09:00:14 Okay, um, it is 9am pacific time. So let's convene the panel, um, I want to make sure that we have all the panelists here and they are able to participate.
09:00:21 So, if you are a panel member, like, it's Chris here Chris out.
09:00:29 There he is.
09:00:29 Turn your camera I see you there Tina I see you admin, I see you. And then I saw Fraker earlier.
09:00:38 And there she has she's out in fact, she is raising her hand she is at the head of the admin resume grid.
09:00:47 So I'm actually how about we let's Franca has her hand. Raise so we will let her ask a question first. Joe was first though but thank you. I, so I, I'm very glad that you got to the medic fields parts and, but I am not very good.
09:01:06 I have a question about this because I'm not very good at observational coordinates. So, what I saw was like, from the h1 that it was all oriented in the same direction and my question to Mary is like which direction is this over what kind of scale, like
09:01:23 physical skill was that and what does it tell us about the flow of gas and CGM there.
09:01:31 Yeah, I wouldn't I wouldn't say that we, I would say it was on the same direction we did in the lowest velocity part of that I BC, it was going in the same, the filaments were going the same direction but then for the highest velocity we actually saw
09:01:44 them start to go in another direction, but I would say this is early days, and saying that the filaments are definitely tracing the magnetic field we've known since we first started taking observations of HVT is the measuring system stream is a prime
09:01:59 example that h1 clouds tend to have this kind of overall large scale elementary structure. So, but I think it's an interesting possibility given what we found for the each one filaments in our own galaxy that we could have a continuation of mapping this,
09:02:13 and then in terms of this is all lower Halo. Same thing with the rotation measure results. This is lower Halo. And in terms of the flow, I can say we did look for signatures of flows along the filaments to see flows along field lines, did not see that
09:02:31 across your magnetic fields will be oriented in the same direction as the flow of gas, yeah and and so we looked at that we're not finding, actually we haven't looked at large scale book flow too much we so far what we've done is, we're looking for flows
09:02:49 along the individual filaments which you might expect right and we're not seeing that. And we have, we have point one eight kilometers per second resolution right 180 meters per second resolution so it's pretty good.
09:03:04 and we're not seeing clear flows on the filaments.
09:03:08 Thanks.
09:03:11 Okay, Joe, I'm going to have you asked your question.
09:03:15 And feel free to ask to the panel as well.
09:03:18 Thanks. Yeah, so I brought this up in the slack just now. But on the point of the Milky Way that 31 dwarfs being, you know, perhaps more gas core, and more likely to be quenched, and those around other galaxies in your representation of the Milky Way
09:03:38 to 31 systems Mary, you had it looked like the dwarf galaxies we know about are actually pretty strongly clustered in this sort of inner regions of, you know, the respective halos.
09:03:52 And so I'm just curious if if maybe, and anyone on the panel can comment here but if maybe the fact that those those dwarf galaxies are have have, you know, gone further in their info.
09:04:06 And perhaps have, you know, undergone their impression pressure stripping, more so than satellites around other systems, and maybe it's just an evolutionary dynamical state thing.
09:04:20 So in general, we don't consider the local group a highly evolved dynamical state it's not settled So, uh, but your question is just that the satellites originated earlier somehow in our system that they've had more time to undergo the stripping process.
09:04:39 And so this goes back to the comparison with simulations and so there's work for instance by Christine Simpson and and there's some others as well it's not coming to mind but where they actually look at the simulations and what you expect and indeed they
09:04:54 do see that stripping is common, and that that you would reproduce that type of result. The other thing they find is that there are lots of what are called splashback galaxy.
09:05:18 So, the ones that are beyond the video radius without gas they can easily be explained as ones that have come in and been stripped and they're now towards the edges there so that could even explain those ones that are strip that are towards the outskirts, so I don't think I'm quite answering your question actually good Tina Do you want to comment on
09:05:22 this.
09:05:23 Yeah, sure. Like I don't think there's any evidence that the orbital properties of the satellites around the Milky Way or and 31 are particularly odd.
09:05:32 As a population. So, you know, it's not cleared why these two systems would have the dynamics are set everything stays in the very center, and then all the other ones that we're seeing with the saga survey for example have completely different dynamics
09:05:45 that would cause the difference that that would explain.
09:05:51 Yeah.
09:05:54 Can I follow up on this a second so much, the fact that in the Milky Way you're counting also extremely small galaxies like they would have faint words that you will never see probably in this survey so much that much different does it make.
09:06:14 Yeah, so with saga they actually did an accounting of the ones in the Milky Way that are detectable by their survey right and so that's the same thing we're doing with looking at other systems now with doing now, we're looking at what we can detect in
09:06:28 these other system and once you take that population, the ones you can detect How do things compare. And so even just taking the ones we can detect we're finding differences at the local group dwarf galaxies are more quenched.
09:06:42 Can I can add something really don't. But there's another issue and that's it. You've shown nicely. If you go outside of the variable radius and you're looking out to feel feel very radio, you see a lot of gastric galaxies.
09:06:55 And in the saga survey, they will not be able to discriminate those from galaxies that are inside of the radius during the info pattern they have exactly the same line of sight kinematics.
09:07:04 So, doesn't that just explain the situation in the Milky Way were specifically counting things out to the very radius but we should probably be counting everything that has the same line of sight velocity.
09:07:15 I actually don't recall how they're doing that exactly forgetting their distances, and do you.
09:07:22 I don't think they can.
09:07:24 Yeah, they just got it right I should look at that, that makes me think I need to look at that more closely because we're doing the same thing in terms of looking in each one we have to use the velocities for the satellite right and so then what we're
09:07:37 going to do is project the whole local group and see how many you would expect to detect and then indeed once you project the entire local group you get in those gaps just one so your point is exactly what we're considering now and I hadn't looked at
09:07:49 what saga does with that regard.
09:07:56 saga does with that regard. Okay, I'm going to take moderators privilege and ask a question I have, and then we're going to get to Joel and Smith.
09:08:05 But I think it's a question that they might play might like as well. And that is the milk, milk anyways hot Halo has constraints from being from extra mission.
09:08:15 Actually absorption Magellanic stream pressure equilibrium. And now, satellite stripping statistics from Marius recent paper, are we able to build a consistent model of the Milky Way hot Halo, from these headroom heterogeneous observational probes, and
09:08:31 this is for the panel as well.
09:08:34 I think admin would admin Do you want to take a first crack at them.
09:08:40 Yeah.
09:08:41 I mean I think that given the constraints that we have. It is possible to create a self consistent picture of the Milky Way hot Halo, and one of the main problems right now is that those constraints do not lead you to a unique solution for what Halo looks
09:08:59 like and, I think, to a large extent, we're very much still
09:09:05 at the point where whatever model you you assume that you when you put in is going to determine what you get out.
09:09:12 If you are using something that is primarily working with a lot of ambition line data, you're going to be much more
09:09:19 sensitive to what's going on in the desk and the disk Caleb interface, if you are using absorption, you're going to be more sensitive to what's going on at large distances if you assume that the Milky Way.
09:09:31 A hot Halo and the heart is on the desk or more or less a contiguous system, and you combine the information from absorption to extra binaries in the desk with the sightlines to a GM behind the Halo, then that leads you to yet another mouse model.
09:09:49 So I think that that we are able to use those constraints, and I hope that we will iterate it and reach something will converge to a single answer eventually but I'm not, I don't think we're there yet.
09:10:06 But I would like to highlight that the halos pay papers are starting to come out. This is a first astrophysics CubeSat, and I don't know if Phil is on the line but I think Jesse is on.
09:10:19 And so the the film published a paper on an analysis of the Southern Halo and one of the men results from that was the, the mission is really clumpy Jesse is now going to publish a very is working on a paper.
09:10:35 Analyzing the, the north and south.
09:10:40 Halo data and so I think that, like that's going to be a major improvement over what we got for Rosa. And I think that will help quite a bit in terms of the emission lines side.
09:10:49 I don't know if it will completely solve the uniqueness problem.
09:11:00 I don't know if anyone else wants to add to that I don't I don't think I have anything there.
09:11:10 Okay, but let Joel say something and then, you know, I think that's it.
09:11:16 Well, yeah like Joe.
09:11:19 You had your hand raised for a while so go ahead. Okay. So, let me make few points.
09:11:25 First, which you know I publish on 2018 is that there is certainly a difference between Milky Way, and cost halos which is 2.5 Giga years earlier in time.
09:11:38 But the Milky Way's and, you know, low, low ish columns that, that one season look the way isn't all that different than the low z galaxies that the cos team, you know stocking company published.
09:11:55 so it may be the blues just can more evolution in that regard than we thought. And the last two and a half gave us.
09:12:04 Moving on to something else. We do have a number of constraints on the Hot X ray meeting Halo the Milky Way It really only goes down to about 50 kilowatts sex.
09:12:18 And then, we're extrapolating.
09:12:20 But one of the new things, and you know we seem to see halos around other galaxies from SC workout and I'll put something on slack soon.
09:12:34 But one of the other things, one of the things that's come out that's that's revenue is from senior high school dovish observations of our local group.
09:12:44 You see a hot fridge, in the direction of between the Milky Way, and I'm 31.
09:12:51 This is also the direction we're allowed to offer such as the LLC and SMC have come through the density is higher there than in say other directions. And so you might expect more stripping so when you consider stripping models you should we don't we don't
09:13:08 have we looked into this we don't have the data to say what the orbits exactly are doing we tried to see if they did preferentially pass through that entire region and me.
09:13:17 Yeah, you can't say that. Okay, well, I thought you could for. I mean, I mean good Tina could say a lot about this actually we should yeah you know so Monica for Lori, who's my expert on this.
09:13:44 that direction, based on proper mode oh sorry I thought you're making a general. No, no, No, no.
09:13:46 So in any case, that's all I want to say in other galaxies, we find that the hot, a low out to about $250 on sex is comparable to the stellar mass.
09:14:01 Okay, that's about it.
09:14:04 Okay, no question there.
09:14:07 Okay, I'm Ben up Should I keep letting you moderate, or I'm wondering what you suggest is the best way to do this like there's people raising their hands, there's a lot of questions in the chat.
09:14:20 Right in the slack. So, I guess, Um, what do you want to just encourage people to ask questions in the slack to raise their hand. Is that what you want to do and I think otherwise I'll just say and otherwise if I can see that just and young have already
09:14:32 helped answer questions so that's great and then I'll go in after this and make sure I try to answer any of those as well. And the panel. I think we want to hear from Smith, she's had her hand up patiently for a while, and then I'm going to try to get
09:14:46 some more of the panel members involved because we haven't heard from Chris yet and I definitely want to hear on the cool side of stuff to Andromeda. So submitted, go ahead.
09:14:59 Yeah, so I just wanted to say that I do agree with admin and things that he has said about evidence that we have from a mission in x rays and Halo sand and new Ito Zika results are really making a difference, but it is very important to keep in mind that
09:15:18 the column density as we infer from these regions which are emitting which are very density regions and compete regions are too low to explain absorption data, so there is no getting around the fact and feel.
09:15:52 did as a Ws special session, we had in June, is that there is no getting around the fact that the had to medium in the middle of a CGM that we see in absorption is very diffused and extended.
09:15:52 And I wanted to comment at your talk, maybe, by the way, great job. Great lot of book is that the, the, you will also suggest that there is actually a lot of podcasts as you showed by the by the gas that is required to strip the galaxy that you're talking
09:16:08 about so there is actually a lot of months in the Milky Way CGM, as we saw, and that that even the average density of the order of 10 to the minus four per centimeter cube is really reasonable it's very similar to what you actually get from Social Studies
09:16:30 also looking at competitors in over absorption ambition. So, I'm behind it is true that we do not have a unique solution yet. And I would be the first to admit that our understanding of even the hard to Milky Way CGM is evolving.
09:16:55 but we are very much coming to a consensus. And so, maybe what I wanted to say when you after your talk is that when you say there isn't as much Mars I think that is the qualifier oh cool and warm guys and that there is actually more mass in other ways
09:17:08 which is odd phase. So that was the thing I wanted to mention, and the other comment I wanted to make because you mentioned here look as is that I basically wanted to talk about.
09:17:22 You have work that we have been doing and that here I definitely want to talk about the work of sensibility does with my student is that we she's making new grounds with very deep hun data, and in next in the galaxies we are actually reaching the column
09:17:38 density of tentative order 16.
09:17:57 centimeters squared and so seeing diffuse low column density very extended gas out 200 kilobits six so that's that's a fun to talk about later 10 of those 16, you must be smoothing like 100 kilometers per second or something so that's that it's very tricky
09:17:58 but we should definitely talk about that later. Ben, why don't you go ahead to. Yeah, I'm Todd, I do want to get to Todd he has a follow up, comment to the hypothesis, but thanks Ben So just a quick comment on this idea that the Milky Way is different
09:18:15 because of time evolution.
09:18:17 Well the Milky Way is not the only galaxy that we've studied in the nearby universe I'll just give you one example. Dave Bowen, did a really nice study of NGC 1097, which is you know 10 or 15 mega parsecs away.
09:18:32 And he looked at not one but for Quasar sightlines behind NGC 1097, and now he has three more. And you can look at that paper in the h1 in the halo of NGC 1097 looks very much like the cost halos halos at comparable distances say 100 kilo parsecs.
09:19:05 Then, Todd sorry, does it have to have a satellite system through it or something because it is, it's very rare to detect those. The point is, and Chris made that point and one of the questions in slack I saw the high column Dempsey's at large radio.
09:19:18 I mean, you might get you definitely get Lyman off absorption and those local galaxies, but those types of high column densities. The only time you've seen that in each one a mission surveys is when there's a satellite system coming in.
09:19:32 Right. But of course, cost halos, which is what we were comparing to is not looking at those high column densities, so often much of the cost halos columns are are not detected, except the time.
09:19:45 But the massive those costs able sidelines is dominated by the very high quality sidelines. And so when we did the comparison with him 31, what stood out in particular was the lack of very high calm density systems like you see in crossing those.
09:20:01 And so, I mean, it is true that the, on the whole, a number of state lines of pro relatively high competencies might be smaller, but they really dominate the statistics in that sense, in some ways, so that that was the point of the comparison right.
09:20:16 I don't want to be contrary and maybe this is an interesting discussion that we can have, but I'm not sure that a high, each one column density reflects a high mass, because of course, there's a big honkin ionization correction.
09:20:29 So, if you see something with an H one column density of 10 to the 14. It's very hard to get the math, and I think maybe in all these things probably most of the masses in the ionized gas.
09:20:43 So, I'm not sure that absolutely.
09:20:47 may be, except that the silicon studio and things like that tend to scale with each one of course right so that does play differently, right, there's the, there's an ionization question, unless you can do the trick which customers have done, we've done
09:20:58 from, from costumes. So what is different in that regard. But the oh six doesn't change that. So I mean, I don't I'm not 100% disagree with you except to say that yes there are lots of ways to tabulate.
09:21:30 So I guess the main point that I wanted to make is that we can look at other galaxies besides the Milky Way in the nearby universe and. And in that way we can see if there's something peculiar about the Milky Way, which would be interesting in its own
09:21:52 right.
09:21:47 Yeah, I think that's something when I was thinking about this that I felt like maybe hadn't been done at the level that could be done in terms of taking all the local galaxies doing exactly the same census of mass etc and seeing what you got, because
09:22:02 there's enough archival data now to do that.
09:22:07 I'm Cortina has a comment or a question. Yeah, I just wanted to add in that when we're talking about comparing it you know at the right time so if some system for cost halos are at an earlier stage.
09:22:18 It's not just in terms of literal time but it's also in terms of evolutionary stage, so one thing to bear in mind is that, you know, the MC will likely merge with the Milky Way and about 2 billion years.
09:22:28 And after that it's expected that a lot of the properties about the Milky Way may become much more typical, the comparison to other comparable the mass galaxy so its stellar Halo for example is fairly low and middle St Mary's countdown had a really nice
09:22:41 paper which shows that you know if you add in the MC star suddenly bestseller Halo the Milky Way becomes much more normal. So there are a lot of properties that you know gave it 2 billion years.
09:22:49 Then suddenly in the Milky Way will be a different system and you'll be comparing to a different point so you have to sort of compare apples to apples most galaxies have an LLC type analog that they even at some point in the past if their Milky Way scale
09:23:01 it's one of the major building blocks.
09:23:03 And so you do see you need to keep that in mind, whereas the Milky Way hasn't actually had a merger with a matte object as massive as the arms in the past 10 billion years right so it's at a different stage.
09:23:17 That's a great point. I just put in a question in this slack.
09:23:20 Jonathan has been Jonathan CERN has been waiting patiently and I'm excited about his question.
09:23:29 Thanks.
09:23:29 Yeah. Hey, thanks. A yeah I have a question about the association between the six, and the H 1. million mentioned their talk. So it's right when we're looking at course halos right we see that the the relation between the next column and the impact biomaterial
09:23:45 is very different from when we look at the h1, or the low while and kind of the other six is much has much more flat relation with impact parameter which kind of suggested comes from much larger scales, then kind of the low ions in the largest ones calls,
09:24:02 it, then, where you kind of said that does this evidence that there's that they're very that they seem to be in the same place right that they did have those some strong association so I'm kind of trying to understand how to reconcile these two things.
09:24:18 If you have any comment on that. Yeah, I think I'll let Chris say more on this for sure but when we look at the Milky Way I'm just bringing up the plot but I don't think I need to share it again, it's just it's largely a very similar velocities and this
09:24:30 is a point Can somebody made in his paper that you see it overall follows the structure the h1 complexes except for there were a few interesting sightlines maybe local group medium which Richter is also followed up on the sidelines that don't follow the
09:24:44 overall structure of the h1 and other ionized gas components so you do which does indicate, at least for the Milky Way what we're detecting is stuff that is associated with the other phases and Chris, you might have even been on those papers you want
09:24:58 to say more.
09:25:01 Well, except I lost Johnson's question about halfway through, except, so I think even some of those six that was identified as sort of local group in that sandbox paper I've turned out to be associated with in 31 we now.
09:25:14 So, I mean there's certainly there but yes, when in general, you know, in the Milky Way the MC in the sight lines between the Milky Way the MC.
09:25:28 If you look at the the extreme of the six absorption it's always within the extreme of the oil.
09:25:43 velocity. But that's. I'm guessing it's kind of what the question was just based on marriage. Yeah, yeah. So, I mean, at least for Costello's It seems that the oh six is more distance than the low ions in the knowledge.
09:25:52 And so I just thinking is this, this, a correspondence in velocity, does that necessarily tell us that co spatial, or maybe it's just some large scale willows the structure and the Halo.
09:26:08 Always difference between the Milky Way and Crusaders are in it. That's the only two possibilities, I can see.
09:26:15 Are you thinking, just so for clarification you thinking the oh six specifically associated with for example, the, I will see clouds in majorly extreme and such, or just more generally everything that we see
09:26:29 here you are thick or thin right the last is always seem to be correlated with the velocities of the h1 right that's that.
09:26:39 Yeah, for other systems just do you want to see more on this, in terms of the location of the or six.
09:26:46 So I was going to chime in, I mean can automatically that's absolutely what we see around cocktails I think there's no difference I mean if you look at the kinematics of oh six in the low ions even 80% right I quantified this and 2016 80% of the low ions
09:27:00 and oh six are kinematic Lee aligned in terms of the velocity centuries of the different components, oh six looks different though there is a lot about six, it's broader.
09:27:10 And I think that the difference Jonathan I think part of it is ionization state. so when you're just looking at both column density trends with impact parameter.
09:27:17 I think that there might be some kind of ionization transition, like in the halos and density transition to that happens around like 75 kilo parsecs or so oh six doesn't drop off nearly as quickly as the low ions but it's hard to, I don't think you can
09:27:34 make the jump than that oh six is coming from larger.
09:27:37 You know actual distances from the galaxy.
09:27:41 But if it's the gulping as fast within back Bahama, doesn't that tell us that it's located followed it away, or think some of it is looking for well maybe you're not seeing the low ions because they've transitioned to a higher ionization state, right,
09:27:57 yes right other words, to it in two or three that you would pick up at 50 kilowatts six might be just so weak, relative to the or six doesn't necessarily mean they're not coming here they're just going to drop off different, so it doesn't exclude that
09:28:10 I would say but Todd you know has shown me show the other day last week, two weeks ago, lots of examples of that sort of consistent with what Jesse's where it was six and lawyers are very well correlated now in velocity.
09:28:25 I agree with a correlation with velocity I guess I'm just the fact that the oh six doesn't talk with impact parameter cancer to me suggests that it's far away, regardless of where the lines are just the fact that it's a flat relation.
09:28:37 If you just do project that without any assumptions.
09:28:41 Too much, too much assumptions if you do, you get to do six.
09:28:46 I think is more distance or at least most of it.
09:28:50 So maybe I'm maybe I'm missing something, but that's kind of my impression from Full Sail, it's not just the velocity extreme it's also the component structure and Glenn has showed this and I've showed this that components go up and down and each one
09:29:04 and the components go up and down and oxygen six and the centroid strike along.
09:29:09 And in that statement that Chris made can be applied in a lot of contexts, we see that in the Milky Way disk, the extreme of the low iron absorption in the Milky Way disk is the same as the extreme of the oxygen six.
09:29:23 I think it's very strong evidence that oxygen six has some kind of profound connection to the lower ionization gas. I don't think it's volume feeling I think it's some kind of interface phenomena or the other things that folks like drama and and Max and
09:29:48 Evan, and all kinds of people have been talking about the volume filling phase, I'm guessing is what we see and oh seven and eight. And maybe X ray emission I, I believe there's a hotter phase that we just don't really have access to when we look at ultraviolet
09:29:59 absorption lunches.
09:30:13 the high and the old six and below that.
09:30:15 What kind of puzzles means the very different relation between column, and inbox.
09:30:32 Between those six in the lions, and that's hard for me to explain in kind of a cool spatial picture, if, if, if it makes sense we're always six would exist wherever those little ions and vice versa, they would have the same relation.
09:30:35 Think dance and be clearly dogs. Yeah. What I think is happening is, is that, as you go farther out the stuff becomes more ionized.
09:30:46 Maybe the densities drop or the physical conditions change. And so then when that happens, the only things that are really sensitive enough to see the material are oxygen six and eight one and and the other ions just become really hard to see.
09:31:01 It could also be metal a city effect but that's my guess. I mean, I agree with your point. It is, it is an important piece of information. So, okay, this conversation along I see corral patiently raising his hand and we want to hear from new people, so
09:31:18 please ask your question.
09:31:21 This is actually also about the same subject, but this is a specific case for the Milky Way where you can kind of test this out.
09:31:29 So, there is the, this is actually sort of a classic Kalkan linear reference.
09:31:38 There is the, the, ah, there's, there's a big kind of HPC or possibly probably multiple HPC is at this point. Seeing towards the large metal on the cloud, right there's oh six, and this is seeing towards you know, 10s of stars almost 100 stars in that
09:31:54 direction.
09:31:57 Now, there's those experts, most of them, if I remember correctly, from those papers.
09:32:02 But the interesting thing is it, as it's turned out at least some of that HPC is most likely actually quite close, there's a very funky white dwarf. That was found in that direction, which shouldn't be very far away.
09:32:19 And I would have to dig into the papers to make sure, but I think the six properties of the two of sort of the the part that's probably in front of this star, and the part that is possibly farther away and actually close to the MC do six properties are
09:32:40 pretty comparable.
09:32:42 And so in that sense right that that's got to tell you some of the basics can be very far away, and going very far away from you know from not very far but you know going 4040 kilometers away out to this and so the MC or so, versus going in that maybe
09:33:02 10 kilo parsecs away that's sort of the distance to this white dwarf doesn't make a big change. If you're looking in the Milky Way. For the iOS six. So, at least in the Milky Way It seems like the iOS six is quite possibly not very far away.
09:33:16 Better go straight to Trulia, and you also have it along the entire management system where we think the tail goes out to 100 kilo parsecs right so we, so that's actually done within the Milky Way data so it may be useful for one for you to think about
09:33:28 more given we have what grills and what krill described as well as the management system which probes what's going on with those six in the outer Halo.
09:33:42 Okay, I want to switch gears and address, Greg Brian's question as, is there a consensus to the origin of the high flashy clouds. And are these a significant contribution to the Milky Way mass and angular momentum.
09:34:03 And the origin, no.
09:34:06 So, except for the meddling system it's still the same that there isn't consensus and metal the cities are, you know, range point one 2.4 you know depending on where you are in sky there's a lot to be done yet with middle of the Seas actually I think
09:34:25 by rockers work and some data related to that and and so. So no, I, we don't know i mean it could be gas that's recalling closer to this now that we know it's all closer to the desk and it's maybe a mixture of all the different guests I'm imagining stuff
09:34:35 that's come down, you know i and i is and then it gets closer to discovery in Serie cool out, we don't we don't know the exact origin, mass contribution is no I love just had this pie diagram where she used to make fun of that like he sees zero percent.
09:34:50 So, So in terms of their mass contribution it's negligible.
09:34:55 That's talking about the h1 and when you bring in the ionized again because they're all close to the disk and still not much when you bring in the ionized, given that they're all here and most of the master would be, you know, out here in the large volume.
09:35:09 Yeah, the is guess is 10 times each one, but when you're multiplying zero by 10, you don't get much right.
09:35:19 And that's even true if Sorry, just to quickly follow on that's even true if you account for the fact that it's close to the distance so presumably accreting rapidly so may not exist in that state for very long.
09:35:31 So it's like a flux question.
09:35:35 Oh, You mean in terms of the info rate they provide.
09:35:39 Yes, exactly. Okay. So it depends on how exactly you do the info rate but you get about point two to one solar masses per year.
09:35:50 Given their low z height and relative velocity, you have to make some assumptions about their 3d motions with that.
09:35:57 And then the metric system is a whole separate one as good Tina mentioned that's going to be you know Milky Way is going to love that you know it's having a feast once that comes in, but that does not include thinking about the measuring system.
09:36:09 Yeah, you could argue they are significant in terms of their providing a decent amount of ongoing fuel, if they're continually, they have to be continually reproduce so that's key, you need to continually be cooling out the material because we don't see
09:36:21 it other ways besides some magic system.
09:36:24 Could there be info coming from the display that we can't see because of our solar perspective.
09:36:31 Yeah, that's an interesting question that at high velocity but you might not expect it to be in high velocity once.
09:36:38 the blog put out with a student for NBC 2915 where they are seeing some flows along the radio access. Get along the major excess of galaxies, and for the Milky Way.
09:36:59 I haven't heard anyone try to make that claim yet girl Do you have any insight into that
09:37:07 flows in the plan of the Milky Way. Yeah, going inward word, the gap.
09:37:13 I think, Josh, wrote a paper where he tried to look at that.
09:37:16 But I think the signal is to would be very weak. I know right there's been people people have looked for this in other galaxies so I think Tony Wang has a nice paper, looking at each one but maybe I think probably h1 dynamics and a few local galaxies
09:37:39 like trying to decompose the velocity field into a variety of kinds of flow. But I think they're the conclusion was that, first of all, it would be pretty degenerate with other kinds of motion, other kinds of non access symmetric motion, and the constraints
09:37:48 that yeah the constraints that cannot aren't like super great. Exactly, yeah.
09:37:54 regulation is this this problem and people asking that goes back decades, and they always seem to have sort of limits with AC can't quite do it we don't quite see it.
09:38:04 Maybe that's the wrong impression to, so I guess there's
09:38:10 a few solar masses per year flowing regularly in the desk right.
09:38:17 Yeah.
09:38:22 That can add a couple of things briefly, I'm going to discuss these things in my talk, but just just that we are mentioning this so the the maybe inflow within the Galactic fountain cycle, so that we see in terms of intermediate velocity clouds.
09:38:36 We were and i mean i i tend to see these days. This is the last the clouds like an extreme version of intermediate velocity clouds I don't think that somehow there is a divide between the two decided by Bob Barker 20 years ago or what was it 30 years
09:39:10 ago. So, so, I mean, the maybe it should be much more inflow there. The other thing that I wanted to say is, is that in external galaxies especially several people tried to manage to measure the radial velocities in the desk to see, there is this radial
09:39:17 inflow and usually the values are very low, or you don't see it. So it's the, there isn't an evidence of, really, I mean, discs behaving galactic this meeting like efficient that creation discs, let's put it like this.
09:39:37 So we are talking about one kilometres per second to want to do something like this, if it's there.
09:39:47 Okay, um, I'm going to switch gears a little bit because john Sean has a great question and I'm really interested in this.
09:40:00 Could there be any recent impact from a gn activity in the Milky Way setting the CGM ionization state in the Milky in the Halo, and we think about the Fermi bubbles and the Rosita bubbles and RRCJ star central black hole.
09:40:21 So I post that to the panel. Yeah, I realized that something I did not catch on and I haven't followed that literature as well so I can let other people answer them I understand was it doesn't go out that far.
09:40:33 But when I don't know if Chris or if we want to bring in wrong man or something to answer that further Chris you want to start.
09:40:42 Or maybe admin, just, yeah and then might have a better idea, we've been freaking in terms of the simulation work but but my, so it might depend a little bit on what we're asking so just by and Hawthorne has been talking about the idea that there are
09:40:54 ionization in consistencies along the mental extreme that could impart be caused by elimination from an AGM.
09:41:00 And that would be really good feedback, so that that's sort of that seemed not unreasonable when I read it and they have some good evidence for it, and it's maybe not a solved problem, but I'll let others weigh in on perhaps the mechanical aspects of
09:41:12 it because they would know definitely.
09:41:14 But, so, so within the radiative feedback is what I'm what I'm kind of implying by all this because yeah so you're thinking essentially like like in the precipitation case if you get a case where you turn on that IGN and illuminate the CGM so that it's
09:41:28 in a state where it's not likely to cool and condensing unless we can see it perhaps in the, in the UV torture that we see for example, and you know that that's potentially possible I don't know.
09:41:40 I mean, the mental extreme potentially provides just because of the time delay for recombination and also for when you shut off the agent for that information to propagate out there potentially provide some something of a handle on it.
09:41:52 Now as to whether we could say, you know, there's other evidence for that.
09:41:56 I truly don't know aside from I mean that could be an argument that you make for the differences, I suppose.
09:42:03 Yeah, I guess I can just say for the stream yeah we've puzzled about this bright region of the stream that's right above the pool but that's also a region that has this interesting cross complex of clouds and stuff like that I mean when I was a graduate
09:42:18 student I pointed out to justice and look it's right above the galactic center maybe there's some, and he dismissed it at that time then the Fermi bill came out.
09:42:26 Now he thinks that you know it's out of him there. I also was wondering about the timing of this I don't know Christina if you're thinking about that time skills of the system and it being exactly overhead does actually work out correctly that the bright
09:42:39 patch would be there.
09:42:42 The closest approach of the LMT to the Milky Way was 50 billion years ago.
09:42:47 So, in order for the stream to be in that location you have less than 50 million years so as long as the time scale was within that there could be some overlap and scale is a couple of million years so it works out very nicely, but it's a very localized
09:43:02 effect in the sense that it's very directional with the sort of the jet, if there was one from the phone bubble point for it so I don't know if it'll affect the whole of the Milky Way.
09:43:12 I'm going to say something about the regular feedback because you know Joss if he drops would be talking about if he was here, and not asleep right now but his 2016 paper with Phil Maloney I think was fit, explaining the 90 crewman effects of each alpha
09:43:28 in the stream being enhanced by a Seaford burst of like several mega years ago, and then his more recent 29 paper 2019 paper is I think carbon foreign silicon for and, you know, I've worked on the you know the non equilibrium effects of, you know, flash
09:43:43 ionizing something in the Ag and turning off. And, you know, you could have a see for burst and the timescales would be a few mega years for like things like carbon for silicon for auction sex for those to last residual in the halo at elevated levels.
09:43:59 So, just been since you're talking about that was great.
09:44:04 You know, I suppose one question though becomes. Is it possible I mean with the narrow opening angle that might be suggested by the, what we see in the stream.
09:44:13 I mean, can you affect the whole of the halo like that.
09:44:17 In order to suppress something like oh six or the lawyers or something.
09:44:20 I mean, like, you know, how you know how much of the you know what's the opening angle of the Ag and radiation escaping. I mean that goes through like you know tourist models around the AGM.
09:44:31 I think you can definitely, you know pretty much come up with any, any sort of model where it's like, you know, you know, to pies to radians, or.
09:44:53 You have a little bit of information from the properties of the stream and the angle of which That's a fact. And that was, that was an Joss's 2019 paper.
09:44:57 So I think that one point on this is that if the Fermi bubbles were created by a person such a star which is my personal belief is that that's the best interpretation.
09:45:10 You know that limits the the age to within the past I don't know like a million years based on most of the models and, and that's fine but we don't know if this was a one off we don't know how often this happens, and in order for the Milky Way's whole
09:45:24 Halo to sort of be perturbed to the point by the ionization structure to be continuously perturbed by AGN, then we've been sort of need for me bubbles to be happening on a regular basis.
09:45:36 If these bubbles, always accompany the radiative feedback as well. That is, if the AGM turns on to every 10 million years.
09:45:47 And, and dumps out a lot of ionizing radiation then maybe you can explain some of the halo ionization ratios that way. But in that case we would also expect to see sort of a cascade of Fermi bubbles that those things.
09:46:01 As long as you always get mechanical feedback along with the radio feedback. So if everything is like a forgivable type outburst, which may not be, and there's there's not really any evidence for that these bubbles are going to continue to expand.
09:46:14 We kind of understand their expansion rate.
09:46:18 In a couple of wavelengths, and you know if if you were to produce these things every 10 million years every 20 million years, we ought to see more stuff piling up than we do in like the Rosita maps for example.
09:46:31 So it seems to me that there has to be a fairly long time period between outbursts, so if there's an ionization balance changed due to the, the outbursts that created the Fermi bubbles.
09:46:43 That is probably not how the Milky Way quote unquote normally is.
09:46:49 Can I have a quick comment.
09:46:51 Sure.
09:46:52 So I think there is some evidence for things being different around the shells right into because, you know, we definitely see a lot of ambition around the show so for me, an eternity debit well but I think we are also seeing different temperatures like
09:47:08 everywhere else that we see xa gas, we do see a few million degree gas, but around the shells we have very clear evidence and in guys that we see in emission.
09:47:19 let me qualify that again, it's the emission. We also see a hotter temperatures closer to 10 million killings. And so even therefore in these countries.
09:47:39 We see multi-phase gas and that gas is very much around these bubbles, which is not necessarily restricted to those regions, but we definitely have very clear evidence so high temperature guys around those shows and there is higher emissivity in those
09:47:48 guys also so there is definitely impact because in practice down ization violence, we are seeing ions we don't see otherwise like me on 10 right so that it yeah has, has the feedback from a gn are established activity I think it should be bad but anyway
09:48:07 that's debated is that affecting the organization violence, it definitely is because we don't see those islands everywhere else. Okay, great. We have about 12 minutes left and Daniel has has has had his hand raise for a while so we're going to go to him
09:48:21 him next and then Tim Hackman has his hand, and we're going to try to do those two questions. So Daniel. Go ahead, go ahead. Okay, thank you. Um, I have a couple of questions let me go first one.
09:48:35 Me, I caught it and I have been trying to do some observation me up absorbers united studies to understand. See, gas in the local group.
09:48:50 And I'm sure a lot of people are more people are working or have been working on this issues. So you have it was different distances, for example, to the M 3331.
09:49:10 So, to some of the other galaxies.
09:49:06 And so you have absorption eyes so whether that means to differentiate on the absorption line studies at large distances will be able to tell you about the actual local group, gas, and also what actual actual get an update our views, at any consorted
09:49:29 evidence points to not only is it gas about individual galaxies, but also at a much larger scales sent to the public around the center of the local group.
09:49:45 So your question is what evidence is there from absorption let
09:49:52 me, let me say off by the number of studies, towards the end for this free towards MZY towards a different other galaxies. So now, actually, more or less points to towards the cross the center of the local group.
09:50:09 Yeah, specifically those, and I mentioned the ones, no result and then Joel mentioned the recent result that I haven't looked at that paper yet indicating there is something there.
09:50:20 otherwise in terms of the up. There's certain absorption lines that don't seem to fit with the rest of what we see for Halo gas and and so people have pushed on those that's potentially representing a local group medium, but along that access particularly
09:50:35 there hasn't been strong evidence the Oh, the only other thing is the h1 codes that have been found in general though those are thought to be interactive debris probably like with them 33 in the past.
09:50:47 But that was for some time that was also noted as something unique but it's not. We don't have solid evidence between us and the empty one part of the problem is making that claim is difficult because of the velocity confusion when you're in the local
09:51:02 group to make that claim you have to do some very heavy modeling and people have to trust your model.
09:51:10 And so it's just very difficult to make a claim that everyone jumps on the bandwagon. So that's it, the simulations and simulations. Do you expect from from theoretical point of view, do you expect large scale diffuse, say hello, a local group gas.
09:51:33 Yeah you do that's in the simulations I'm Ben you want to come at you're doing group simulation.
09:51:36 Yeah,
09:51:39 not that type of group.
09:51:43 I think it'd be really difficult for the absorption line perspective, because of the influence of the guests that might potentially be around those galaxies themselves it's hard to disentangle that fast rivers might be and that is pretty much as you get
09:51:55 towards them might be the way to do this ultimately when we get enough of them.
09:52:00 The local group bear center is not exactly in the direction of in 31, you know, so maybe you can look for upsets and build up a community that way.
09:52:08 So, yeah, but it's I'm with you it's a hard question when be great to see the answer to.
09:52:17 Tim has had his hand up for a while so let's hear from him.
09:52:21 So, I'm not really convinced that the Euro see the bubbles are driven by an AGM. If you look at the energetics it requires about 100,000 supernovae.
09:52:33 If it were driven by a star formation. So that's kind of the seven solar masses and stars formed over the dynamical ages about 20 million years so that's it says if you have a half a solar mass per year forming in the central few killer parsecs of the
09:52:50 Milky Way, that you have enough energetics to drive this thing. And if you look at the Rosita bubble I don't really see any evidence that it's has a source it's very compact it's quite broad at the base where it intersects the dis so it could be driven
09:53:04 by the three kilo per sec ring of star formation.
09:53:09 So if there's. What am I getting wrong here.
09:53:17 Guys jumped in a car to go ahead. Hi. So, if you wait I am going to actually discuss this tomorrow.
09:53:25 You know, broadly and I think what we're saying I will test our function driven model can be true.
09:53:30 And I have written a few papers on this, which exactly matches your numbers, but I think this is still debatable so maybe we can discuss this. After tomorrow's tutorial in more details.
09:53:44 Sounds great, from other people.
09:53:47 I think this was justice model to in the early 2000s. Yes, yes, yes. Yeah, I think, yeah, I mean it is pretty centered, it seems like on the you know the very center of the galaxy, where Sanjay started as opposed to like three color parsecs out but I
09:54:05 don't know how that that's not necessarily I mean if you have any can have hundred percent stuff from from the original hundred percent that would work well they're just to chime in on this i mean i i don't have an answer but there's good, there is no
09:54:20 evidence for an X ray chimney from the, from the subject so I region, pretty locally, that seems to connect up to the Fermi bubbles whether or not that's just something that happened once they were already formed or whether or not it's the driver I don't
09:54:34 know but there's a lot of xmm time just awarded to study this further so I think that we're going to get more insight onto, to the extent to which there is like an X ray Chad is has been claimed, and we might get more insight into the origin of the variables.
09:54:53 Yeah, but I mean certainly Sanjay stars not doing anything very dramatic right now with over the last 20 million years Sanjay stars is active as it is now, it could never have driven fairly bubbles it had to have been some explosive sort of event that's
09:55:07 not happening right now, right, actually, but if you look at the reflection spectrum from the like the the the fluorescent iron k alpha and round such a star with it I mean this is that does not go back, the 3 million years needed to produce the Fermi
09:55:23 bubbles but we do know that within the past 500 to 1000 years surgery star has had near Eddington outbursts for loved ones, but you know, not conceivable that it had that something happened and it had a big outburst, and now it's quiet.
09:55:39 All right, well I've obviously stirred up a hornet's nest here but be good if we can talk more about it tomorrow. We did I miss that 500 to 1000 years it's been at Eddington.
09:55:55 No, no, within the past 5000 years so if you look at the, the, the X ray emission lately iron KL for the mission from molecular clouds and other galactic center, you can work out from their distance from the kinematics with their distances to such a star.
09:56:05 And so you can say okay well if these things are this right now, and you assume a nice a tropic
09:56:12 radiation field from Sanjay star and you know the distance, then you can work out. You know how long ago, it was a bright. And if you do that then you get up, I don't know if you get to Eddington all the way but you get pretty close to Eddington for.
09:56:26 I'd like that was minus for adding content to underscore Eddington.
09:56:30 You're talking about the estimates by this Japanese group right. So, that was closely linked into an s3 to invest for reading can there. Yeah, for the most part, yes, but I think that there are a couple.
09:56:45 I mean, to some extent, I don't want to derail this too much but to some extent it has to do with how you model, the fluorescence, but for some yield models like not all the outputs get up to Eddington, but, like, a couple get pretty close.
09:56:59 So I think that, you know, if you if you build up the light curve of of what you think such a star was doing it has some pronounced peaks in it and then now it's like 10 to the minus nine.
09:57:11 So regardless of what has actually happened. I think that there's pretty good evidence that it can have dramatic flare ups and then return to this extremely quiet level which is way below almost any other black hole that we know.
09:57:26 I'm a comment obviously the beta. I mean, obviously it's relevant and the Ferguson radiation on me. You can kind of fill in for something like a 10 to 39, bucks per second in terms of radiation so this is a very tiny, in terms of for edit and ratio.
09:57:45 And as the current quite quite nice of the said you're a star is mostly due to because of the young stars around, which you produce a very hot the wings.
09:58:10 Basically, prevent the coup gas into close to the into the black hole that's quite reasonable. Understood.
09:58:04 And it because the age of the customer is about a few many years. So you can imagine Wednesday customer of a spa was a forming. And you could trigger the set a spa activity, I think that's a timescale wise, about right.
09:58:20 And so, in terms of the chimneys extra chimneys at this right now because, which is a much smaller scale compared to the Fermi bubble and an assist structure is very local Andrew easily understood by the feedback from stars couldn't stars in the in central
09:58:41 region of Ghana's data center.
09:58:45 And, but actually I seem to see see strongest evidence for the central origin of with a phobia bubble or whatever, you know, see the bubble is actually I think the absorption I study, which indicates a few hundred at least a few hundred kilometers per
09:59:01 second that expansion that automatically declines the huge amount of energy. I think we have seen, at least in my mind has gave us the strongest evidence, which is not is due to central region could have explored another due to some local can have for
09:59:23 See if you can apply six away from us, because normally Super Bowl will not expand this at this point, get Daniel will talk about this more tomorrow, and we have one minute left krill has one more question or comment and you'll be brief, and then we will
09:59:41 disperse.
09:59:42 Okay, I'll try to keep it brief. And I guess we can discuss it on the slack afterwards if people interested.
09:59:49 So this is a very different rates and taking things in a different direction. So, we talked about sloshing motions of gas in other healers, right, whether that, you know, as a way to, because it's seen in clusters because it's hypothesized to maybe explain
10:00:06 the structure of kinematics and Galaxy size halos, etc.
10:00:12 So the Milky Way seems to be an example of a system where we've not that way but like, you know, other people who actually work on this have detected splashing of, let's say the halo relative to the galaxy itself or vice versa.
10:00:28 Right, there's this.
10:00:33 At the very least, is just like Dennis circle and a spiritual result from this past year, showing the detection of sloshing.
10:00:40 Do we think that this isn't it.
10:00:44 Yeah. Do you think that that it might be possible, first of all to detect this kind of thing, do we expect that the sources of slashing to be related.
10:00:55 You know between the kind of non gas, and the gas.
10:01:01 And, yeah, that's where it's sort of a more of a discussion question than a specific question
10:01:07 that's that's a great segue to having that discussion.