've 1896 01:03:13,109 --> 01:03:11,839 learned so much and yet we still have so 1897 01:03:14,870 --> 01:03:13,119 much to learn and so 1898 01:03:16,230 --> 01:03:14,880 if we knew it all then astronomy would 1899 01:03:17,910 --> 01:03:16,240 not be fun and so that's one of the most 1900 01:03:19,600 --> 01:03:17,920 exciting things in astronomy 1901 01:03:19,700 --> 01:03:19,610 we knew it all we'd be out of jobs 1902 01:03:22,630 --> 01:03:19,710 [Music] 1903 01:03:24,309 --> 01:03:22,640 [Laughter] 1904 01:03:25,670 --> 01:03:24,319 to see as well like hubble's the same 1905 01:03:28,470 --> 01:03:25,680 age as i am so 1906 01:03:30,630 --> 01:03:28,480 we have the same lifespan thus far i 1907 01:03:31,589 --> 01:03:30,640 can't wait for jwst to get into some of 1908 01:03:32,950 --> 01:03:31,599 these 1909 01:03:34,950 --> 01:03:32,960 i didn't want to mention it during the 1910 01:03:37,349 --> 01:03:34,960 news summary but arecibo 1911 01:03:39,190 --> 01:03:37,359 was launched it was what started 1912 01:03:41,349 --> 01:03:39,200 operation the year i was born 1913 01:03:46,470 --> 01:03:41,359 um so it looks like i have a little bit 1914 01:03:50,309 --> 01:03:48,309 all right well thank you very much 1915 01:03:51,910 --> 01:03:50,319 appreciate all of your help 1916 01:03:53,829 --> 01:03:51,920 grant in getting the comments out of 1917 01:03:57,109 --> 01:03:53,839 this everybody next month 1918 01:03:59,190 --> 01:03:57,119 remember it's january 19th special date 1919 01:04:02,230 --> 01:03:59,200 we're skipping the first couple tuesdays 1920 01:04:05,510 --> 01:04:02,240 uh for for various reasons it will be 1921 01:04:08,549 --> 01:04:05,520 the darkest secrets of the universe 1922 01:04:10,470 --> 01:04:08,559 raja kuhatukurta from the uc santa cruz 1923 01:04:11,589 --> 01:04:10,480 we'll see you then thank you all for