09:12:24 Okay everybody, welcome back. It's 12 after the hour, and I would like to introduce our panelists to start out and in addition to our keynote speakers.
09:12:38 Aurora and Nicholas. I'd like to introduce Alexei Vic linen. If you can, like, unmute and just say hello Sorry dude unmute myself. Hi everyone. Hi.
09:12:51 And then, Rachel Somerville is here as well.
09:12:55 Hi. Good to be here. Hi Rachel admin Hodges cook is here.
09:13:02 Hello, Edmund, and Collin Hill, everybody.
09:13:07 Hi. Okay, so we are going to kick off our panel discussion and I have been looking at the slack, there's a lot of interesting discussion. I'm actually going to start with what Aurora suggested we might start with and that is the kind of surprises that
09:13:27 we can envision or that we might be able to imagine from x ray observations that are coming on line in the near term and long term, there's already been a few responses to the thread that I started on this to that I think are interesting from Ben and
09:13:48 Daniel are that accretion is hot in the present a universe and the other one is all hot gases out of equilibrium. This is from Daniel way. What do people think of these predictions and can we speculate about, about others.
09:14:04 That might surprise us even more I don't know it's kind of seems like a Christian being hot isn't.
09:14:10 I'm not that surprised by that but maybe I'm surprised. Why should I be surprised and panelists can feel free to just jump in.
09:14:19 And if any participants have something to say you can you can raise your hand. I absolutely love the comment by Danielle that's amazing and, you know, I didn't have time but I was sort of a little devil was on my shoulder telling me to open this kind
09:14:34 of warms and I decided not to do it.
09:14:36 But the fact of the matter is, you know, all of these things we are we are modeling as a fluid.
09:14:43 You know, and we worry about magnetic fields and we worry about cosmic rays but we don't worry for instance about something like you have a fully dissociated electron ion plasma.
09:14:53 Okay, and it's perfectly possible that, for instance if there's a shock going through that the temperature of the electrons is completely different than the temperature of the ions, and in these very low density things that stays this way for the guy
09:15:12 years 10 years even.
09:15:15 So easy okay that we are modeling this as a fluid, and I think the answer is nature is kind to us and the magnetic field equilibrate so electrons and ions and it's probably kind of not a terrible approximation.
09:15:27 But in certain situations so I don't think it's going to turn out that it's not an equilibrium everywhere, and that's good, but it will turn out that it's not an equilibrium somewhere.
09:15:36 And the question is Where are we going to define this and I'm really looking forward to that.
09:15:49 What about a creation being hot. What do people think about that.
09:15:54 So maybe I'll jump in there. And so the classic picture that we've all been learning for the last 20 years is that for low mass galaxies galaxies lower than the mass of the Milky Way, that a lot of the equation is cold right to these cold filaments.
09:16:09 But I think that Greg Brian showed some results from recent work by barrage Pandya analyzing the fire to simulations, in which that is not the case. So you can see the filaments in the dark matter, but the gas that is accreting into the galaxy is mostly
09:16:26 hot.
09:16:27 And that's due to the strong stellar feedback in those simulations. So I think it's a very interesting proposition that maybe this whole picture of cold accretion that we've all been, you know, sort of taking on board that may not hold up in the face
09:16:41 of these beads feedback models.
09:16:48 dan Do you want to say anything about that.
09:16:52 I'm going to leave it open for the panel and everyone here to discuss. I think it's quite different than the high redshift universes I'll say, I'll say
09:17:07 Edmund, I guess, I mean, I don't know exactly what we will learn about on occasion in the next, you know, five or 10 years, there's going to be completely iron cloud where it's no longer debatable like what is the most important thing.
09:17:31 But I think that we could be surprised in either direction, I think we could learn that hot gas is ubiquitous and slowly cooling and it's going to be important for the next 10 billion years, but right now it has very little impact on the Galaxy, we could
09:17:36 learn that that outflows while spectacular do very little to suppress star formation and galaxies and conversely, we could learn that they're extremely important.
09:17:53 Right now, like as if we go back to week two or three forget which one was not that was week three.
09:17:56 You know right now that the jury is very much out on the role of cosmic rays. And I think we're going to learn in the next decade, just how important cosmic rays are, and there's going to be ways to tell that both from the SEC as well as from the X rays
09:18:10 and the different to radio and other multi wavelength observations. And so it could be that, that our current view of the hot CGM is okay its massive therefore it is important could be overturned and into something where it's like it's massive but it's
09:18:25 not that important, or it's not as massive as we thought but it's extremely important.
09:18:31 The other thing going back to what Daniel said, I mean it could be that the podcast is all out of equilibrium. But going back to something I mentioned in the, the cousin talk yesterday.
09:18:42 The state of our knowledge about what the temperature and pressure of the hot gas is in a direct way other than from the RC is not very good. And that's because CCD resolution.
09:18:55 Most of the temperatures that have been measured around other galaxies, you can fit pretty much any galaxy with the same temperature model, and that model is not physical.
09:19:08 It represents some balance of hot and cool gas but it's really tracing a, it's a, it's a non unique equilibrium point when fitting a two temperature model to a complex emission Mr distribution.
09:19:20 So, you know, we may learn but the pressure of the hot gases actually substantially different than what we think it is especially close to the desk.
09:19:29 Within the next I don't know five to 10 years.
09:19:31 This is the type of thing that it could indeed lead to surprised about how important the gas is how the gas near the desk connects to the extended CGM.
09:19:46 So I wanted to relate this to one of the questions that I wanted to bring up. And that is, can we finally definitively answer the question of why star formation is inefficient and low bass galaxies.
09:20:01 So, you know, is it objective feedback is it because stellar driven winds are driving the ISS out of those galaxies. Is it because the seller driven winds are heating the CGM and preventing it from cooling, or is it because the CGM is perhaps out of equilibrium
09:20:16 and not cooling as efficiently as we might have thought so i think you know all of these possibilities have have been discussed now. And I think, you know, tying them into that sort of big question might, might be helpful and thinking about ways that
09:20:31 we can use the observations we've been discussing all week to really answer that question definitively that, that would be great progress.
09:20:41 I love that idea when you say low mass What do you mean by low mass, and anything in a halo less than 10 to the 11 solar masses or so, so not really extreme things you know things less than the mass of the Milky Way ish.
09:20:54 Yeah, yeah.
09:20:56 And so what are our prospects for actually, you know, the probing those halos and distinguishing between these different scenarios.
09:21:08 How far do you need to go in radius.
09:21:13 Belly far out but they're not very big.
09:21:17 So yeah, two times the variable radius of a 10 to the 11.
09:21:23 Halo right like that's that's only like 200 kilo parsecs or less even, yeah.
09:21:31 It's not going to happen in a mission. Absolutely. Ever.
09:21:37 You need, you need the mission that is going to fly outside of the Milky Way if you want to do that.
09:21:41 Okay, because, in terms of a mission the Milky Way foreground is already killing you. At virile radius of attend to the 12 Halo, and easy reducible at that point there is nothing you can do there is no way you can improve your, your instrument, and so
09:21:57 the only way you will ever be able to do this is in absorption.
09:22:02 And I don't know if you remember my plot.
09:22:07 All of the, you know, great things that are being proposed are empty triangles. And so we need to push for one of these great thing, X ray grading missions, if you if you want to, you know, to really do a good job and absorption.
09:22:28 I really think you need to go for that so
09:22:34 awesome. Fast.
09:22:38 Agree, could be could be interesting stuff to be done at smaller area as well, because I think right now we are in a situation where we almost have no data, you know, on the podcast and on long yes and those halos and warm ups and those halos, even though
09:22:58 the small radius.
09:22:59 Right. So, every time you bring up observational capabilities that, you know, holders of magnitude, compared to the state, you know, today you start learning new things maybe you will change direction.
09:23:14 So, you know, things like metal content of the outflows relatively small radio I can tell you a lot about the feedback moans, I suppose.
09:23:25 Right. And this is totally within the realm of, you know, maybe the non the very next generation of extra observatories but definitely things like links.
09:23:40 Okay.
09:23:52 Okay, so I'm gonna, I'm going to switch gears a little bit and move on to something that's generated a bit of a discussion. I'm Ben, Mark, and I think Joe have some related comments about the thermal pressure and the temperature profiles that Nicholas
09:24:11 showed in his talk and in particular, um, you know the comparison with simulation predictions.
09:24:18 So So Ben maybe you can clarify this discussion point a little bit and then I would love for Mark and Joe to jump in and then hear from the panelists.
09:24:28 Sure. Um, well I'm speculating here a little bit because it seems very, you know, the mo do results shows that that you know from the TLC thermals SC effect, and the KFC combined, you can get the temperature and the temperature looks very hot out at to
09:24:48 do for our beer around.
09:24:52 to four RV are around you know 10 to 13.5 So Ms groups of 0.6 and I know that TMG is too low compared to that and I would guess it, I haven't looked into this but I guess I would guess it's not the density but it's that, that the temperature that is too
09:25:18 and I would you know I'm sure that eagle is even, you know, with less less bearing on lifting and clearing and heating, probably is even lower. So I was, I was kind of surprised by how high the temperature was out there because I think of a declining.
09:25:25 You know, I think there's declining, you know, it's the temperature of maybe you would expect for the bureau temperature of these objects but at two to four hours here.
09:25:34 I would think that the temperature would be lower, a lot lower.
09:25:42 So, sorry, but one thing to keep in mind is that Nick correct me if he disagrees but I think you should interpret those as sort of a cumulative temperature profiles you're measuring some average of everything into your to that radius so it's not like
09:25:55 every point is independent.
09:25:58 So that can kind of bias here intuition about what's going on.
09:26:01 Good point.
09:26:03 But I agree with you, it's, it's definitely surprising.
09:26:09 What has got me thinking about when we do idealize simulations of agent feedback with narrow jets.
09:26:17 They can go out quite far.
09:26:19 And we know from the heritage of radio jet observations is some of them, the radio lobes are way, way out there.
09:26:30 And so, in a cosmological simulation, unless you have really high resolution it's hard to get the momentum flux necessary to drill out to high altitudes.
09:26:40 And so, so I this is not a fully formed thought, but it's got me wondering whether thermal ization of some of that jet energy happens at larger rate of the eye in reality than happens in cosmological simulations of the current day something to look into
09:27:02 for sure that mark this is well outside the variable radius. That's correct. This is, I think this is, you know, much, much larger than where you see radio lobes, much larger scales.
09:27:15 Well, mega parsecs.
09:27:24 More than that, yes, more than a mega per sec, I think, is that right Nick, Colin. Yeah, that's about right yeah right so radio loves are usually at hundreds of killing a large fraction of the radio lobes right but I guess the general point is, the farther
09:27:39 out the kinetic energy is one of the thermal ices, the higher the entropy of the resulting gas. What happens to it after that I don't know, but I'm scratching my head trying to figure out what makes things so hot It's such a large distance in thermal
09:27:52 I using the feedback energy at large distances seems to be what's necessary and I'm speculating about how that actually why that wouldn't show up in a cosmological simulation to current time.
09:28:05 When I was getting out of my with my question was, how much of it is, is it a contribution from structure formation and chuckling in. In, the large scale structure in the Corps of filaments For example, I mean it seems like we have to clean these separate
09:28:19 these contributions and experiment, right or
09:28:25 What was the expected contribution. Right.
09:28:29 A guy who has his hand up.
09:28:33 Yes. So regarding this point one the experience that we have is by looking at cluster outskirts on and how is the effect contributed from ICM versus the, the large scale filaments is that once you go outside of several times of areas even around the most
09:28:50 most massive clusters.
09:28:52 There are significant contributions from the large scale filaments. They actually tend to have these do tend to the six Kelvin gas, typically, and so I could easily imagine that if you have a galaxies that are embedded within the cosmic web, which actually
09:29:08 typically has the virile temperature, like the the cosmic web itself has zero temperature of 10s of six Kelvin, you might get quite a bit of contribution from large scale structure so when you actually start galaxies that are sitting inside of those filaments.
09:29:21 filaments. We have to be thinking carefully about whether you're getting contribution from CGM like the dark matter with individualized regional Halo versus the large scale structure shock.
09:29:30 So this is something that probably needs to be worked out on these physics I'm hoping cooperating in the hundred simulations and in principle once you do that exercise or pulling out What are you measuring CGM are you measuring IBM are you measuring mixture
09:29:42 of those two I think that changes a function radius away from the galactic center.
09:29:49 All right, near you have your hand up.
09:29:52 Thanks. Yeah, so this just I guess just to strengthen the points that Joe and dice get just just made that cosmological simulations even after high redshift above above three, we certainly see very hot guests and of the six Kelvin gas form and do do large
09:30:09 scale, Christian shocks in the cosmic web in people here in Fernie mentioned the intro pancake medium.
09:30:16 So at high redshift that that gets very hot Tim six covenant above in the cosmic filaments as well. So I think going to ask his point is well taken it'd be interesting to disentangle the kind of large temperatures due to a Christian shocks, and other
09:30:47 of the cosmic web versus the more spherical accretion shocks that we're used to thinking of.
09:30:43 All right, Mark, something that we have licensed to speculate.
09:30:49 One of the things it's on my mind is, is the difference between relativistic energy and energy density and non relativistic energy density. When you're kind of blowing out bubbles and they're expanding and rising, that the power law of your poly truck
09:31:07 matters as to how much energy density you then have far out. And so most cosmological simulations like us you know it's the whole kind of thermal energy, and not relativistic plasma.
09:31:22 But, does anybody have a feel for whether that is going to make a big difference.
09:31:33 I'll take that as a no.
09:31:36 But, yes, it is you included like a higher percentage of causing great energy, things might turn out differently.
09:31:47 So near or dicey Kate.
09:31:50 Do you have thoughts about why cosmological simulations might not be properly capturing they shock eating in these filaments, is this a resolution problem, is this a problem with modeling of seller feedback and low mass galaxies that are in those filaments
09:32:04 or what what is your thought.
09:32:08 I don't think it has anything to do with feedback because a lot of this hot gas exists really far away from any galaxies, this is really deep IgM.
09:32:18 The resolution issues and interesting question and something we're actively looking at right now by looking at a series of the simulations of the same volume run with different resolutions, I, I'm skeptical as to how much of the heating is a resolution
09:32:48 dependent of course. Subsequently, the cooling out of that hot medium is very resolution dependent and you can wind up with, you know, similar to as we see in this simulations of the circuit galactic medium, where as you increase the resolution you precipitate
09:32:54 out more cold gas. The since we seem to be seeing similar features in this intergalactic Shockey to gas but yeah that's more, more, to be seen, I guess,
09:33:03 maybe one question I have is that maybe more for the Nick and calling is his home, like when we actually do these stalking measurements out the very large Radia I wonder how much like projection effect large scale structure projection effect can contribute
09:33:19 to this is the effect as you go to larger radio, and whether we haven't accomplished enough large enough volume on that can, like, large scale filaments is kind of permeating throughout everywhere throughout the cosmic volume and have we consider all
09:33:32 of the projection effects so that's maybe one question that I have about the comparison. Is that Is there room for more projection of these large scale filament out to be on Giga parts equations, is that properly accounted for.
09:33:46 So far in the, in the, in the comparison at the moment.
09:33:51 I'm happy to say a few words but I know Ben has his hand up so not the order of operations. I think you should go ahead Colin leader.
09:33:59 Okay. Yeah, so we include the so called to Halo term right when we do it the forward model for these signals. So, at least in the context of the halo model picture of large scale structure, you know we are properly accounted for the projection effects
09:34:13 would arise. For plank for example this is very important because the resolution of plank isn't so good with act. It's less you know it's it's a smaller effect because the resolution is a lot better so you really are measuring the stuff associated with
09:34:24 the object of interest, but it is still important.
09:34:28 object of interest, but it is still important. I think the contribution from the filaments is a really interesting question there been some initial studies with plank data, trying to look at stacks, where you, you know look at the region between a pair of galaxies oriented in a proper
09:34:42 in a proper way. And people have looked and found initial sort of like few sigma detections I think of the as the signal from filaments. I think the interpretation is quite tough with blank because of the resolution.
09:34:51 I mean it is it's, you know, it's sort of 10 argument resolution in the company mind maps with actor we can get almost a factor 10 veteran resolution.
09:35:01 So I think it's going to be quite interesting actually to try similar exercises. Now that we have these wide area, multi frequency maps from act i think there's actually very interesting question try to pursue.
09:35:11 Yeah.
09:35:12 Miss Tasha asked a question, and I think it's directed toward you call it.
09:35:17 Does the Hilo model and to Halo term under predict power in power spectrum around Halo edges and could that be a similar issue.
09:35:26 Yeah, that's a good point. It's true that the region where the halo model is traditionally least accurate is in this transition regime between the one Halo tournament material the term.
09:35:36 Yeah, that's an excellent question. I think the you know the way to check these things is to do comparison to predictions from hydro simulations where everything is included by construction.
09:35:48 Yeah.
09:35:49 Yeah. Nick Price thoughts but this is yeah no no I agree with everything calling to said, as usual, and I'd like to point out remember these are see mass galaxies for the comparison and I'm a day oh so they aren't you know your run of the mill like smallish
09:36:05 Milky Way size, these are pretty massive generally the biggest things around.
09:36:10 And remember the thermal iz drops off like massive the five thirds. So in order to get sort of a significant contribution in the, in the outskirts or along your line of sight, you have to have like chance alignments with like clusters, or massive groups,
09:36:23 and that doesn't happen too often right in particular, these are often chosen to be isolated, at least for see mass. So, you know, there and, and as Colin said when we do the modeling, we do project everything out in the simulations out to very large
09:36:38 radio. So, if they are in the simulations, they will be there in our in our comparison.
09:36:44 So that's, that's one of the reasons why I'm not too concerned if we were to push down to say Rachel's question and try and do things around 10 to 11 solar masses, then yes we have to be extremely careful about projection of, you know, these line of sight
09:36:59 projection effects into Halo terms there, because those will be intersecting tons of at least for the thermal I see those would be intersecting tons of other halos along the line of sight.
09:37:09 So yeah, I would be, I'd be more worried there than I would be inserted these sort of group scale objects that we're looking at. Let's see maps for these very low mass things I think you need something more like CMVHD or Outlast to really try to attack
09:37:24 those, those questions.
09:37:26 Even with us something like CBS for.
09:37:30 I think the to Halo term is especially for thermal sZ it's just too big to say something precise but these really low mass object.
09:37:37 Can you can you remind me of the time scale of like last and these new yeah for LS that's good question. I know Sam PhD was going to propose as a.
09:37:47 Maybe sort of similar timescale to later timescale after CBS four so sometime in the 2030s.
09:37:54 I last might be sooner than that I'm not sure. So Claudia is on Claudia can tell us about is the API.
09:38:01 Yes.
09:38:02 So, the we, the design study will be concluded in the 2024, and the end of it we will have a budget, and we will also have the.
09:38:22 Let's say the study in place to marriage with the Japanese alecky Rajat.
09:38:30 And at that point, it will be you know the, we will start approaching funding agencies etc etc so I don't see construction happening, Donny maybe it is more optimistic but I honestly don't see this happening before.
09:38:53 2030.
09:38:53 So yeah, that's them.
09:38:58 But also there is also like in you know in Europe, unless we get someone from the US to help us with the funding in Europe with the options are limited, so we have, Of course we are looking at is some Max Planck, but so as a little burden to to take on
09:39:17 Max blank. But so as a little burden to take on their shoulder before they can find Atlas which is the ESP. So they basically you know the, these are the G told us very clearly like we first need to secure the funding for the ESP before, thinking about
09:39:50 expect to be sensitive enough to.
09:39:53 Now they predict certain numbers we have to wait until we have a telescope simulator because right now we are extrapolating also in terms of number of pixels we have, because we are aiming for two degrees field of view.
09:40:08 So, right now there's not the technology to feel it, but we hope to feel it at some point and that gives you a lot of if you manage the field entire field of human detectors that gives you a lot of senior.
09:40:21 Yeah, but they need us like is there is some preliminary numbers if you want.
09:40:25 In this peer paper or in the Astro 2020 papers, but the numbers will be more like liable after the design study.
09:40:38 Let's move you a little bit off bit but if while we're waiting for these, you know, new capabilities. There are going to be in the near term future although not immediately sort of next generation radio telescopes, you know, continue on an h1 and so in
09:40:54 week four we heard from Larry Flynt about, you know, looking at the, the lack of each one, and other signs of stripping and galaxies around the Milky Way.
09:41:06 There may be some potential for doing that. Around lower mass isolated galaxies, as we have lt ism as we have next generation h1 telescopes, I don't know about those capabilities off the top of my head so if someone else wants to say something and they
09:41:19 should go ahead but I think that lieu of direct measurements for, we may be working with indirect measurements for a while.
09:41:29 I think Mary is on the call, and she wants to say something about the future radio capabilities.
09:41:39 Okay, just and yeah the main surveys going on there's in South Africa, I know less about those and also the ones that in Australia, there's the Wallabies survey that's doing the entire southern sky, and I mean alfalfa kind of blew apart, what we knew
09:41:57 about the Tron mass function, etc. And the smaller one that small and the 33% of the sky that Arecibo covered and so as cap will be that much deeper I don't have the numbers right on my head but it'll be able to get a Leo t which is only about 10 to the
09:42:13 five solar masses of gas as probed by nuclear hydrogen which is going to be the main component, it's just going to take that that much further and I'm sorry I can't, can't spit out the exact number right now but but it is true in terms of probiotic content
09:42:29 below mass galaxies and gas content and also Halo features. It also has this exquisite resolution, combined with that so you'll be able to map a huge suite of galaxies, and so you'll be able to look at what's going on the disk Halo interface in terms
09:42:44 of that cool guests as well.
09:42:49 Great, so maybe we don't have to wait till 2036, after all.
09:42:54 Okay, so I'm going to switch gears to a comment by Ben, actually, who also had his hand up so maybe, maybe he'll.
09:43:02 Enjoy this but I at.
09:43:24 understand. And so maybe Ben wants to elaborate a little bit on this and perhaps some of our panelists can chime in as well.
09:43:33 Sure. Yeah, um, yeah I've been thinking a lot about groups lately, you know, I am in 200 and very old between kind of the 13 and 14 that intermediate range between clusters and an all star galaxies and, and something I you know it related to what we're
09:43:50 talking about earlier is how they are you know appear to be evacuated of a lot of their baryons, which you know is one of the strongest evidence of, you know, for, you know, pretty effective, you know, super one feedback, probably working at high redshift
09:44:10 so I have my hand up earlier saying that there's nothing to, you know, it should not be surprising that you know you can blow a lot of variants out at high redshift.
09:44:25 You know, hundreds of color parsecs which becomes, you know, make it you know make a parsecs or a makeup artist or mega parsecs later on, without needing to see like you know these fr to radio sources, maybe, those are working at high red shift in a way
09:44:41 that is surprising so pushing up you know these types of observations of of the where the barriers are what they're doing at high redshift.
09:44:52 I think is something a lot of us would be interested in, especially in terms of how groups appear today.
09:45:10 That's,
09:45:10 I think it's a great you know it's a great point groups are infinitely more easily observable, at least in some way advanced, you know, small cables and.
09:45:27 And with future capabilities, you can actually observe them it's very hard to shift, so you know for example for links we projected that we can do you know groups below 10 to the 14 and range of a few times 10 to 13 and treacherous of three.
09:45:39 You know, and not just detect you know it's collected enough signal to measure, you know, Thermal dynamical properties structures, and then brings those measurements in terms of mass scale, you know, relatively close to the scale of galaxy formation.
09:45:55 And in terms of cosmic Apple right and the apple, where you know the action is going.
09:46:00 So, you know, this measurements are very very important now and there will be, you know, very important than the future.
09:46:10 So sorry, I just said, we love groups, these are these are ideal objects for us with sZ work. I mean, this is essentially the scale that Nick show the measurements of already with act.
09:46:23 We're doing similar measurements with this project ID field k is the estimator in my group but five six sigma significance already with just pulling data.
09:46:38 Yeah, the forecast that we did for the you know the Simon's observatory and CBS for Astro 2020 reports indicate that we're expecting, see all the noise of probably hundreds on these types of measurements in the next five to 10 years so it's a, it's this
09:46:54 is a regime where we really expect transformative measurements to happen so I'm very happy to hear that people from the simulation theory side of things are interested in learning from these measurements because we're going to give you a lot of them.
09:47:05 Yeah, so I'm happy to hear this. Can you say like where you know what redshift specifically.
09:47:13 Yeah, we've, so we forecasted things out to redshift and one for sure, where I think we have a better idea of what the samples available for cross correlation are going to look like from Desi for example.
09:47:24 We also have these amazing catalogs from photo metrics surveys of course as well.
09:47:29 A lot of the forecasting Nick talked about is for spectroscopic surveys, which are a bit cleaner in some ways, but we have these infrared selected catalogues from wise that contain 500 million galaxies, sort of massive galaxies low mass groups and analysis
09:47:44 T is obviously going to be a machine for finding this stuff as well so I think we have a pretty clear picture of you know what we can expect to these measurements out the redshift one, they will certainly also be data into redshift have to, I just think
09:47:57 that we have less, maybe have an issue idea of how many objects to expect that then what their properties are going to look like if they're truly evacuated of gas, for example, then we won't detect as much signal because there will be less signal to detect
09:48:09 but that was still be a very interesting observation right.
09:48:14 If you try to look for gas and you find that there's no gas there that's already telling you something quite interesting, I think.
09:48:20 But you're sensitive to gas at large really more so. That's right. Yeah, that's right, gas that other others, you know, that is missing. In other probes.
09:48:31 Yeah that's right yeah so even with current measurements from blank for example we've now confirmed that you know the cosmic berry on abundance is present out at several times the radius average of the one for example.
09:48:44 So the missing parents problem in that sense kind of is solved in the sense that we know that they're out there they're just a large radius, and then the question is how they distributed as you go down to the smaller radio.
09:48:54 So we're definitely gonna learn a lot about this in the next five to 10 years.
09:48:59 Excellent, and one, one thing I'm interested in and maybe admin to I think you just have something to say flashes mute button or a roar I can comment on this, um, how much then in that case, do we stand to learn about kind of resolving, some of the arguments
09:49:17 about the Milky Way Halo versus local group, medium,
09:49:26 It's not just two out of left field. If you don't want to talk about that and then you can say what you're going to say otherwise.
09:49:41 I guess I'd have to think about that a little bit more. But what I was going to say was related to that which is I think it would be a good idea for
09:49:45 people to think about like how to combine the metrics that we're going to get out of a survey like Argus with what we're going to get out of this the is you're going to get complimentary information and something similar, like that could be done with
09:49:59 the Milky Way. Some already because we do have better absorption data for our own galaxy.
09:50:07 In terms of resolving whether or not. So, we discussed back and we for the way Andromeda have not yet had their collision which means that that whatever group medium is there is not like what it would be if you had a possible group with, with a galaxy
09:50:26 that emerged and then now, it has its surroundings and the total mass of between the two of them is not all that large, so you wouldn't expect to the temperature, especially high so I think that maybe some of the like the work that she was doing on like
09:50:43 the local bridge. I mean, understanding the, the, using sZ and and other metrics to understand the current dynamics between the two is going to be pretty interesting for how we interpret data from other galaxies, whether or not we can really isolate something
09:50:57 that is clearly a local group versus something that is, you know, title, related to the the two yet to merge big galaxies.
09:51:07 I'm guessing that we will not be able to completely, say for sure that there is this, this more diffuse extended medium lives, absolutely unreal, that was like a precursor to what's already there.
09:51:24 All right.
09:51:26 So, thank you, admin for clarifying that. Okay, so I'm, I'm going to switch now to a comment by Brian O'Shea.
09:51:36 And if he wants to unmute and speak for himself he's welcome to do that as well but he he's hoping that with CGM dynamics.
09:51:47 You could make stacks of galaxies based on orientation, including tilt with respect to the plane of observation, and you could then principal say things about outflows inflows in addition to rotation and and so this does sound absolutely tantalizing to
09:52:05 me and Nicholas Battaglia seems to agree so maybe I can get people to talk a little bit more about the dynamics of the CGM.
09:52:22 See Brian you're unmuted but we can't hear if you're talking.
09:52:27 Sorry I'm having your rotating computer problems. Well you you covered my question in the answer so I think we're good from my end I am curious to hear what other people have to say about it though.
09:52:40 I just wanted to come in so I think we haven't, at least I may have missed it. If it was earlier but I don't think we talked about the rotational kz effect in too much detail but if you have galaxies that are rotating differentially as we sort of expect
09:52:56 to be the case for many objects. You can, you know, build estimators to look for this effect.
09:53:00 For example, if you have some a few data that gives you some map of the velocity structure of the object, then you can do a stack.
09:53:15 There have been attempts to look for this so far and data from. I think just plank. And we just have upper limits, but we do expect to be able to make the actions of this single the next, I'd say few years, and that then tells you about how the gas is
09:53:23 is actually rotating within the halo which is, which is pretty cool. I think people haven't maybe thought too much about what we can do with that signal.
09:53:33 So that could be an interesting thing for people to think about here.
09:53:37 Yeah, so that was, that was the final bullet. That's what I was referring to in the final bullet of my, my presentation. But I think what Brian's asking is, in principle, if we have, you know, there's also potential you know the Galactic fountain right
09:53:50 so it would depend on how far out this this Downton went are these outflows went, in principle, if that was along the line of sight. This is, and we were had we had some tracer in which we could use to orient it.
09:54:04 We could try and look for that as well as, as opposed to the rotation and what's kind of nice is if you pick something that you think should correlate everything else, like the rotation or even the pure velocity should cancel out, it'll just be additional
09:54:17 noise to what you're trying to actually observe. So, if there are ways and people have shown that you know this particular estimator aligns with, you know, your outflows, then that is something you know the KFC is sensitive to is the are sort of line
09:54:33 velocity. So, in principle, it could work in practice, it's probably the devils in the details right but I think we just need this, this tracer right I don't know if you have ideas for what this would be that if there's some observational tree so that
09:54:51 we can have of these potential outflows by, this was a great idea. Yeah.
09:54:57 I think if you have a if you can take like an optical survey and basically estimate which way the galaxies tilted right i mean if you have a spiral galaxy you know this galaxy, you can.
09:55:09 It's disc shaped right so if you are looking for something that's tilted along the line of sight, you can basically look at the, you know, electricity of it, and make a very coarse estimate.
09:55:24 And I know.
09:55:26 Stephanie whoa is here and I know she's thought a lot about you know galaxy orientation effects from an observer perspective and simulation perspective.
09:55:36 So I don't know Stephanie wants to say anything not to not to put her on the spot and I don't know she's in a place where she can say anything.
09:55:44 Oh, I guess I'm just not too familiar to see in fact so I'm not sure like how, like, at least from my knowledge, how to connect that Mass Effect to like my like up magnesium to observation for the coal, gas, but like having combining geometry you have
09:56:10 detected with like another bed, we finished up for useful as like in Christos talk. She also mentioned like how important is geometry and like understanding. For example like outflow inflows so you guys just talked about.
09:56:17 Yeah, I mean I I know that I'm very excited by the prospects of this for sure. Okay, so maybe in our last four minutes I can get some of the panelists or keynote speakers to just talk about ways in which the sZ community and the X ray community can interact
09:56:33 productively to kind of, you know, get a handle on some of these constraints that we're talking about.
09:56:49 So here's a related thought that was going through my head. And to answer this question of whether this sort of excess energy or pressures is coming from the inside and sort of being pushed out from the cluster, or whether it's sort of accreting, or you
09:57:00 know, coming from filaments or the cosmic web. It seems like combining X ray observations which mostly probe the central part of the object with these more extended see observations should be a really strong constraint on that problem.
09:57:16 So of course you can look in simulations but simulations are expensive. So, you know, I know that this group has been developing this parametric model.
09:57:26 And it seems like that might be a really powerful tool to try to combine these two kinds of observations together and and answer that question so that's one way, maybe that the two communities can interact is by, you know, by a model which of course helps
09:57:40 us to to tie those two physical processes and tie them together.
09:57:47 Yeah, I think it's fundamental to realize just how complimentary, you know as an X ray observation saw x rays fundamentally can image individual objects results structures inside the video radios.
09:58:01 As the You Can you have a capability to do huge samples trace the gas you know very far out.
09:58:11 These are just different, different types of observations that, you know, we will do eventually. And, and it is, it is important to be able to do huge samples entities important to see what's actually going on.
09:58:25 This is a lesson we you know we learn from doing galaxy clusters when we, you know, back in the day when we modeled extra symmetrical surface brightness profile we're not learning much it's when you know gender came online and xmm and we started really
09:58:41 emerging, you know, to these 3d structures, that's when you know the, there was an evolution and understanding your customers.
09:58:52 Kill I notice you have your hand up maybe you have some thoughts on this too.
09:59:00 So, you know, one can take a look at what might be coming down the road by seeing what has been done clusters just amplify them and the Lexi said there were big efforts that were very successful comparing X ray mission, SC week lensing.
09:59:19 The Maven one or two other things together, to understand what the differences were.
09:59:25 They weren't that great so you know we know things like gas and clusters isn't highly clump and giving us misleading information.
09:59:38 And
09:59:39 one can try to do this with, you know, various stacks of nearby objects and I say nearby because if you're going to get x ray emission.
09:59:51 You have a big advantage of using objects and 0.01 instead of one.
10:00:02 But you know that's that's certainly possible. And it's, I think we've done just as much as we can with current instrumentation. But coming down the line with Athena, and in a mission with Athena and Hobbes, the Chinese project will give us love information
10:00:27 on the extent. Right now you can take massive nearby spirals for example.
10:00:37 And you can see their X ray mission you can extrapolate them out to our 200 and compare them to what you expect to see with.
10:00:48 You know what seen an SC stacks, and right now there's a very significant discrepancy.
10:00:54 Because I think the SEC stocks are mainly weighted toward early type galaxies live in clusters and are often contaminated by that sort of signal.
10:01:07 So I think the future is, you know, pretty good. And we can see that from what we did and what was done in clusters.
10:01:17 Great. I like ending on that note, the future is pretty good.
10:01:23 Alright, it's 10 it's one after the hour here.
10:01:28 I'm just want to thank our keynote speakers again and all of our panelists for a stimulating, I think productive discussion and a very forward looking, we have tomorrow, where will come back and do some of the structure discussion work do deep dives into
10:01:45 into some of these really interesting questions that have come up, so I'm really looking forward to seeing everybody back here tomorrow. In the meantime, I'm going to post that new workshop photo with our additional I think something like 45, people that
10:01:59 made it into the photo. And don't forget the social event today at 430 on room and GG room it's going to be so cool. Bring a drink and. Thanks so much everybody.
10:02:12 And we'll see you tomorrow. Thanks, everybody.
10:02:17 Thank you.