1 00:00:08,720 --> 00:00:06,950 hello everybody and welcome to this 2 00:00:10,520 --> 00:00:08,730 week's Hubbell hangout my name is Tony 3 00:00:12,770 --> 00:00:10,530 Darnell and I work at the Space 4 00:00:16,129 --> 00:00:12,780 Telescope Science Institute and today we 5 00:00:18,529 --> 00:00:16,139 have another always awesome hangout plan 6 00:00:20,840 --> 00:00:18,539 for you today it turns out that the 7 00:00:22,849 --> 00:00:20,850 Milky Way has these very strange lobes 8 00:00:24,859 --> 00:00:22,859 on either side of it and astronomers 9 00:00:26,420 --> 00:00:24,869 using Hubble have have actually been 10 00:00:29,419 --> 00:00:26,430 able to measure some of the properties 11 00:00:30,679 --> 00:00:29,429 of these lobes using a quasar and we're 12 00:00:32,060 --> 00:00:30,689 going to talk about some of the details 13 00:00:33,650 --> 00:00:32,070 with that today with one of the 14 00:00:36,440 --> 00:00:33,660 astronomers here but before I get to the 15 00:00:37,850 --> 00:00:36,450 introductions let me tell you well let 16 00:00:40,400 --> 00:00:37,860 me first of all let me welcome my 17 00:00:42,470 --> 00:00:40,410 cohorts with me as always is dr. Carol 18 00:00:46,100 --> 00:00:42,480 Christian she's the outreach scientist 19 00:00:48,229 --> 00:00:46,110 for Hubble hi Carol and Scott Lewis the 20 00:00:50,569 --> 00:00:48,239 driver oh the Internet's extraordinaire 21 00:00:57,250 --> 00:00:50,579 hi Scott extraordinaire I like it's 22 00:01:00,799 --> 00:00:57,260 getting longer I lined up the third yeah 23 00:01:02,299 --> 00:01:00,809 so so we'd like to get your comments and 24 00:01:03,860 --> 00:01:02,309 questions throughout the Hangout if you 25 00:01:05,329 --> 00:01:03,870 are so inclined you can do that in a 26 00:01:07,609 --> 00:01:05,339 number of ways the easiest and my 27 00:01:09,950 --> 00:01:07,619 favorite way is to use the Q&A app but 28 00:01:12,770 --> 00:01:09,960 you can also comment on the event page 29 00:01:15,080 --> 00:01:12,780 in Google+ that we are broadcasting from 30 00:01:16,550 --> 00:01:15,090 as well as the YouTube page we're 31 00:01:21,260 --> 00:01:16,560 looking at all of those comments as well 32 00:01:24,890 --> 00:01:21,270 and so and finally on Twitter if you use 33 00:01:26,420 --> 00:01:24,900 the Hangout Hubble hangout Scott will be 34 00:01:27,980 --> 00:01:26,430 monitoring that and letting me know if 35 00:01:29,539 --> 00:01:27,990 there's any good tweets or comments that 36 00:01:31,160 --> 00:01:29,549 way and we will read them out as they 37 00:01:34,580 --> 00:01:31,170 come or toward the end so please 38 00:01:37,609 --> 00:01:34,590 interact with us so joining me today is 39 00:01:39,620 --> 00:01:37,619 an astronomer from these also from the 40 00:01:43,069 --> 00:01:39,630 Space Telescope Science Institute dr. 41 00:01:44,569 --> 00:01:43,079 Andy Fox hi Andy hi Tony hey ding I'm 42 00:01:47,300 --> 00:01:44,579 good thank you thank you for taking time 43 00:01:49,310 --> 00:01:47,310 out to join us so you've made some 44 00:01:52,190 --> 00:01:49,320 pretty interesting measurements for us 45 00:01:54,800 --> 00:01:52,200 using Hubble you have pointed it at a 46 00:01:57,469 --> 00:01:54,810 quasar that just so happened to be in a 47 00:02:00,410 --> 00:01:57,479 good spot to measure these very strange 48 00:02:04,219 --> 00:02:00,420 things that I I guess only until only 49 00:02:05,990 --> 00:02:04,229 recently have been discovered these 50 00:02:08,690 --> 00:02:06,000 features of our galaxy these strange 51 00:02:11,420 --> 00:02:08,700 kind of lobe things correct that is 52 00:02:13,620 --> 00:02:11,430 right in fact these lobes are called the 53 00:02:17,250 --> 00:02:13,630 Fermi bubbles were only discovered in 54 00:02:20,040 --> 00:02:17,260 20:10 in their gamma-ray emission by a 55 00:02:21,990 --> 00:02:20,050 satellite that NASA operates called the 56 00:02:23,730 --> 00:02:22,000 Fermi satellite so really only in the 57 00:02:26,760 --> 00:02:23,740 last five years have we known about this 58 00:02:29,040 --> 00:02:26,770 new component of our galaxy and we were 59 00:02:31,370 --> 00:02:29,050 able to use Hubble tour to measure how 60 00:02:34,470 --> 00:02:31,380 fast the gas was moving into these lobes 61 00:02:36,480 --> 00:02:34,480 what that gas is composed of in terms of 62 00:02:37,770 --> 00:02:36,490 its chemical elements and this was the 63 00:02:39,200 --> 00:02:37,780 first time we were able to really nail 64 00:02:42,180 --> 00:02:39,210 down some of these properties 65 00:02:43,350 --> 00:02:42,190 well it's awesome and I want to get to 66 00:02:44,610 --> 00:02:43,360 those measurements in just a minute but 67 00:02:47,570 --> 00:02:44,620 Scott can you put up that diagram that 68 00:02:50,820 --> 00:02:47,580 shows the Fermi bubbles for me bubbles 69 00:02:52,590 --> 00:02:50,830 doo-doo-doo sorry all right so here's 70 00:02:56,190 --> 00:02:52,600 what they look like or at least this is 71 00:02:58,770 --> 00:02:56,200 a artist impression of what they look 72 00:03:01,800 --> 00:02:58,780 like correct that is right so what you 73 00:03:03,630 --> 00:03:01,810 can see here is the disk of our Milky 74 00:03:05,250 --> 00:03:03,640 Way this is a side-on view of what our 75 00:03:07,980 --> 00:03:05,260 galaxy would look like from someone 76 00:03:10,290 --> 00:03:07,990 sitting outside the disk of the galaxy 77 00:03:13,590 --> 00:03:10,300 comes across at a diagonal there and 78 00:03:16,230 --> 00:03:13,600 those two purple lobes are centered on 79 00:03:21,060 --> 00:03:16,240 the the core of the galaxy in the center 80 00:03:23,670 --> 00:03:21,070 of the Milky Way you can see there is a 81 00:03:26,520 --> 00:03:23,680 lot of emission along the base of the 82 00:03:28,410 --> 00:03:26,530 lobes as you get closest to the center 83 00:03:30,810 --> 00:03:28,420 of the galaxy and these things they're 84 00:03:32,220 --> 00:03:30,820 really emitting light all across the 85 00:03:34,260 --> 00:03:32,230 electromagnetic spectrum they were 86 00:03:37,020 --> 00:03:34,270 discovered in gamma rays it turns out 87 00:03:39,840 --> 00:03:37,030 they also emit x-rays being microwaves 88 00:03:41,640 --> 00:03:39,850 and radio waves so they've started to be 89 00:03:43,949 --> 00:03:41,650 studied all these different wavelengths 90 00:03:45,390 --> 00:03:43,959 and we're piecing together the 91 00:03:46,530 --> 00:03:45,400 information we're getting from those 92 00:03:48,000 --> 00:03:46,540 different wavelengths to try and 93 00:03:50,370 --> 00:03:48,010 understand where they come from what 94 00:03:52,230 --> 00:03:50,380 they're doing so you see as you said at 95 00:03:54,030 --> 00:03:52,240 the beginning this is we've known about 96 00:03:56,760 --> 00:03:54,040 these for about five years obviously 97 00:03:59,340 --> 00:03:56,770 this is a vantage point that sadly we 98 00:04:01,820 --> 00:03:59,350 can never observe these things from but 99 00:04:05,190 --> 00:04:01,830 we do have you do have some of the 100 00:04:07,560 --> 00:04:05,200 images of the of these bubbles in the 101 00:04:12,030 --> 00:04:07,570 Fermi data correct that is absolutely 102 00:04:14,070 --> 00:04:12,040 right okay in in the Fermi data you 103 00:04:17,449 --> 00:04:14,080 certainly see these two lobes they look 104 00:04:20,420 --> 00:04:17,459 like balloons so can you put those up 105 00:04:23,190 --> 00:04:20,430 above and below the center of the galaxy 106 00:04:23,610 --> 00:04:23,200 I'll just wait for those to come up yeah 107 00:04:26,340 --> 00:04:23,620 here we are 108 00:04:27,930 --> 00:04:26,350 thanks god this is uh so this is an 109 00:04:31,020 --> 00:04:27,940 all-sky map 110 00:04:31,530 --> 00:04:31,030 it shows the full night sky just as we 111 00:04:33,330 --> 00:04:31,540 used to 112 00:04:35,370 --> 00:04:33,340 projecting you know there's the surface 113 00:04:37,530 --> 00:04:35,380 of the earth onto a map we do the same 114 00:04:40,380 --> 00:04:37,540 thing in so-called galactic coordinates 115 00:04:42,300 --> 00:04:40,390 and you can see right across the middle 116 00:04:44,430 --> 00:04:42,310 of this map that's what we call the 117 00:04:46,320 --> 00:04:44,440 Galactic equator that's the disk of the 118 00:04:48,120 --> 00:04:46,330 galaxy where almost all the stars in our 119 00:04:50,070 --> 00:04:48,130 galaxy are located is in that disk 120 00:04:51,810 --> 00:04:50,080 that's that bright band that's this is 121 00:04:53,850 --> 00:04:51,820 right bad okay so let's talk a little 122 00:04:55,530 --> 00:04:53,860 bit about where is Fermi I'll at when 123 00:04:57,840 --> 00:04:55,540 it's taking is it is it in orbit above 124 00:04:59,760 --> 00:04:57,850 Earth is it somewhere in the solar it 125 00:05:01,590 --> 00:04:59,770 says somewhere relatively close to Earth 126 00:05:03,000 --> 00:05:01,600 correct very close - that's right so 127 00:05:04,740 --> 00:05:03,010 it's in it's in orbit around the Earth 128 00:05:08,880 --> 00:05:04,750 very similar to the way that Hubble is 129 00:05:12,030 --> 00:05:08,890 okay so this is the the image you get 130 00:05:14,670 --> 00:05:12,040 basically looking from the earth and if 131 00:05:16,440 --> 00:05:14,680 it's this map is centered so that if you 132 00:05:18,540 --> 00:05:16,450 look towards the galactic center that's 133 00:05:22,350 --> 00:05:18,550 right in the center here of the image 134 00:05:24,720 --> 00:05:22,360 and you see there's two orange red lobes 135 00:05:25,890 --> 00:05:24,730 going out to either side what we call 136 00:05:28,320 --> 00:05:25,900 the northern hemisphere in a Sun 137 00:05:29,880 --> 00:05:28,330 hemisphere of the galaxy they're not 138 00:05:31,830 --> 00:05:29,890 quite symmetric there's a little bit 139 00:05:34,620 --> 00:05:31,840 more of the emission in the north and in 140 00:05:38,010 --> 00:05:34,630 the south but you do see the the same 141 00:05:40,860 --> 00:05:38,020 height extending into the into the halo 142 00:05:42,510 --> 00:05:40,870 of the galaxy in both sides and this is 143 00:05:45,090 --> 00:05:42,520 the raw data there was actually 144 00:05:49,620 --> 00:05:45,100 discovered from that Fermi satellite 145 00:05:52,920 --> 00:05:49,630 that it led to people dubbing them the 146 00:05:54,420 --> 00:05:52,930 Fermi bubbles yeah so these were so 147 00:05:57,120 --> 00:05:54,430 these were first observed in gamma rays 148 00:05:59,550 --> 00:05:57,130 and this is what our sky looks like in 149 00:06:01,860 --> 00:05:59,560 gamma rays there's also so the disk 150 00:06:04,980 --> 00:06:01,870 itself is very bright you see a lot of 151 00:06:07,740 --> 00:06:04,990 lot of photons there one of the colors 152 00:06:10,920 --> 00:06:07,750 mean well it's colored it's color-coded 153 00:06:12,360 --> 00:06:10,930 by the intensity by how bright in gamma 154 00:06:15,380 --> 00:06:12,370 rays it is but I should point out that 155 00:06:18,659 --> 00:06:15,390 the disk here they've actually 156 00:06:20,460 --> 00:06:18,669 subtracted off the contribution from the 157 00:06:25,770 --> 00:06:20,470 disk because the disk is glowing in 158 00:06:27,510 --> 00:06:25,780 gamma rays much brighter than the Fermi 159 00:06:30,240 --> 00:06:27,520 levels and the Sun they're smaller 160 00:06:32,130 --> 00:06:30,250 oh so in order to see it at all you had 161 00:06:33,659 --> 00:06:32,140 you have to subtract all that out you 162 00:06:36,469 --> 00:06:33,669 have to subtract off the disk and that 163 00:06:39,300 --> 00:06:36,479 is actually quite a complicated process 164 00:06:40,860 --> 00:06:39,310 this is a this is a cleaned up map that 165 00:06:45,450 --> 00:06:40,870 you're seeing right here 166 00:06:47,100 --> 00:06:45,460 which brings out the size is that why 167 00:06:48,749 --> 00:06:47,110 those are those those black areas there 168 00:06:51,179 --> 00:06:48,759 is that did that come out of the indi 169 00:06:53,070 --> 00:06:51,189 subtraction that's right yes okay all 170 00:06:55,170 --> 00:06:53,080 right please you subtracted out the 171 00:06:57,779 --> 00:06:55,180 contribution of the disk because it's so 172 00:06:59,249 --> 00:06:57,789 bright and gamma rays that you can't see 173 00:07:02,129 --> 00:06:59,259 these lobes now you can see the lobes 174 00:07:05,360 --> 00:07:02,139 and what we have is we can see kind of a 175 00:07:08,040 --> 00:07:05,370 little map of our own all-sky map of the 176 00:07:10,860 --> 00:07:08,050 of gamma and gamma rays are these other 177 00:07:13,439 --> 00:07:10,870 features like the ones that are like in 178 00:07:16,200 --> 00:07:13,449 the upper right part of the lobe there 179 00:07:18,300 --> 00:07:16,210 is is that part of our galaxy or is that 180 00:07:21,209 --> 00:07:18,310 background sky is that part of the lobes 181 00:07:23,219 --> 00:07:21,219 how do you know well it's very hard to 182 00:07:25,170 --> 00:07:23,229 know and actually that's so that's an 183 00:07:27,089 --> 00:07:25,180 open question you as you see as you go 184 00:07:29,459 --> 00:07:27,099 up into the northern Fermi bubble you 185 00:07:32,040 --> 00:07:29,469 keep going to the north you do see that 186 00:07:33,809 --> 00:07:32,050 oranjee region and that some of that may 187 00:07:35,820 --> 00:07:33,819 be associated physically with the Fermi 188 00:07:36,390 --> 00:07:35,830 bubbles but some of it could be in the 189 00:07:38,459 --> 00:07:36,400 foreground 190 00:07:40,860 --> 00:07:38,469 I mean there are spiral arms of our 191 00:07:43,040 --> 00:07:40,870 galaxy between us and a galactic center 192 00:07:46,170 --> 00:07:43,050 and those spiral arms can blow up 193 00:07:48,330 --> 00:07:46,180 material it can blow gas us into the 194 00:07:50,369 --> 00:07:48,340 halo which can also end up giving you X 195 00:07:52,469 --> 00:07:50,379 where I mentioned gamma-ray emission so 196 00:07:56,279 --> 00:07:52,479 it's actually very hard to tell from a 197 00:07:57,600 --> 00:07:56,289 map like this what is very close to the 198 00:08:00,659 --> 00:07:57,610 galactic center and what is somewhere 199 00:08:02,879 --> 00:08:00,669 else we'll get into that's where the 200 00:08:05,670 --> 00:08:02,889 Hubble data is actually very useful 201 00:08:06,869 --> 00:08:05,680 because Hubble is able to look at this 202 00:08:09,360 --> 00:08:06,879 from a different perspective from a 203 00:08:10,769 --> 00:08:09,370 different angle with its different types 204 00:08:12,809 --> 00:08:10,779 of data and that can give you more 205 00:08:14,640 --> 00:08:12,819 information about where things are so 206 00:08:16,439 --> 00:08:14,650 based on this image all we know is where 207 00:08:19,649 --> 00:08:16,449 it's bright and gamma rays we don't know 208 00:08:22,170 --> 00:08:19,659 how far away it is or where you know any 209 00:08:24,240 --> 00:08:22,180 any location information you got it 210 00:08:26,219 --> 00:08:24,250 exactly all this is is total intensity 211 00:08:29,129 --> 00:08:26,229 so it's got to be careful with this 212 00:08:31,140 --> 00:08:29,139 alone what you really understand and 213 00:08:32,339 --> 00:08:31,150 what you don't okay you also took the is 214 00:08:34,310 --> 00:08:32,349 we also have images in other wavelengths 215 00:08:37,920 --> 00:08:34,320 don't we that's correct 216 00:08:40,230 --> 00:08:37,930 so I have a question so that loopy thing 217 00:08:43,649 --> 00:08:40,240 off to the left 218 00:08:45,569 --> 00:08:43,659 what are those loopy things do you have 219 00:08:47,550 --> 00:08:45,579 you figured out what those loops are are 220 00:08:54,850 --> 00:08:47,560 you talking about to the far left of the 221 00:09:01,310 --> 00:08:59,960 hi Jerry yes um again this could be this 222 00:09:03,560 --> 00:09:01,320 could be related to the southern 223 00:09:05,930 --> 00:09:03,570 fermi-level but it's not a definitive 224 00:09:07,940 --> 00:09:05,940 connection we don't know for sure though 225 00:09:10,250 --> 00:09:07,950 that the distance of the galactic center 226 00:09:14,000 --> 00:09:10,260 oh right right 227 00:09:15,470 --> 00:09:14,010 just very suggestive okay Thanks so we 228 00:09:17,060 --> 00:09:15,480 saw these things in gamma rays and then 229 00:09:18,410 --> 00:09:17,070 we looked at it in other wavelengths sky 230 00:09:20,440 --> 00:09:18,420 you want to put it up of another one up 231 00:09:22,790 --> 00:09:20,450 there we go what here we are in 232 00:09:24,079 --> 00:09:22,800 microwave and radio and it's real 233 00:09:26,150 --> 00:09:24,089 they're really bright in there too 234 00:09:29,630 --> 00:09:26,160 that's right now this is a microwave 235 00:09:30,829 --> 00:09:29,640 image and the sharp-eyed viewers looking 236 00:09:33,050 --> 00:09:30,839 at this will notice that this is 237 00:09:35,840 --> 00:09:33,060 actually from 2004 which is before the 238 00:09:39,680 --> 00:09:35,850 Fermi bubbles were formally discovered 239 00:09:45,019 --> 00:09:39,690 okay this is from a 2004 reason for that 240 00:09:46,850 --> 00:09:45,029 is there had been this this glow above 241 00:09:49,250 --> 00:09:46,860 and below the center of the galaxy and 242 00:09:52,400 --> 00:09:49,260 microwaves but no one was really sure 243 00:09:54,170 --> 00:09:52,410 whether that was a real signal or 244 00:09:56,540 --> 00:09:54,180 whether it was something to do with the 245 00:09:58,160 --> 00:09:56,550 way that you subtract the disk because 246 00:09:59,540 --> 00:09:58,170 just like with the last image you can 247 00:10:01,160 --> 00:09:59,550 see the black man in the middle here 248 00:10:03,110 --> 00:10:01,170 that's where the disk of our galaxy 249 00:10:07,190 --> 00:10:03,120 emits microwaves and that has to be 250 00:10:09,319 --> 00:10:07,200 subtracted off so there was a hint of 251 00:10:12,440 --> 00:10:09,329 something going on in the microwave data 252 00:10:14,840 --> 00:10:12,450 from 2004 but when the gamma ray data 253 00:10:17,300 --> 00:10:14,850 came out in 2010 then you know it was 254 00:10:18,710 --> 00:10:17,310 bright in the same regions we have the 255 00:10:20,990 --> 00:10:18,720 lobes both in the north in the south 256 00:10:23,090 --> 00:10:21,000 then because you're seeing the signal at 257 00:10:24,410 --> 00:10:23,100 totally different wavelengths people 258 00:10:26,750 --> 00:10:24,420 really believed it and you that that was 259 00:10:30,260 --> 00:10:26,760 a genuine structure that they had 260 00:10:32,230 --> 00:10:30,270 detected okay so these are since this is 261 00:10:34,490 --> 00:10:32,240 a relatively new discovery do we know 262 00:10:37,100 --> 00:10:34,500 anything else about we do we know why 263 00:10:40,940 --> 00:10:37,110 they're there I mean are these lobes a 264 00:10:43,040 --> 00:10:40,950 common occurrence in in galaxies so 265 00:10:45,019 --> 00:10:43,050 there's a - very good questions on the 266 00:10:49,670 --> 00:10:45,029 first one why they're there 267 00:10:51,949 --> 00:10:49,680 we have we have two basic ideas of where 268 00:10:54,139 --> 00:10:51,959 they are coming from and what is 269 00:10:55,430 --> 00:10:54,149 powering them and they're both to do 270 00:10:57,290 --> 00:10:55,440 with the center of the Milky Way because 271 00:10:59,540 --> 00:10:57,300 we know that the center of the galaxy is 272 00:11:01,220 --> 00:10:59,550 a very energetic place and we know 273 00:11:04,220 --> 00:11:01,230 there's a supermassive black hole there 274 00:11:06,380 --> 00:11:04,230 with a mass several million times as 275 00:11:07,190 --> 00:11:06,390 high as the sun's mass so one 276 00:11:09,320 --> 00:11:07,200 possibility 277 00:11:11,600 --> 00:11:09,330 is that that supermassive black hole at 278 00:11:13,760 --> 00:11:11,610 the center of our galaxy is accreting 279 00:11:16,010 --> 00:11:13,770 matter from its surroundings and after 280 00:11:18,260 --> 00:11:16,020 the gas accretes towards the black hole 281 00:11:21,380 --> 00:11:18,270 it gets ejected and blown out into the 282 00:11:24,800 --> 00:11:21,390 halo and that blow out can create these 283 00:11:26,060 --> 00:11:24,810 bubbles another possibility is but only 284 00:11:28,010 --> 00:11:26,070 when it's blowing out right because 285 00:11:30,440 --> 00:11:28,020 right now for example it's not really 286 00:11:31,970 --> 00:11:30,450 eating anything up so late so only when 287 00:11:34,160 --> 00:11:31,980 it's active yeah because we know that 288 00:11:35,540 --> 00:11:34,170 black holes have active phases or not 289 00:11:37,910 --> 00:11:35,550 active phases so if it's actively 290 00:11:41,180 --> 00:11:37,920 accreting gas then it would be driving 291 00:11:42,800 --> 00:11:41,190 stuff out into the halo if it's in a 292 00:11:46,100 --> 00:11:42,810 quiet phase it wouldn't be doing that so 293 00:11:48,770 --> 00:11:46,110 that's definitely a stop-start episodic 294 00:11:53,090 --> 00:11:48,780 type of event so that's the black hole 295 00:11:57,080 --> 00:11:53,100 theory the other idea is whether star 296 00:11:58,790 --> 00:11:57,090 formation can be driving these bubbles 297 00:12:01,280 --> 00:11:58,800 into the halo so when you get star 298 00:12:03,470 --> 00:12:01,290 formation happening at a very high rate 299 00:12:05,450 --> 00:12:03,480 in other words lots of stars forming 300 00:12:07,130 --> 00:12:05,460 lots of stars running out of fuel some 301 00:12:10,130 --> 00:12:07,140 of them will go will turn into supernova 302 00:12:11,720 --> 00:12:10,140 supernova can explode and drive gas out 303 00:12:13,820 --> 00:12:11,730 of the disk of the galaxy up into the 304 00:12:15,860 --> 00:12:13,830 halo and we know that there are a lot of 305 00:12:16,970 --> 00:12:15,870 very massive stars close to the center 306 00:12:19,400 --> 00:12:16,980 of the galaxy because they've been 307 00:12:20,870 --> 00:12:19,410 observed so it could be that there was 308 00:12:23,560 --> 00:12:20,880 massive stars near the center of the 309 00:12:28,100 --> 00:12:23,570 galaxy have been turning into supernovae 310 00:12:30,980 --> 00:12:28,110 blowing bubbles out into the into what 311 00:12:33,020 --> 00:12:30,990 is now called the Fermi bubble so the 312 00:12:35,060 --> 00:12:33,030 we're not sure which of those two it is 313 00:12:37,070 --> 00:12:35,070 that is actually dominating but most of 314 00:12:38,600 --> 00:12:37,080 the rapidstar are the the active star 315 00:12:41,060 --> 00:12:38,610 formation in our galaxy isn't it going 316 00:12:43,040 --> 00:12:41,070 on at the leading edges of the spiral 317 00:12:46,400 --> 00:12:43,050 arms mostly and or it is the center of 318 00:12:48,800 --> 00:12:46,410 the galaxy hi active activity in star 319 00:12:51,830 --> 00:12:48,810 burn it is there's a lot of starburst 320 00:12:53,720 --> 00:12:51,840 activity in the nucleus of the galaxy it 321 00:12:57,670 --> 00:12:53,730 just as there also is in the spiral arms 322 00:13:00,440 --> 00:12:57,680 as you say but if you look at how much 323 00:13:02,870 --> 00:13:00,450 how much deformation is going on like 324 00:13:05,420 --> 00:13:02,880 per unit area of the disk is very high 325 00:13:06,800 --> 00:13:05,430 near the center of the galaxy and that's 326 00:13:08,990 --> 00:13:06,810 that's the number that you want to be 327 00:13:11,120 --> 00:13:09,000 high to to be able to drive out of wind 328 00:13:14,110 --> 00:13:11,130 I think we have one more slide in 329 00:13:17,180 --> 00:13:14,120 another wavelength is that true actually 330 00:13:18,020 --> 00:13:17,190 it's just this one okay okay so I wanted 331 00:13:21,230 --> 00:13:18,030 to make sure I got all the wavelengths 332 00:13:23,030 --> 00:13:21,240 that we had so and again again the black 333 00:13:26,120 --> 00:13:23,040 fanta cost there is the subtraction of 334 00:13:27,800 --> 00:13:26,130 the disk of our galaxy in there this 335 00:13:30,410 --> 00:13:27,810 doesn't so that you can actually see 336 00:13:32,930 --> 00:13:30,420 these things because the the signal from 337 00:13:34,670 --> 00:13:32,940 the disk is so strong correct yes it's 338 00:13:36,500 --> 00:13:34,680 really a contrast thing because if you 339 00:13:37,910 --> 00:13:36,510 put on that disk emission it would be so 340 00:13:39,980 --> 00:13:37,920 bright that everything else in the 341 00:13:42,470 --> 00:13:39,990 background would be lost in a noise okay 342 00:13:43,940 --> 00:13:42,480 so I have it okay so I have a question 343 00:13:45,139 --> 00:13:43,950 from Seb dust bunny I'm gonna go ahead 344 00:13:46,610 --> 00:13:45,149 and read it it's a little bit ahead of 345 00:13:49,490 --> 00:13:46,620 where I wanted to be but he goes has 346 00:13:52,070 --> 00:13:49,500 evidence of these bubbles seen in other 347 00:13:54,260 --> 00:13:52,080 galaxies and does it require a side-on 348 00:13:56,720 --> 00:13:54,270 view so that one goes back to my 349 00:13:58,760 --> 00:13:56,730 question or how common are these do you 350 00:14:01,639 --> 00:13:58,770 have any sense of things been seen in 351 00:14:04,340 --> 00:14:01,649 other galaxies at all so as far as 352 00:14:07,519 --> 00:14:04,350 gamma-ray bubbles go the answer is no we 353 00:14:09,590 --> 00:14:07,529 don't have any cases of other galaxies 354 00:14:14,269 --> 00:14:09,600 where we've seen these the problem is 355 00:14:15,800 --> 00:14:14,279 that we're not sensitive to detecting a 356 00:14:17,480 --> 00:14:15,810 gamma-ray emission from other galaxies 357 00:14:19,310 --> 00:14:17,490 in other words the reason we're not 358 00:14:21,230 --> 00:14:19,320 seeing them is not necessarily that they 359 00:14:23,540 --> 00:14:21,240 don't exist but it's that the light 360 00:14:25,699 --> 00:14:23,550 would be so faint that our telescopes 361 00:14:27,650 --> 00:14:25,709 aren't able to detect it and say whether 362 00:14:29,120 --> 00:14:27,660 it's there or not so our gamma-ray 363 00:14:30,260 --> 00:14:29,130 telescopes aren't powerful enough that's 364 00:14:32,740 --> 00:14:30,270 what you're saying that's another way of 365 00:14:34,970 --> 00:14:32,750 saying it so the satellite is is 366 00:14:37,190 --> 00:14:34,980 sensitive enough that it can see these 367 00:14:38,600 --> 00:14:37,200 bubbles in a milky way but even then it 368 00:14:40,220 --> 00:14:38,610 took this very careful job of 369 00:14:42,110 --> 00:14:40,230 subtracting the emission from the disk 370 00:14:43,670 --> 00:14:42,120 and a lot of processing to do that so 371 00:14:46,100 --> 00:14:43,680 that was a very challenging discovery 372 00:14:48,500 --> 00:14:46,110 even in our own Milky Way so when you go 373 00:14:50,389 --> 00:14:48,510 to another galaxy which is much further 374 00:14:52,819 --> 00:14:50,399 away so the emission is much fainter 375 00:14:54,560 --> 00:14:52,829 once by the time it's got to us it's so 376 00:14:56,750 --> 00:14:54,570 challenging that we haven't been able to 377 00:14:58,819 --> 00:14:56,760 see them but even is that true even for 378 00:15:00,920 --> 00:14:58,829 the more nearby galaxies I mean the last 379 00:15:03,139 --> 00:15:00,930 part of his question is or could this 380 00:15:05,030 --> 00:15:03,149 image or could imaging this in Andromeda 381 00:15:06,560 --> 00:15:05,040 be tried could you see that's maybe in a 382 00:15:09,620 --> 00:15:06,570 closed galaxy like the Andromeda galaxy 383 00:15:12,170 --> 00:15:09,630 you could try this in x-rays in 384 00:15:13,910 --> 00:15:12,180 Andromeda certainly in radio waves so in 385 00:15:17,389 --> 00:15:13,920 other wavelengths it's certainly true 386 00:15:19,519 --> 00:15:17,399 that we've seen extended halos and even 387 00:15:24,110 --> 00:15:19,529 bubble type structures in galaxies and 388 00:15:26,329 --> 00:15:24,120 galaxy clusters so particularly radio 389 00:15:28,180 --> 00:15:26,339 waves people have studied bubble 390 00:15:30,949 --> 00:15:28,190 structures in radio waves in other 391 00:15:32,960 --> 00:15:30,959 galaxies for some time but the gamma ray 392 00:15:34,850 --> 00:15:32,970 part of it and they and that's what led 393 00:15:37,880 --> 00:15:34,860 to this Fermi bubble name 394 00:15:41,600 --> 00:15:37,890 at the moment that's our own galaxy even 395 00:15:44,870 --> 00:15:41,610 Andromeda the closest big spiral galaxy 396 00:15:46,220 --> 00:15:44,880 to the Milky Way would if it had Fermi 397 00:15:48,230 --> 00:15:46,230 bubbles that were the same size as the 398 00:15:50,600 --> 00:15:48,240 Milky Way they would be too faint for us 399 00:15:52,160 --> 00:15:50,610 to see without current telescopes got it 400 00:15:54,560 --> 00:15:52,170 okay thanks ed that was a good question 401 00:15:56,270 --> 00:15:54,570 and so it would seem to me like you said 402 00:15:58,610 --> 00:15:56,280 there's two prevailing theories about 403 00:16:01,490 --> 00:15:58,620 what's causing these things and one of 404 00:16:03,260 --> 00:16:01,500 them was the black hole our supermassive 405 00:16:06,620 --> 00:16:03,270 black hole in the center of our galaxy I 406 00:16:07,910 --> 00:16:06,630 wonder wouldn't there be an NR and of 407 00:16:10,250 --> 00:16:07,920 course there are active and inactive 408 00:16:12,320 --> 00:16:10,260 periods of that black hole don't you 409 00:16:15,530 --> 00:16:12,330 think that would have a characteristic 410 00:16:19,090 --> 00:16:15,540 pattern to it if to these bubbles if it 411 00:16:23,660 --> 00:16:19,100 were sometimes being contributed to by a 412 00:16:25,880 --> 00:16:23,670 black hole Jets and other times not you 413 00:16:27,710 --> 00:16:25,890 understand what I'm asking yeah so 414 00:16:30,500 --> 00:16:27,720 wouldn't you expect to see some kind of 415 00:16:33,530 --> 00:16:30,510 I don't know rings or patterning to the 416 00:16:37,160 --> 00:16:33,540 bubbles yes I see what you're saying 417 00:16:38,570 --> 00:16:37,170 so we happen to have observed the 418 00:16:43,100 --> 00:16:38,580 bubbles as they are right now 419 00:16:45,470 --> 00:16:43,110 so our work with the Hubble telescope 420 00:16:47,120 --> 00:16:45,480 has actually given us an age of how long 421 00:16:49,370 --> 00:16:47,130 has it taken the gas to flow out from 422 00:16:51,110 --> 00:16:49,380 the center of the galaxy to where we 423 00:16:53,780 --> 00:16:51,120 observe it in this outflow where it's 424 00:16:55,580 --> 00:16:53,790 feeding the Fermi bubbles okay and that 425 00:16:59,030 --> 00:16:55,590 age is to about two or three million 426 00:17:00,560 --> 00:16:59,040 years so what not saying is that we two 427 00:17:02,510 --> 00:17:00,570 or three million years ago there was an 428 00:17:06,320 --> 00:17:02,520 event at the galactic center which blew 429 00:17:08,300 --> 00:17:06,330 out material and it is currently reached 430 00:17:10,160 --> 00:17:08,310 where we see it on the sky if someone 431 00:17:12,950 --> 00:17:10,170 was to come back in another two million 432 00:17:14,690 --> 00:17:12,960 years from now or you know whatever 433 00:17:16,640 --> 00:17:14,700 number of million years and observe it 434 00:17:18,740 --> 00:17:16,650 they would find the structure has got to 435 00:17:20,300 --> 00:17:18,750 a different stage so we're only looking 436 00:17:23,420 --> 00:17:20,310 at it at one point in time that's the 437 00:17:25,010 --> 00:17:23,430 difficulty and we've been able to chart 438 00:17:27,200 --> 00:17:25,020 how it's changing then we could really 439 00:17:30,200 --> 00:17:27,210 see how often is it expanding or is it 440 00:17:32,180 --> 00:17:30,210 going to reach maximum size okay we're 441 00:17:33,950 --> 00:17:32,190 just limited by the fact we can only see 442 00:17:35,900 --> 00:17:33,960 it right now at the current time you got 443 00:17:42,070 --> 00:17:35,910 it okay that's good so let's get to your 444 00:17:46,190 --> 00:17:44,570 bubbles are in a very interesting way 445 00:17:47,580 --> 00:17:46,200 they would turn Zout there was a quasar 446 00:17:50,380 --> 00:17:47,590 that happened 447 00:17:52,720 --> 00:17:50,390 to be in a certain location that was 448 00:17:54,490 --> 00:17:52,730 very fortuitous why don't you want you 449 00:17:59,200 --> 00:17:54,500 give us the background of the 450 00:18:00,760 --> 00:17:59,210 observations that you made sure so if we 451 00:18:01,600 --> 00:18:00,770 can pull up the slide to help show this 452 00:18:02,890 --> 00:18:01,610 that would be great 453 00:18:04,830 --> 00:18:02,900 that's right there's a schematic if you 454 00:18:07,060 --> 00:18:04,840 could do that Scot thank you what we've 455 00:18:11,260 --> 00:18:07,070 what we've been doing is thinking about 456 00:18:13,480 --> 00:18:11,270 how to use the Hubble telescope to study 457 00:18:15,370 --> 00:18:13,490 these Fermi bubbles and here you can see 458 00:18:16,630 --> 00:18:15,380 this is another side on view of what 459 00:18:18,910 --> 00:18:16,640 these things would look like from the 460 00:18:21,010 --> 00:18:18,920 outside of galaxy you know the Hubble 461 00:18:24,250 --> 00:18:21,020 telescope is over there in the disk on 462 00:18:27,970 --> 00:18:24,260 the right now we identified quasars that 463 00:18:31,090 --> 00:18:27,980 is very bright sources of radiation that 464 00:18:34,270 --> 00:18:31,100 happened to lie behind the bubbles so 465 00:18:36,660 --> 00:18:34,280 there's the sight line in yellow towards 466 00:18:39,070 --> 00:18:36,670 a bright quasar which in our case was 467 00:18:41,650 --> 00:18:39,080 just at the right place of the sky it 468 00:18:43,870 --> 00:18:41,660 had the right coordinates to lie close 469 00:18:47,110 --> 00:18:43,880 to the bottom of the northern fermi 470 00:18:48,760 --> 00:18:47,120 bubble one of the two bubbles and what 471 00:18:50,530 --> 00:18:48,770 we can do is we can take the light from 472 00:18:52,990 --> 00:18:50,540 this quasar in fact the ultraviolet 473 00:18:54,970 --> 00:18:53,000 light which Hubble is sensitive to 474 00:18:57,400 --> 00:18:54,980 because it's up in orbit above the 475 00:18:58,720 --> 00:18:57,410 Earth's atmosphere so it can it can make 476 00:19:00,190 --> 00:18:58,730 measurements all the way down into the 477 00:19:02,440 --> 00:19:00,200 ultraviolet which you can't do from the 478 00:19:04,720 --> 00:19:02,450 ground and by analyzing that ultraviolet 479 00:19:08,530 --> 00:19:04,730 light we can say something about the 480 00:19:10,600 --> 00:19:08,540 outflowing gas in the Fermi bubble and 481 00:19:12,700 --> 00:19:10,610 the reason is is that that outflowing 482 00:19:14,890 --> 00:19:12,710 gas leaves its signature in the 483 00:19:18,370 --> 00:19:14,900 ultraviolet light it leaves a signature 484 00:19:21,250 --> 00:19:18,380 in which frequencies of light which 485 00:19:24,549 --> 00:19:21,260 colors of light are absorbed and taken 486 00:19:26,500 --> 00:19:24,559 out of there of the spectrum so we do 487 00:19:30,270 --> 00:19:26,510 what we call a spectroscopic analysis 488 00:19:32,350 --> 00:19:30,280 and we measure lines of certain elements 489 00:19:33,760 --> 00:19:32,360 spectral lines which appear in the 490 00:19:36,549 --> 00:19:33,770 ultraviolet and that's a way of 491 00:19:39,220 --> 00:19:36,559 measuring the the properties of the gas 492 00:19:41,350 --> 00:19:39,230 that's in these bubbles and that was how 493 00:19:44,549 --> 00:19:41,360 we were able for the first time to 494 00:19:47,140 --> 00:19:44,559 measure what is the velocity of the gas 495 00:19:49,419 --> 00:19:47,150 coming out of the milky way's nucleus 496 00:19:50,890 --> 00:19:49,429 into the Fermi levels and we were also 497 00:19:53,370 --> 00:19:50,900 able to say something about what's its 498 00:19:56,409 --> 00:19:53,380 compositions and which elements are 499 00:19:57,820 --> 00:19:56,419 actually present in that gas because 500 00:19:59,860 --> 00:19:57,830 that also gives you a clue about where 501 00:20:01,030 --> 00:19:59,870 these things came from okay let's start 502 00:20:02,860 --> 00:20:01,040 with what they're made of for 503 00:20:03,970 --> 00:20:02,870 what did you discover what's what are 504 00:20:06,100 --> 00:20:03,980 these cat what are these clouds made of 505 00:20:10,720 --> 00:20:06,110 so the elements that we detected are 506 00:20:13,900 --> 00:20:10,730 silicon carbon and aluminum each of 507 00:20:15,430 --> 00:20:13,910 those elements has several of these 508 00:20:16,750 --> 00:20:15,440 spectral lines that fall in the 509 00:20:18,280 --> 00:20:16,760 ultraviolet that we can measure or we 510 00:20:21,060 --> 00:20:18,290 can see how strong how much of these 511 00:20:23,680 --> 00:20:21,070 elements are present in the in the gas 512 00:20:26,260 --> 00:20:23,690 sorry do you do you have the spectrum 513 00:20:32,860 --> 00:20:26,270 I was just going to say it looks like 514 00:20:37,090 --> 00:20:32,870 it's not okay on the image press release 515 00:20:39,340 --> 00:20:37,100 but we can use this one okay so this is 516 00:20:41,290 --> 00:20:39,350 this is the sort of data that we that we 517 00:20:45,010 --> 00:20:41,300 really work with when we get down to the 518 00:20:46,630 --> 00:20:45,020 details of analyzing the the Hubble data 519 00:20:48,570 --> 00:20:46,640 this is the spectrum which shows 520 00:20:51,280 --> 00:20:48,580 intensity or how much light there is 521 00:20:53,410 --> 00:20:51,290 against velocity along the line of sight 522 00:20:55,420 --> 00:20:53,420 and this is for a particular line this 523 00:20:56,860 --> 00:20:55,430 is twice ionized silicon and silicon 524 00:21:00,970 --> 00:20:56,870 atoms that have had two electrons 525 00:21:03,100 --> 00:21:00,980 removed from them now that gives you a 526 00:21:04,510 --> 00:21:03,110 feature at a very certain wavelength in 527 00:21:05,920 --> 00:21:04,520 the spectrum and we know exactly where 528 00:21:09,160 --> 00:21:05,930 that is in the spectrum so we know where 529 00:21:10,720 --> 00:21:09,170 to look what you see here is different 530 00:21:12,340 --> 00:21:10,730 components and those components are 531 00:21:15,060 --> 00:21:12,350 shaded in different colors this one 532 00:21:18,700 --> 00:21:15,070 shaded in blue at negative velocities 533 00:21:21,940 --> 00:21:18,710 two on the on the other side at positive 534 00:21:23,740 --> 00:21:21,950 velocities in yellow and in orange what 535 00:21:26,980 --> 00:21:23,750 this is telling you is it's basically 536 00:21:30,160 --> 00:21:26,990 using the Doppler effect the component 537 00:21:31,780 --> 00:21:30,170 that is shaded in blue that is moving 538 00:21:36,070 --> 00:21:31,790 towards us it's what we call blue 539 00:21:39,700 --> 00:21:36,080 shifted right it's gas that is we think 540 00:21:41,650 --> 00:21:39,710 on the near side of this outflowing cone 541 00:21:43,750 --> 00:21:41,660 of gas that comes out from the galactic 542 00:21:45,970 --> 00:21:43,760 center the yellow and the orange 543 00:21:47,680 --> 00:21:45,980 components are red shifted then light 544 00:21:49,990 --> 00:21:47,690 has been shifted towards the red and 545 00:21:51,850 --> 00:21:50,000 that's what you get from the far side of 546 00:21:54,310 --> 00:21:51,860 the outflow which is on the other side 547 00:21:56,050 --> 00:21:54,320 of the galactic center so just in this 548 00:21:57,490 --> 00:21:56,060 one sight line we can see these gas 549 00:21:58,810 --> 00:21:57,500 components some of which is coming 550 00:22:01,150 --> 00:21:58,820 towards you some of which is going away 551 00:22:03,820 --> 00:22:01,160 from you and that's exactly what you get 552 00:22:07,450 --> 00:22:03,830 from one of these nuclear outflows that 553 00:22:09,490 --> 00:22:07,460 comes out in a cone shaped pattern and 554 00:22:10,750 --> 00:22:09,500 so the silicon I'm going to get to the 555 00:22:13,030 --> 00:22:10,760 speeds and the velocities in just a 556 00:22:15,130 --> 00:22:13,040 minute but I want to I want to go what 557 00:22:17,150 --> 00:22:15,140 does the elements themselves 558 00:22:19,190 --> 00:22:17,160 telling you that does it give you any 559 00:22:20,780 --> 00:22:19,200 information about what their source 560 00:22:23,390 --> 00:22:20,790 might be what might be causing these 561 00:22:25,330 --> 00:22:23,400 well it does give you it does give you 562 00:22:27,770 --> 00:22:25,340 information but unfortunately it's not 563 00:22:30,140 --> 00:22:27,780 conclusive in telling you if it's the 564 00:22:32,300 --> 00:22:30,150 black hole or the star formation okay so 565 00:22:34,040 --> 00:22:32,310 look at the carbon and the aluminum we 566 00:22:36,080 --> 00:22:34,050 do know that those elements are all 567 00:22:38,030 --> 00:22:36,090 produced in stars in star formation they 568 00:22:39,710 --> 00:22:38,040 get they get forged in the cores of 569 00:22:42,200 --> 00:22:39,720 massive stars and they eventually do get 570 00:22:44,600 --> 00:22:42,210 released but what you don't know is how 571 00:22:47,180 --> 00:22:44,610 long ago that happened so it could have 572 00:22:51,110 --> 00:22:47,190 been that these elements are produced in 573 00:22:52,790 --> 00:22:51,120 stars they're released into the space 574 00:22:55,580 --> 00:22:52,800 between stars and then some of that gets 575 00:22:57,590 --> 00:22:55,590 accreted onto the the central black hole 576 00:23:00,050 --> 00:22:57,600 or it could have been that they just get 577 00:23:03,170 --> 00:23:00,060 loans directly out from from the 578 00:23:05,090 --> 00:23:03,180 supernovae in other words it doesn't 579 00:23:06,830 --> 00:23:05,100 really tell you for sure whether it's 580 00:23:08,840 --> 00:23:06,840 the star formation model or the black 581 00:23:10,910 --> 00:23:08,850 hole model but it does tell you that at 582 00:23:14,140 --> 00:23:10,920 some point this gas was processed 583 00:23:16,850 --> 00:23:14,150 through star formations clues to its 584 00:23:18,140 --> 00:23:16,860 origin so it's still there's still the 585 00:23:21,110 --> 00:23:18,150 jury's still out there's just not a 586 00:23:23,120 --> 00:23:21,120 there's not a conclusive fingerprint 587 00:23:25,670 --> 00:23:23,130 here in just the spectrum itself just 588 00:23:27,620 --> 00:23:25,680 the elements themselves so uh but I want 589 00:23:29,300 --> 00:23:27,630 to get to the velocity now and talk of 590 00:23:30,530 --> 00:23:29,310 so but before I do the Doppler effect 591 00:23:32,690 --> 00:23:30,540 that you're talking about let me just 592 00:23:34,910 --> 00:23:32,700 try and see if I can give a little bit a 593 00:23:39,590 --> 00:23:34,920 basic background on this if you take a 594 00:23:42,800 --> 00:23:39,600 spectrum of of an object at rest you 595 00:23:45,770 --> 00:23:42,810 will see certain lines dark and bright 596 00:23:48,980 --> 00:23:45,780 lines appear at it's very specific spots 597 00:23:51,170 --> 00:23:48,990 in the spectrum depending on what the 598 00:23:53,210 --> 00:23:51,180 element is and if that thing is moving 599 00:23:54,590 --> 00:23:53,220 what you will whatever it is you're 600 00:23:56,690 --> 00:23:54,600 measuring you will actually see all of 601 00:23:59,150 --> 00:23:56,700 those lines shifted one way or another 602 00:24:00,740 --> 00:23:59,160 and it will be shifted how much is 603 00:24:02,630 --> 00:24:00,750 shifted gives you an idea of how fast 604 00:24:04,730 --> 00:24:02,640 it's going and which direction it 605 00:24:07,010 --> 00:24:04,740 shifted tells you whether it's coming 606 00:24:10,100 --> 00:24:07,020 towards you or away from you so that is 607 00:24:12,740 --> 00:24:10,110 how the Doppler shift is used in spectra 608 00:24:15,500 --> 00:24:12,750 and you can see it in this in this graph 609 00:24:18,710 --> 00:24:15,510 alright so that the dotted line that 610 00:24:22,390 --> 00:24:18,720 goes horizontally is essentially the 611 00:24:26,230 --> 00:24:22,400 ambient intensity and the light comes 612 00:24:27,769 --> 00:24:26,240 light comes from another source and hits 613 00:24:30,349 --> 00:24:27,779 silicon atom 614 00:24:32,930 --> 00:24:30,359 and is absorbed and so that central line 615 00:24:36,019 --> 00:24:32,940 is most of the silicon but if that 616 00:24:39,049 --> 00:24:36,029 silicon atom is moving and in case many 617 00:24:43,609 --> 00:24:39,059 silicon atoms moving or sort of an above 618 00:24:46,310 --> 00:24:43,619 motion light has to when it's absorbed 619 00:24:48,440 --> 00:24:46,320 is shifted either if the material is 620 00:24:51,469 --> 00:24:48,450 moving towards us or away and our 621 00:24:54,379 --> 00:24:51,479 analogy is always the train whistle here 622 00:24:56,899 --> 00:24:54,389 I pitch a neutral tone and then the low 623 00:24:59,239 --> 00:24:56,909 pitch as a train goes past you if it's 624 00:25:04,389 --> 00:24:59,249 blowing its whistle the whole time so 625 00:25:06,709 --> 00:25:04,399 that's also how speed radar works so I 626 00:25:08,149 --> 00:25:06,719 actually once got out of a ticket 627 00:25:09,379 --> 00:25:08,159 because I explained the Doppler effect 628 00:25:11,869 --> 00:25:09,389 to a cop 629 00:25:13,430 --> 00:25:11,879 I don't know he gave me a warning 630 00:25:15,859 --> 00:25:13,440 because I had given him a physics lesson 631 00:25:18,739 --> 00:25:15,869 but anyway I wouldn't try them but 632 00:25:21,499 --> 00:25:18,749 anyway by physics 633 00:25:23,209 --> 00:25:21,509 yeah really so so that's how they tell 634 00:25:24,889 --> 00:25:23,219 that the material is moving because 635 00:25:28,399 --> 00:25:24,899 there's nothing else I'm sore being in 636 00:25:31,219 --> 00:25:28,409 that region except the silicon good so 637 00:25:32,599 --> 00:25:31,229 and so now now Andy why don't you tell 638 00:25:34,909 --> 00:25:32,609 us a little bit about these speeds then 639 00:25:36,739 --> 00:25:34,919 you've got them at more or less going 640 00:25:38,839 --> 00:25:36,749 out at about plus or minus 200 641 00:25:41,779 --> 00:25:38,849 kilometers per second right that's right 642 00:25:44,180 --> 00:25:41,789 so that these velocities are what we 643 00:25:45,799 --> 00:25:44,190 measure along the line of sight so in 644 00:25:47,209 --> 00:25:45,809 other words when you look towards this 645 00:25:50,810 --> 00:25:47,219 quasar which is close to the galactic 646 00:25:52,849 --> 00:25:50,820 center the blue stuff is coming towards 647 00:25:55,639 --> 00:25:52,859 you about minus 250 kilometers per 648 00:25:58,519 --> 00:25:55,649 second or so the orange component is 649 00:26:00,769 --> 00:25:58,529 plus 250 kilometers per second but what 650 00:26:03,169 --> 00:26:00,779 we have to do is we have to realize that 651 00:26:05,680 --> 00:26:03,179 we're just seeing a projection along our 652 00:26:08,149 --> 00:26:05,690 line of sight of the outflow because it 653 00:26:11,239 --> 00:26:08,159 our understanding is that most of the 654 00:26:13,849 --> 00:26:11,249 gas is moving directly out from the 655 00:26:16,099 --> 00:26:13,859 galactic center so up into the halo of 656 00:26:17,690 --> 00:26:16,109 the galaxy what you see is the 657 00:26:19,519 --> 00:26:17,700 projection of that onto our line of 658 00:26:21,349 --> 00:26:19,529 sight so we had to do a little bit of 659 00:26:24,320 --> 00:26:21,359 geometry to determine what is the 660 00:26:26,180 --> 00:26:24,330 outflow speed the actual the total 661 00:26:28,190 --> 00:26:26,190 velocity of the gas that moves away from 662 00:26:30,259 --> 00:26:28,200 the center of the galaxy because that's 663 00:26:32,359 --> 00:26:30,269 not the same as what we see along our 664 00:26:35,029 --> 00:26:32,369 line of sight I don't understand so you 665 00:26:37,129 --> 00:26:35,039 this is a measurement of one specific 666 00:26:39,169 --> 00:26:37,139 path of the better light that the quasar 667 00:26:40,400 --> 00:26:39,179 went through so you know about the gas 668 00:26:42,230 --> 00:26:40,410 right there 669 00:26:44,570 --> 00:26:42,240 you do and what what did you do now to 670 00:26:47,150 --> 00:26:44,580 figure out the rest I don't know so 671 00:26:48,860 --> 00:26:47,160 you're measuring along that line of 672 00:26:51,620 --> 00:26:48,870 sight towards this particular quasar 673 00:26:53,150 --> 00:26:51,630 right you have one data point right one 674 00:26:55,520 --> 00:26:53,160 of these components are coming towards 675 00:26:57,470 --> 00:26:55,530 you or away from you but in reality this 676 00:26:59,660 --> 00:26:57,480 gas is moving in three dimensions not 677 00:27:01,940 --> 00:26:59,670 just in one dimension towards us or away 678 00:27:04,640 --> 00:27:01,950 from us so we have to do some geometry 679 00:27:07,370 --> 00:27:04,650 to determine how far it is it actually 680 00:27:09,020 --> 00:27:07,380 moving directly up if you imagine you're 681 00:27:11,840 --> 00:27:09,030 looking at that side view of the galaxy 682 00:27:15,140 --> 00:27:11,850 again the real the direction that this 683 00:27:17,990 --> 00:27:15,150 outflow is going is out into the halo up 684 00:27:19,340 --> 00:27:18,000 above from the galactic center so you're 685 00:27:20,960 --> 00:27:19,350 just what you were seeing in the 686 00:27:24,230 --> 00:27:20,970 spectrum is the component of that that 687 00:27:25,940 --> 00:27:24,240 is that is along your line of sight so 688 00:27:27,740 --> 00:27:25,950 they said that's just an extra stage 689 00:27:30,020 --> 00:27:27,750 that goes into our calculations that 690 00:27:32,960 --> 00:27:30,030 goes from our line-of-sight velocity to 691 00:27:35,540 --> 00:27:32,970 what is the actual outflow velocity in 692 00:27:37,820 --> 00:27:35,550 three dimensions which is how fast it is 693 00:27:39,320 --> 00:27:37,830 it is the gas launched from the galactic 694 00:27:43,580 --> 00:27:39,330 center because that number is much 695 00:27:45,650 --> 00:27:43,590 faster it's more like wow that's really 696 00:27:48,230 --> 00:27:45,660 fast so this there's a related comment 697 00:27:49,760 --> 00:27:48,240 in question here from Adam synergy and I 698 00:27:51,500 --> 00:27:49,770 wanted to highlight this he's going so 699 00:27:53,360 --> 00:27:51,510 this observation is just the beginning 700 00:27:54,800 --> 00:27:53,370 right surely you will need to repeat 701 00:27:57,200 --> 00:27:54,810 this many times with different 702 00:27:58,430 --> 00:27:57,210 background quasars to fully map the 703 00:28:00,260 --> 00:27:58,440 Fermi bubbles and you're saying there's 704 00:28:02,150 --> 00:28:00,270 a technique here for getting that 705 00:28:04,040 --> 00:28:02,160 information yeah now that's a very good 706 00:28:06,830 --> 00:28:04,050 question we do need to do that we we 707 00:28:08,360 --> 00:28:06,840 began our program with this one sight 708 00:28:10,340 --> 00:28:08,370 line because it just happened to lie in 709 00:28:12,320 --> 00:28:10,350 such a great place this is the best 710 00:28:14,120 --> 00:28:12,330 quasar we have in terms of being close 711 00:28:16,220 --> 00:28:14,130 to the galactic center where the wind is 712 00:28:18,050 --> 00:28:16,230 going to be strongest because whatever 713 00:28:19,640 --> 00:28:18,060 is producing this it's something to do 714 00:28:21,140 --> 00:28:19,650 with a galactic center it's either stars 715 00:28:23,240 --> 00:28:21,150 near the galactic center or it's the 716 00:28:24,830 --> 00:28:23,250 black hole optic electric center so we 717 00:28:26,990 --> 00:28:24,840 were looking for targets as close as 718 00:28:29,150 --> 00:28:27,000 possible to that point and this was the 719 00:28:31,970 --> 00:28:29,160 best quasar but our full sample is more 720 00:28:33,920 --> 00:28:31,980 like 20 or so quasars some of which are 721 00:28:38,000 --> 00:28:33,930 inside the Fermi bubbles some of which 722 00:28:39,800 --> 00:28:38,010 are just outside and we have the ongoing 723 00:28:42,530 --> 00:28:39,810 task right now of analyzing all that 724 00:28:44,810 --> 00:28:42,540 that data and measuring the absorption 725 00:28:46,100 --> 00:28:44,820 lines that we see in the just the same 726 00:28:47,510 --> 00:28:46,110 techniques we've been talking about we 727 00:28:49,700 --> 00:28:47,520 need to do that for the full sample not 728 00:28:51,350 --> 00:28:49,710 just this one case good a good question 729 00:28:52,820 --> 00:28:51,360 Adam thank you and Craig Landon I'm 730 00:28:53,840 --> 00:28:52,830 gonna get to yours in just a minute but 731 00:28:57,680 --> 00:28:53,850 so 732 00:28:59,600 --> 00:28:57,690 the the the the measurements you've got 733 00:29:01,159 --> 00:28:59,610 tell you a little bit about how these 734 00:29:02,600 --> 00:29:01,169 things are moving fast by the way these 735 00:29:05,480 --> 00:29:02,610 things are really moving out there and 736 00:29:07,010 --> 00:29:05,490 you said something earlier about this 737 00:29:09,230 --> 00:29:07,020 happened what was a two and a half 738 00:29:11,750 --> 00:29:09,240 million years ago or whatever it was it 739 00:29:14,090 --> 00:29:11,760 caused and is the way you found that out 740 00:29:15,470 --> 00:29:14,100 by running the the clock backwards going 741 00:29:18,200 --> 00:29:15,480 backward and you know how fast they are 742 00:29:19,460 --> 00:29:18,210 right now so you just figured out to get 743 00:29:20,240 --> 00:29:19,470 where they are now I must have taken 744 00:29:21,500 --> 00:29:20,250 them this long 745 00:29:26,029 --> 00:29:21,510 that's exactly right that's the 746 00:29:29,090 --> 00:29:26,039 calculation we did we so we measured the 747 00:29:30,680 --> 00:29:29,100 outflow velocity and found about 900 or 748 00:29:32,570 --> 00:29:30,690 a thousand kilometers per second and 749 00:29:37,250 --> 00:29:32,580 that's about two million miles per hour 750 00:29:38,240 --> 00:29:37,260 and more million miles an hour two 751 00:29:39,860 --> 00:29:38,250 million miles an hour 752 00:29:42,500 --> 00:29:39,870 gushing out from the galactic center 753 00:29:44,930 --> 00:29:42,510 because we know how far from a galactic 754 00:29:47,000 --> 00:29:44,940 center is reached we know the distance 755 00:29:48,529 --> 00:29:47,010 right so we've got a distance we've got 756 00:29:51,500 --> 00:29:48,539 a velocity we could turn back the clock 757 00:29:53,120 --> 00:29:51,510 and figure out the time and when you do 758 00:29:55,640 --> 00:29:53,130 that calculation the answer is somewhere 759 00:29:58,580 --> 00:29:55,650 between two and a half to three or four 760 00:30:00,409 --> 00:29:58,590 million years so it tells you that 761 00:30:03,919 --> 00:30:00,419 that's how long it's taken for the gas 762 00:30:06,350 --> 00:30:03,929 to to be driven away from the galactic 763 00:30:07,520 --> 00:30:06,360 center to where we see it or to put it 764 00:30:08,720 --> 00:30:07,530 differently it just tells you that two 765 00:30:10,460 --> 00:30:08,730 or three million years ago there was a 766 00:30:13,010 --> 00:30:10,470 very energetic event there were some 767 00:30:16,210 --> 00:30:13,020 fireworks something happened that was 768 00:30:18,770 --> 00:30:16,220 capable of driving this stuff out 769 00:30:24,110 --> 00:30:18,780 producing what we now see and Scott's 770 00:30:25,700 --> 00:30:24,120 got a very France friendly looking it's 771 00:30:27,049 --> 00:30:25,710 the chromatic up here to sort of show 772 00:30:30,200 --> 00:30:27,059 what we've been talking about all this 773 00:30:32,330 --> 00:30:30,210 time you could see the the where the red 774 00:30:34,820 --> 00:30:32,340 and the blue areas of the spectrum are 775 00:30:38,930 --> 00:30:34,830 in the little diagram in the lower left 776 00:30:40,159 --> 00:30:38,940 and the so it gives a sense a little bit 777 00:30:41,409 --> 00:30:40,169 more of what we were just talking about 778 00:30:43,610 --> 00:30:41,419 but this is more of an artist 779 00:30:48,049 --> 00:30:43,620 representation of that where the other 780 00:30:54,200 --> 00:30:48,059 stuff was actual and the others was 781 00:30:55,669 --> 00:30:54,210 actual data so okay so let's see we let 782 00:30:58,490 --> 00:30:55,679 me get to Craig Landon here he's got a 783 00:31:01,159 --> 00:30:58,500 question here for us that is what might 784 00:31:03,470 --> 00:31:01,169 be the contribution of gravitational 785 00:31:07,010 --> 00:31:03,480 waves to what can be inferred from the 786 00:31:08,690 --> 00:31:07,020 views and different wavelengths so you 787 00:31:10,280 --> 00:31:08,700 can grab any waves affect these in any 788 00:31:12,260 --> 00:31:10,290 way from what you've seen in the 789 00:31:12,980 --> 00:31:12,270 different wavelengths or is it too early 790 00:31:15,860 --> 00:31:12,990 to tell 791 00:31:18,200 --> 00:31:15,870 I think I think it's too early to say 792 00:31:20,990 --> 00:31:18,210 what the contribution of gravitational 793 00:31:22,550 --> 00:31:21,000 waves would be if I mean if there was a 794 00:31:24,080 --> 00:31:22,560 place where that would be relevant it 795 00:31:26,390 --> 00:31:24,090 would probably be very close to the 796 00:31:28,760 --> 00:31:26,400 center of the black at the black hole 797 00:31:30,740 --> 00:31:28,770 itself where you have a several million 798 00:31:33,980 --> 00:31:30,750 solar mass object which is certainly 799 00:31:37,460 --> 00:31:33,990 going to be disturbing the space-time 800 00:31:38,630 --> 00:31:37,470 around it but we we don't we don't see 801 00:31:40,820 --> 00:31:38,640 what a connection would be right now 802 00:31:44,320 --> 00:31:40,830 between these these observations of 803 00:31:47,510 --> 00:31:44,330 gravitational waves cool thanks Craig so 804 00:31:49,790 --> 00:31:47,520 how do we know how hot these things are 805 00:31:53,480 --> 00:31:49,800 we know how the temperature the gas well 806 00:31:56,590 --> 00:31:53,490 the gas that we're seeing in the Hubble 807 00:31:58,910 --> 00:31:56,600 data it's actually not that heart by 808 00:32:03,370 --> 00:31:58,920 astronomers standards it's probably 809 00:32:09,650 --> 00:32:08,240 17,000 Fahrenheit or so every day 810 00:32:12,050 --> 00:32:09,660 standards but in terms of like 811 00:32:13,370 --> 00:32:12,060 interstellar space that's not so hot 812 00:32:14,930 --> 00:32:13,380 there's a plenty of stuff which is at a 813 00:32:17,630 --> 00:32:14,940 million degrees or ten million degrees 814 00:32:18,740 --> 00:32:17,640 or hotter right and it's also not very 815 00:32:20,030 --> 00:32:18,750 dense right I was going to get to 816 00:32:23,720 --> 00:32:20,040 density too while we're talking about 817 00:32:26,390 --> 00:32:23,730 temperature are these very dense no not 818 00:32:27,710 --> 00:32:26,400 really I mean it the typical densities 819 00:32:29,720 --> 00:32:27,720 you have in these things are something 820 00:32:33,140 --> 00:32:29,730 like one atom per cubic centimeter 821 00:32:35,330 --> 00:32:33,150 okay char extraordinaire allele oh by 822 00:32:37,370 --> 00:32:35,340 our standards on earth but that's the 823 00:32:41,480 --> 00:32:37,380 sort of number you come across in 824 00:32:42,890 --> 00:32:41,490 interstellar space but the interesting 825 00:32:45,370 --> 00:32:42,900 thing about the temperature is if I can 826 00:32:48,680 --> 00:32:45,380 just come back to this point is sure 827 00:32:52,400 --> 00:32:48,690 people have been studying winds coming 828 00:32:53,900 --> 00:32:52,410 out of other galaxies and they haven't 829 00:32:55,370 --> 00:32:53,910 been able to see the bubbles because of 830 00:32:57,260 --> 00:32:55,380 what we talked about and gamma rays are 831 00:33:00,080 --> 00:32:57,270 too faint but they have been able to see 832 00:33:02,870 --> 00:33:00,090 winds and and when they studied winds 833 00:33:05,690 --> 00:33:02,880 and it's widely accepted that most of 834 00:33:07,910 --> 00:33:05,700 the wind and energy that comes out from 835 00:33:10,610 --> 00:33:07,920 the center of galaxies is very hot where 836 00:33:12,290 --> 00:33:10,620 it's it's extremely hard to detect so 837 00:33:14,720 --> 00:33:12,300 it's possible that what we're seeing in 838 00:33:17,000 --> 00:33:14,730 this cooler gas and with the Hubble data 839 00:33:18,950 --> 00:33:17,010 are just small clouds that are being 840 00:33:21,530 --> 00:33:18,960 taken along for the ride in the outflow 841 00:33:23,210 --> 00:33:21,540 we're not really seeing 842 00:33:25,160 --> 00:33:23,220 the bulk of the mass the bulk of the 843 00:33:27,320 --> 00:33:25,170 energy in the wind we're just seeing 844 00:33:29,300 --> 00:33:27,330 small pockets of material that are 845 00:33:31,610 --> 00:33:29,310 relatively dense and are being taken 846 00:33:33,290 --> 00:33:31,620 along for the ride now this is really 847 00:33:36,130 --> 00:33:33,300 interesting I hadn't heard this so in 848 00:33:38,150 --> 00:33:36,140 galactic winds you're the entire 849 00:33:39,710 --> 00:33:38,160 describe what those would be like I 850 00:33:42,230 --> 00:33:39,720 don't I I'm having trouble visually is 851 00:33:46,430 --> 00:33:42,240 it the entire galaxy blowing out well 852 00:33:48,650 --> 00:33:46,440 yes it could be galactic wide winds I'm 853 00:33:52,100 --> 00:33:48,660 focusing here more on the Galactic 854 00:33:54,470 --> 00:33:52,110 nuclear winds okay but if you if you if 855 00:33:55,640 --> 00:33:54,480 you look at the the supernova model 856 00:33:58,490 --> 00:33:55,650 where it's the supernovae that are 857 00:34:00,170 --> 00:33:58,500 powering the outflow those explosions 858 00:34:02,230 --> 00:34:00,180 heat the gas to extremely high 859 00:34:06,140 --> 00:34:02,240 temperatures well over a million degrees 860 00:34:09,890 --> 00:34:06,150 that is the type of gas that can expand 861 00:34:11,900 --> 00:34:09,900 and blow a wind out into the halo so you 862 00:34:14,570 --> 00:34:11,910 could think of that as the real hot wind 863 00:34:16,490 --> 00:34:14,580 and a little cool cool clumps that we 864 00:34:18,500 --> 00:34:16,500 see they're just catching a ride they're 865 00:34:20,900 --> 00:34:18,510 just surfing the waves up into the halo 866 00:34:23,540 --> 00:34:20,910 but this is the interesting thing so 867 00:34:25,310 --> 00:34:23,550 we're not really seeing all of the gas 868 00:34:27,230 --> 00:34:25,320 by any means we're just seeing the small 869 00:34:29,690 --> 00:34:27,240 clumps that are at the right temperature 870 00:34:31,130 --> 00:34:29,700 that Hubble can see them because for all 871 00:34:32,390 --> 00:34:31,140 the wonderful things that Hubble can do 872 00:34:34,940 --> 00:34:32,400 in the ultraviolet it can't actually 873 00:34:37,940 --> 00:34:34,950 measure the really hot million degree 874 00:34:39,470 --> 00:34:37,950 phase it is where theorists think most 875 00:34:40,159 --> 00:34:39,480 of them when most of the energy is being 876 00:34:42,230 --> 00:34:40,169 carried 877 00:34:43,820 --> 00:34:42,240 okay so what's confusing about that to 878 00:34:45,650 --> 00:34:43,830 me is that we can see these winds in 879 00:34:50,030 --> 00:34:45,660 other galaxies but we can't see it in 880 00:34:52,909 --> 00:34:50,040 our own we can see winds and in x-rays 881 00:34:56,780 --> 00:34:52,919 the one thing we can we can in our 882 00:34:59,930 --> 00:34:56,790 galaxy or in distant galaxies well both 883 00:35:01,970 --> 00:34:59,940 okay the difficulty in our own galaxy is 884 00:35:03,220 --> 00:35:01,980 that you've got this problem of being 885 00:35:05,660 --> 00:35:03,230 able to see the forest for the trees 886 00:35:06,230 --> 00:35:05,670 because we're right here in the disk of 887 00:35:08,300 --> 00:35:06,240 the galaxy 888 00:35:10,460 --> 00:35:08,310 okay so we're rotating there's a lot of 889 00:35:13,460 --> 00:35:10,470 foreground material right between us and 890 00:35:15,020 --> 00:35:13,470 the galactic center so ironically it's 891 00:35:16,970 --> 00:35:15,030 actually harder sometimes to figure out 892 00:35:19,100 --> 00:35:16,980 what's going on at the centre of the 893 00:35:20,930 --> 00:35:19,110 Milky Way then you look at another 894 00:35:23,480 --> 00:35:20,940 galaxy it's further away but you've got 895 00:35:26,420 --> 00:35:23,490 a clean shot at it so you can you don't 896 00:35:28,280 --> 00:35:26,430 have all the foreground issues to deal 897 00:35:29,810 --> 00:35:28,290 with okay so it's the same probably have 898 00:35:32,300 --> 00:35:29,820 a seeing the bubbles at all you've got 899 00:35:34,310 --> 00:35:32,310 so much our galaxy is so bright that 900 00:35:37,400 --> 00:35:34,320 it's in the way of seeing these winds 901 00:35:40,610 --> 00:35:37,410 in any meaningful way so yeah okay 902 00:35:42,970 --> 00:35:40,620 laughing right okay well uh so that we 903 00:35:45,110 --> 00:35:42,980 have another comment here from oh and we 904 00:35:47,090 --> 00:35:45,120 Philippe Philippe OH 905 00:35:49,670 --> 00:35:47,100 Conte is it possible that the event 906 00:35:51,290 --> 00:35:49,680 horizon is something like a sphere and 907 00:35:53,450 --> 00:35:51,300 so the bubbles are just formed by 908 00:35:55,370 --> 00:35:53,460 materials that are going towards the 909 00:35:57,830 --> 00:35:55,380 horizon from both sides 910 00:36:00,800 --> 00:35:57,840 I guess that's more of a geometry of the 911 00:36:03,050 --> 00:36:00,810 of the black hole contribution question 912 00:36:03,470 --> 00:36:03,060 right that's a that's an interesting 913 00:36:05,750 --> 00:36:03,480 thought 914 00:36:09,620 --> 00:36:05,760 so if if the Fermi bubbles are being 915 00:36:11,540 --> 00:36:09,630 powered by the black hole then of course 916 00:36:13,340 --> 00:36:11,550 nothing can escape from the event 917 00:36:14,990 --> 00:36:13,350 horizon of that black hole but you can 918 00:36:17,330 --> 00:36:15,000 get material which escapes from the 919 00:36:18,920 --> 00:36:17,340 region just around the event horizon so 920 00:36:21,440 --> 00:36:18,930 if we have this accretion disk which is 921 00:36:23,630 --> 00:36:21,450 where the gas gets really hot and is 922 00:36:25,760 --> 00:36:23,640 falling towards and swirling onto the 923 00:36:30,680 --> 00:36:25,770 black hole that's the region where you 924 00:36:32,840 --> 00:36:30,690 can get outflows that drive into the 925 00:36:33,890 --> 00:36:32,850 bubbles maybe even Jets as well we 926 00:36:38,420 --> 00:36:33,900 haven't talked about Jets 927 00:36:40,400 --> 00:36:38,430 but there is one theoretical model which 928 00:36:42,470 --> 00:36:40,410 says that you can drive these Jets out 929 00:36:45,610 --> 00:36:42,480 from the supermassive black hole and 930 00:36:48,080 --> 00:36:45,620 that is what is contributing towards the 931 00:36:49,190 --> 00:36:48,090 Fermi bubbles oh okay that's right so 932 00:36:53,060 --> 00:36:49,200 that would be these high energy Jets 933 00:36:54,890 --> 00:36:53,070 that are in very active galactic nuclei 934 00:36:57,170 --> 00:36:54,900 or black holes that's right and you see 935 00:37:00,680 --> 00:36:57,180 these Jets around other active galactic 936 00:37:02,750 --> 00:37:00,690 nuclei other galaxies exactly but they 937 00:37:05,300 --> 00:37:02,760 would be formed somewhere fairly close 938 00:37:07,820 --> 00:37:05,310 into the center of the black hole but 939 00:37:10,340 --> 00:37:07,830 still outside the event horizon okay 940 00:37:14,480 --> 00:37:10,350 good that's a good question okay so all 941 00:37:17,840 --> 00:37:14,490 right so so I may I may have missed this 942 00:37:22,070 --> 00:37:17,850 but but so there's this bubble but so 943 00:37:25,460 --> 00:37:22,080 it's it's the waste if you will is tight 944 00:37:28,430 --> 00:37:25,470 at least the way you have detected it is 945 00:37:30,760 --> 00:37:28,440 tight near the plane is there still as a 946 00:37:35,000 --> 00:37:30,770 mission within the plane of the galaxy 947 00:37:35,870 --> 00:37:35,010 caused by the same sources right that's 948 00:37:39,470 --> 00:37:35,880 right yes 949 00:37:42,800 --> 00:37:39,480 it's not necessarily it could be but 950 00:37:44,570 --> 00:37:42,810 nuts is necessarily white bipolar like 951 00:37:45,800 --> 00:37:44,580 that is that right yes that's right so 952 00:37:47,640 --> 00:37:45,810 that waste is telling you something 953 00:37:50,190 --> 00:37:47,650 important because 954 00:37:51,990 --> 00:37:50,200 what we think is happening is that the 955 00:37:54,090 --> 00:37:52,000 the firming bubble however it gets 956 00:37:57,300 --> 00:37:54,100 created it has to expand into something 957 00:38:01,140 --> 00:37:57,310 and the denser material in it then it 958 00:38:03,630 --> 00:38:01,150 expands into the harder it is to to get 959 00:38:06,390 --> 00:38:03,640 bigger whereas the less dense the easier 960 00:38:08,280 --> 00:38:06,400 it is to expand so naturally the bubbles 961 00:38:10,050 --> 00:38:08,290 just inflate and get bigger away from 962 00:38:13,200 --> 00:38:10,060 the galactic center in the vertical 963 00:38:14,520 --> 00:38:13,210 direction but in the waste direction 964 00:38:15,900 --> 00:38:14,530 sort of towards the sides they're 965 00:38:17,370 --> 00:38:15,910 probably encountering a lot more 966 00:38:19,410 --> 00:38:17,380 resistance because there's a lot more 967 00:38:21,990 --> 00:38:19,420 gas there there's a lot more interesting 968 00:38:23,640 --> 00:38:22,000 material and that's what's confining the 969 00:38:26,460 --> 00:38:23,650 bubbles and we think that that's where 970 00:38:28,110 --> 00:38:26,470 the waste structure the shape of these 971 00:38:31,800 --> 00:38:28,120 things comes from it's sort of set by 972 00:38:34,020 --> 00:38:31,810 what is restricting the stuff that's in 973 00:38:38,190 --> 00:38:34,030 the way right and we can't detect that 974 00:38:40,050 --> 00:38:38,200 way that way but in the plane we can't 975 00:38:42,390 --> 00:38:40,060 do this observation because there's all 976 00:38:43,680 --> 00:38:42,400 this other yeah besides we go through a 977 00:38:48,180 --> 00:38:43,690 lot of trouble to subtract all that out 978 00:38:50,070 --> 00:38:48,190 anyhow so it would be a tiny little yeah 979 00:38:53,550 --> 00:38:50,080 if we could see it at all okay so 980 00:38:56,280 --> 00:38:53,560 red-hot bagel is asking this might be a 981 00:38:58,260 --> 00:38:56,290 dumb question no such thing on our 982 00:38:59,610 --> 00:38:58,270 hangouts thank you for asking it's a 983 00:39:02,070 --> 00:38:59,620 really good question yes it's actually 984 00:39:04,020 --> 00:39:02,080 not a dumb question but how exactly do 985 00:39:06,620 --> 00:39:04,030 you measure the temperatures of these 986 00:39:11,760 --> 00:39:06,630 gases okay 987 00:39:15,410 --> 00:39:11,770 not a bad question at all we have access 988 00:39:18,210 --> 00:39:15,420 in the Cobbold ultraviolet data to 989 00:39:19,980 --> 00:39:18,220 different different lines I showed a 990 00:39:23,970 --> 00:39:19,990 line earlier on when we had a graphic up 991 00:39:26,220 --> 00:39:23,980 of twice ionized silicon so a silicon 992 00:39:28,470 --> 00:39:26,230 atom that's being ionized as I had two 993 00:39:30,660 --> 00:39:28,480 electrons taken out of it now the level 994 00:39:32,190 --> 00:39:30,670 of ionization so how many electrons has 995 00:39:34,410 --> 00:39:32,200 been removed tells you something about 996 00:39:37,290 --> 00:39:34,420 the temperature because the hotter the 997 00:39:39,120 --> 00:39:37,300 gas the more electrons will be removed 998 00:39:41,840 --> 00:39:39,130 from all the atoms whereas difficult is 999 00:39:46,200 --> 00:39:41,850 very cool the gas can be atomic or even 1000 00:39:47,280 --> 00:39:46,210 molecular so twice ionized silicon the 1001 00:39:49,550 --> 00:39:47,290 one that is shown in that particular 1002 00:39:51,710 --> 00:39:49,560 graph just happens to live in 1003 00:39:55,440 --> 00:39:51,720 interstellar gas at temperatures of 1004 00:39:57,510 --> 00:39:55,450 approximately 10,000 Kelvin you have to 1005 00:39:58,200 --> 00:39:57,520 describe for us twice ionized what do 1006 00:40:01,050 --> 00:39:58,210 you mean by that 1007 00:40:03,480 --> 00:40:01,060 so that means it's minus twice 1008 00:40:04,740 --> 00:40:03,490 I mean come on Tony I mean two electrons 1009 00:40:06,870 --> 00:40:04,750 have been taken out of it so if you 1010 00:40:07,260 --> 00:40:06,880 start with a neutral silicon atom thank 1011 00:40:12,960 --> 00:40:07,270 you 1012 00:40:14,790 --> 00:40:12,970 with what we call high silicon atoms and 1013 00:40:17,400 --> 00:40:14,800 that leaves its imprint at a certain 1014 00:40:18,540 --> 00:40:17,410 wavelength good I just wanted to get 1015 00:40:19,890 --> 00:40:18,550 that clear because a lot of it's not 1016 00:40:21,000 --> 00:40:19,900 clear what you know of the word ionized 1017 00:40:22,980 --> 00:40:21,010 is a big one so I wanna make sure we 1018 00:40:25,110 --> 00:40:22,990 explained out that it's not a very very 1019 00:40:28,160 --> 00:40:25,120 big long thermometer that we shove out 1020 00:40:30,660 --> 00:40:28,170 there we have ways of using the light to 1021 00:40:33,060 --> 00:40:30,670 to actually get the information the 1022 00:40:35,340 --> 00:40:33,070 spectra it's actually what's going on in 1023 00:40:37,260 --> 00:40:35,350 those in those gases and in those ions 1024 00:40:38,670 --> 00:40:37,270 to that let's go that's right and and 1025 00:40:39,930 --> 00:40:38,680 these ions each live at different 1026 00:40:42,390 --> 00:40:39,940 temperatures so that's the short answer 1027 00:40:44,400 --> 00:40:42,400 is that this one lives and approximately 1028 00:40:48,060 --> 00:40:44,410 10,000 Kelvin but it's certainly not a 1029 00:40:49,980 --> 00:40:48,070 very precise broke it could be eight 1030 00:40:50,640 --> 00:40:49,990 thousand ten thousand somewhere in that 1031 00:40:53,310 --> 00:40:50,650 ballpark 1032 00:40:55,140 --> 00:40:53,320 thank you red-hot bagel that was good 1033 00:40:57,650 --> 00:40:55,150 question very good question 1034 00:41:01,440 --> 00:40:57,660 so we touched on this briefly earlier 1035 00:41:03,210 --> 00:41:01,450 and I want to follow up with your 1036 00:41:04,980 --> 00:41:03,220 looking at other quasars I want to talk 1037 00:41:08,370 --> 00:41:04,990 about what's next what's the future here 1038 00:41:10,320 --> 00:41:08,380 what do you have up coming up for us in 1039 00:41:13,170 --> 00:41:10,330 terms of learning more about these Fermi 1040 00:41:15,600 --> 00:41:13,180 bubbles do you have anything planned so 1041 00:41:17,400 --> 00:41:15,610 we do we have the other quasars as I 1042 00:41:19,260 --> 00:41:17,410 mentioned there's about 20 of them that 1043 00:41:21,180 --> 00:41:19,270 we have we've we've got the data it's 1044 00:41:23,880 --> 00:41:21,190 just a question of measure analyzing all 1045 00:41:28,290 --> 00:41:23,890 these lines okay and and modeling the 1046 00:41:30,030 --> 00:41:28,300 outflow we also have some stars so it 1047 00:41:33,390 --> 00:41:30,040 turns out that the Milky Way is 1048 00:41:34,770 --> 00:41:33,400 cooperating and it gives us some similar 1049 00:41:37,140 --> 00:41:34,780 stars which are some of them actually 1050 00:41:38,430 --> 00:41:37,150 are in the Fermi bubbles and this is 1051 00:41:40,800 --> 00:41:38,440 really interesting because you think of 1052 00:41:43,560 --> 00:41:40,810 these Fermi bubbles is very energetic 1053 00:41:45,420 --> 00:41:43,570 places but there are these single stars 1054 00:41:47,910 --> 00:41:45,430 that happen to live in the halo of the 1055 00:41:49,470 --> 00:41:47,920 galaxy not in a disk but up there and we 1056 00:41:51,660 --> 00:41:49,480 know how far away they are these are 1057 00:41:53,250 --> 00:41:51,670 just errant stars that happen to be up 1058 00:41:54,480 --> 00:41:53,260 above the plane of the galaxy yep 1059 00:41:56,070 --> 00:41:54,490 they're just wayward and they've 1060 00:41:59,250 --> 00:41:56,080 wandered up there however that their 1061 00:42:01,050 --> 00:41:59,260 history did that to them but we can use 1062 00:42:03,120 --> 00:42:01,060 them and do the same experiment but now 1063 00:42:04,350 --> 00:42:03,130 the difference with these stars is that 1064 00:42:06,120 --> 00:42:04,360 because they're in the Fermi bubble 1065 00:42:07,530 --> 00:42:06,130 you're only seeing half of the outflow 1066 00:42:09,870 --> 00:42:07,540 you're only seeing a part of it which is 1067 00:42:11,310 --> 00:42:09,880 on the near side right whereas when we 1068 00:42:12,540 --> 00:42:11,320 do the quasar experiment that we've 1069 00:42:14,820 --> 00:42:12,550 already done you can see all the way 1070 00:42:16,110 --> 00:42:14,830 through the full path of the outflows 1071 00:42:20,010 --> 00:42:16,120 you can see the front side of it and you 1072 00:42:21,300 --> 00:42:20,020 can see the back side of it but still 1073 00:42:23,190 --> 00:42:21,310 that's better than nothing right that's 1074 00:42:27,630 --> 00:42:23,200 more information than we didn't have 1075 00:42:29,430 --> 00:42:27,640 that we have and there are one or two 1076 00:42:31,140 --> 00:42:29,440 cases where we have a full Brown star 1077 00:42:33,990 --> 00:42:31,150 which is it would believers in the Fermi 1078 00:42:35,850 --> 00:42:34,000 bubbles and a background quasar which is 1079 00:42:40,230 --> 00:42:35,860 very close to it on the sky so we can 1080 00:42:42,300 --> 00:42:40,240 compare the absorption spectrum and so 1081 00:42:44,700 --> 00:42:42,310 we can say something about well if we 1082 00:42:46,110 --> 00:42:44,710 see this feature in one side line and we 1083 00:42:49,020 --> 00:42:46,120 don't see it in the other one that gives 1084 00:42:52,710 --> 00:42:49,030 us some information about where it is in 1085 00:42:53,970 --> 00:42:52,720 turn so when you get not not that I want 1086 00:42:55,770 --> 00:42:53,980 to push you or anything but were you 1087 00:42:58,560 --> 00:42:55,780 gonna get all this done and come back 1088 00:43:01,830 --> 00:42:58,570 and tell us how it what you found out is 1089 00:43:04,110 --> 00:43:01,840 there a timeline I am confident that we 1090 00:43:06,570 --> 00:43:04,120 can make some good progress on that 1091 00:43:08,250 --> 00:43:06,580 within this year and I've got a great 1092 00:43:11,000 --> 00:43:08,260 team of people working with me on this 1093 00:43:13,770 --> 00:43:11,010 on this project people focusing on 1094 00:43:16,860 --> 00:43:13,780 modeling we've also got some some radio 1095 00:43:19,500 --> 00:43:16,870 data which which gives us a new a new 1096 00:43:21,000 --> 00:43:19,510 set of observations on how much neutral 1097 00:43:24,450 --> 00:43:21,010 gas there is that goes along with this 1098 00:43:26,520 --> 00:43:24,460 ionized stuff radio data from Alma this 1099 00:43:28,710 --> 00:43:26,530 is actually from the Green Bank 1100 00:43:31,380 --> 00:43:28,720 telescope which is in West Virginia okay 1101 00:43:34,020 --> 00:43:31,390 the old that's all school it is it's 1102 00:43:37,170 --> 00:43:34,030 cool but it's a fantastic facility it's 1103 00:43:41,040 --> 00:43:37,180 it's it's been around a long time well 1104 00:43:44,490 --> 00:43:41,050 this is a huge single dish telescope and 1105 00:43:46,530 --> 00:43:44,500 it provides very very deep observations 1106 00:43:48,660 --> 00:43:46,540 so for what we needed to do it's as good 1107 00:43:50,550 --> 00:43:48,670 as we could get when my friends went to 1108 00:43:53,490 --> 00:43:50,560 UVA and she she was working out there 1109 00:43:55,890 --> 00:43:53,500 and say no cellphones own don't bring 1110 00:43:57,930 --> 00:43:55,900 anything like that right that's a big 1111 00:43:59,970 --> 00:43:57,940 thing to think about because when when 1112 00:44:02,160 --> 00:43:59,980 we're talking about these wavelengths of 1113 00:44:04,170 --> 00:44:02,170 light that's what's going on with our 1114 00:44:06,090 --> 00:44:04,180 everyday gadgets is that that is light 1115 00:44:08,190 --> 00:44:06,100 and it's going to be interfering so this 1116 00:44:10,440 --> 00:44:08,200 place in Virginia you have it's 1117 00:44:13,380 --> 00:44:10,450 completely when you're talking about 1118 00:44:15,150 --> 00:44:13,390 light preservation is first dark skies 1119 00:44:17,100 --> 00:44:15,160 well we have to do the same thing with 1120 00:44:19,290 --> 00:44:17,110 these types of telescopes to make sure 1121 00:44:21,600 --> 00:44:19,300 there's no interference from these 1122 00:44:23,280 --> 00:44:21,610 longer wavelengths of light as well it's 1123 00:44:24,990 --> 00:44:23,290 the radio equivalent of shining a 1124 00:44:30,000 --> 00:44:25,000 flashlight down the tube 1125 00:44:31,589 --> 00:44:30,010 right okay so I Scott I do you have I 1126 00:44:33,870 --> 00:44:31,599 missed any any is there any Twitter 1127 00:44:35,820 --> 00:44:33,880 things there's a budget there's a bunch 1128 00:44:39,330 --> 00:44:35,830 of tweets a lot of retweets going on 1129 00:44:41,160 --> 00:44:39,340 there is escrow gingersnap also notice a 1130 00:44:44,130 --> 00:44:41,170 me lens like I think my head might 1131 00:44:46,440 --> 00:44:44,140 explode right now from awesome space 1132 00:44:49,710 --> 00:44:46,450 news today on Rosetta and the Hubble 1133 00:44:55,109 --> 00:44:49,720 hangout and Vesta so we are adding to 1134 00:44:57,780 --> 00:44:55,119 her Minds lotion of all great and and 1135 00:44:59,700 --> 00:44:57,790 Francis ready also shared out the the 1136 00:45:01,800 --> 00:44:59,710 NASA video release which I have put into 1137 00:45:04,410 --> 00:45:01,810 the Google+ event page so I have link to 1138 00:45:05,940 --> 00:45:04,420 that and it's really good it's a really 1139 00:45:09,690 --> 00:45:05,950 good animation showing the Fermi 1140 00:45:11,849 --> 00:45:09,700 spacecraft and also the the animation 1141 00:45:14,970 --> 00:45:11,859 going on - as far as explaining what's 1142 00:45:18,330 --> 00:45:14,980 going on with the with these Fermi 1143 00:45:21,960 --> 00:45:18,340 levels excellent yeah I have a question 1144 00:45:24,450 --> 00:45:21,970 so in principle if you were given Hubble 1145 00:45:26,640 --> 00:45:24,460 Space Telescope you could do a whole 1146 00:45:28,280 --> 00:45:26,650 bunch of sightlines then all over the 1147 00:45:30,329 --> 00:45:28,290 place and then you'd want to repeat that 1148 00:45:32,070 --> 00:45:30,339 periodically just to see what the 1149 00:45:34,079 --> 00:45:32,080 changes are right so you can map the 1150 00:45:36,960 --> 00:45:34,089 whole thing and then see how it changes 1151 00:45:39,870 --> 00:45:36,970 is that right don't get that in 1152 00:45:43,410 --> 00:45:39,880 principle the problem is actually the 1153 00:45:45,150 --> 00:45:43,420 timescales you would need so if if I all 1154 00:45:47,280 --> 00:45:45,160 my colleagues could lift her like two 1155 00:45:48,839 --> 00:45:47,290 million years then yes this at a time we 1156 00:45:51,599 --> 00:45:48,849 think we would need to see these things 1157 00:45:56,130 --> 00:45:51,609 actually change on this but you could do 1158 00:45:59,910 --> 00:45:56,140 different sight lines you could you 1159 00:46:02,370 --> 00:45:59,920 would look for other quasars that happen 1160 00:46:03,990 --> 00:46:02,380 to lie close to the galactic center and 1161 00:46:06,329 --> 00:46:04,000 do the same thing we got really lucky 1162 00:46:09,480 --> 00:46:06,339 with this one quasar because there's a 1163 00:46:12,030 --> 00:46:09,490 lot of dust what we call dust is like 1164 00:46:16,020 --> 00:46:12,040 interstellar particles they block the 1165 00:46:16,980 --> 00:46:16,030 light from background quasars especially 1166 00:46:19,260 --> 00:46:16,990 when you get close to the galactic 1167 00:46:21,810 --> 00:46:19,270 center it just happens there's like a 1168 00:46:24,030 --> 00:46:21,820 little window through through the the 1169 00:46:26,820 --> 00:46:24,040 low halo of the galaxy and this quasar 1170 00:46:28,620 --> 00:46:26,830 is in that window but other places 1171 00:46:30,089 --> 00:46:28,630 nearby have so much dust that the light 1172 00:46:32,400 --> 00:46:30,099 doesn't get through which means you 1173 00:46:35,160 --> 00:46:32,410 can't find the quasars you need to do 1174 00:46:37,230 --> 00:46:35,170 this type of experiment so it's hard but 1175 00:46:38,940 --> 00:46:37,240 we had to really push down and find very 1176 00:46:40,470 --> 00:46:38,950 faint sources to do this 1177 00:46:41,960 --> 00:46:40,480 take a lot of time a lot of observing 1178 00:46:44,430 --> 00:46:41,970 time on the telescope to get this done 1179 00:46:47,250 --> 00:46:44,440 pesky dust we gotta get a vacuum cleaner 1180 00:46:49,770 --> 00:46:47,260 out there and cleared out of the way all 1181 00:46:51,270 --> 00:46:49,780 right well so dr. Andy Fox I want to 1182 00:46:53,339 --> 00:46:51,280 thank you very much for joining us on 1183 00:46:55,079 --> 00:46:53,349 our hangout is you are you will you come 1184 00:46:58,410 --> 00:46:55,089 back later once you've got more more 1185 00:47:00,060 --> 00:46:58,420 data sure yeah awesome good look for 1186 00:47:03,210 --> 00:47:00,070 anybody I want to want to follow up on 1187 00:47:04,560 --> 00:47:03,220 this and look here's a final slide I did 1188 00:47:06,000 --> 00:47:04,570 it also put the link out there and bout 1189 00:47:08,010 --> 00:47:06,010 to put up on Twitter here in a bit but 1190 00:47:10,079 --> 00:47:08,020 if you want to read more about the paper 1191 00:47:11,970 --> 00:47:10,089 that goes on here I have linked it into 1192 00:47:13,710 --> 00:47:11,980 the google event page I'll make sure it 1193 00:47:15,810 --> 00:47:13,720 gets put up onto YouTube and I'm just 1194 00:47:19,230 --> 00:47:15,820 about to tweet it out the you can go to 1195 00:47:21,050 --> 00:47:19,240 to archive and take a look at that paper 1196 00:47:24,060 --> 00:47:21,060 as well if you want to do a little bit 1197 00:47:26,880 --> 00:47:24,070 deeper digging into to the science 1198 00:47:28,319 --> 00:47:26,890 that's there good yes thanks for ya 1199 00:47:29,730 --> 00:47:28,329 thanks for reminding me about that so 1200 00:47:31,200 --> 00:47:29,740 deaf or them if you want to read the 1201 00:47:33,270 --> 00:47:31,210 actual paper there's a link to it as 1202 00:47:34,530 --> 00:47:33,280 well as the link to the press release on 1203 00:47:37,890 --> 00:47:34,540 Hubble site org 1204 00:47:40,230 --> 00:47:37,900 to learn more as well so that's it for 1205 00:47:42,390 --> 00:47:40,240 this week everybody next week Carol 1206 00:47:45,329 --> 00:47:42,400 Scott and I will be meeting with we have 1207 00:47:47,849 --> 00:47:45,339 another in our series of Hubble 25 1208 00:47:49,470 --> 00:47:47,859 hangouts to celebrate the 25th 1209 00:47:50,700 --> 00:47:49,480 anniversary of Hubble we'll have Carolyn 1210 00:47:54,390 --> 00:47:50,710 Collins peterson with us to talk more 1211 00:47:56,700 --> 00:47:54,400 about the illustrious history of Hubble 1212 00:47:58,020 --> 00:47:56,710 and as we as we said the last time we 1213 00:48:00,240 --> 00:47:58,030 did a history of Hubble hangout we're 1214 00:48:02,579 --> 00:48:00,250 gonna be doing many of these so because 1215 00:48:04,170 --> 00:48:02,589 25 years is a long time a lot of stuff 1216 00:48:06,599 --> 00:48:04,180 happens so we'll have her next week we 1217 00:48:10,130 --> 00:48:06,609 hope you'll tune in and and check us out 1218 00:48:17,250 --> 00:48:10,140 I'll create the events tomorrow and I 1219 00:48:19,650 --> 00:48:17,260 keep getting animals that isn't alright 1220 00:48:32,370 --> 00:48:19,660 are you going to the danger zone 1221 00:48:35,120 --> 00:48:32,380 yeah but you you probably you always 1222 00:48:38,069 --> 00:48:35,130 have a fun day with that ringtone yeah 1223 00:48:39,359 --> 00:48:38,079 danger zone okay everybody thank you 1224 00:48:42,809 --> 00:48:39,369 guys for watching we'll see you guys