09:06:29 Okay, so, time for the panel discussion on our panel just to remind you, these people have panel privilege, meaning they don't have to raise their hand to speak they're encouraged
09:06:48 to chime in. And this. Our speaker of course Chris Martin. I took style, Joe Burton crystal Martin and Sarah Tuttle. So, we will defer to our panel members in, in all of the comments and questions.
09:07:07 If you have something to add to a discussion that's happening right now. go ahead and raise your hand. Otherwise I'm going to you know be looking on the slack where I am very pleased to see people have been using many emoji so I'm going to start first
09:07:22 with a question from Todd and then within a denim from Rahman immediately under, under neath and Todd says he's all in on Halo.
09:07:33 And he says, you know, if we could go even deeper that would open up exciting up diagnostics. And the question, ultimately is kind of getting at what are the opportunities right like the levels of funding for the different kinds of missions.
09:08:08 what's a probe versus, you know, a pioneer, as many of us don't know so what are the opportunities, and what are the kind of timescales involved, and most importantly, from wrong mon, how do we get involved as a community to help get these missions funded.
09:08:05 And so I'm going to open up the floor first to the panelists who might want to comment on these kinds of questions.
09:08:14 I can comment said okay.
09:08:19 So in terms of funding levels.
09:08:23 There's an inverse correlation between funding, and I know there's a correlation between funding and timescale okay so hopefully it's not linear.
09:08:34 There is, there's the suborbital program that's our balloon program but that's a one night.
09:08:43 Camp campaign.
09:09:00 And that's more like 20 I guess now.
09:09:03 20 million.
09:09:04 Something like that I mean I think that the, the advantage so, so I would argue that the the part of what you're asking here Todd isn't just funding but also access and I think one of the challenges that we've run into, especially for this kind of it
09:09:32 like observing the CGM or the m&m mission. One of the big challenges is that we know it's faint we know it's diffuse. And because we're always running up against this environment where it's about, you know, bang for buck. I think that it is always challenging to suggest, like, let's do something where we sit and
09:09:45 Right, like we know you're also like we all also check into, like, has anyone thought about exoplanet atmospheres as these like you know you just, there's all these other things right.
09:09:54 But I think that one of the challenges is this is an important thing and at several skills and at many wavelengths and redshift, we should do some sitting and staring and in a bunch of space.
09:10:04 And so, you know that you get a with different money you get different things right so as Chris was mentioning, for less money you get either smaller telescopes, or less days, or both, or last time.
09:10:16 Right. But the more money you ask for maybe you get a bigger telescope or a longer mission. And also, you'd likely need to sort of, it needs more applicability.
09:10:26 So I think that's, you know, the sliding scale I will say that in the not too distant past, Thomas a virgin complained that astrophysics doesn't fly enough.
09:10:37 We have a somewhat different model and it is challenging right because we do have these things where we're like, well, it's hard, but also we're not looking for super bright things.
09:10:46 And this this has been some of the balance between say, being able to do things and absorption, you know, maybe you don't know the lions running at you but you have a flash that tells you there might be a lion.
09:10:56 You know, but we can do it a lot faster. And so I think that's where we're at. It feels like we're on this precipice where we might finally have enough, enough people convince to spend the time and the money to just like hanging out in the bush and wait
09:11:10 for the line.
09:11:12 But, Chris has been playing this game a lot longer than I have. So I don't know if it feels different or if it just feels different for me.
09:11:18 I love that sounds like okay so Chris go ahead and then I'm going to ask Todd to heat sounds like he wants to add something to.
09:11:25 Oh, I was just gonna say first of all I think the Explorer program is probably the best way to get these on because it is a regular program and it's a popular program but I think I agree with Sarah that right now they they fund more or less the same number
09:11:42 of heliospheric and astrophysics missions, but the astrophysics missions that you can do that there's so broad and wide ranging and impactful, that we should really be double what it is now.
09:11:55 And, you know, that's obviously the function of the detailed survey and the last survey did make that point.
09:12:02 And that basically prevented it from being cut.
09:12:06 But they said double it. And I think, I think we should continue the pressure so if you're on an astrophysics panel. You know that subcommittee whatever you need to continue the pressure to increase the Explorer program, and then above that, you know,
09:12:21 it's really hard but you know if the cable decides there's a probe program that would be a billion dollar level.
09:12:28 And you can do a huge amount with the probe.
09:12:33 So, so, oh thank you can hear me okay yep so I have a kind of a historical reflection.
09:12:42 So you can hear me okay yep so I have a kind of a historical reflection. But the real point is that there's a value in combining marketing with kind of flexible design. So, the historical comment is that the fuse ultraviolet telescope.
09:12:56 Everyone here probably thinks well that was all about oxygen six, you know, oxygen six was the big killer app, but it wasn't oxygen six was a kind of us pretty secondary thing for the fuse team.
09:13:09 The killer app was deuterium, which in those days was a big FM deal and so that's how they sold it, but this connects to Sarah's comment, because once fuse was up there.
09:13:23 Then they decided okay well, why don't we stare and, and why don't we sit and stare some more and now let's tear some more than that enabled fuse to do stuff that was totally unexpected.
09:13:36 For example, fuse got a resolve recording of the helium to live in alpha forest it wasn't you know just to try off it was actual, you know, a real lyman alpha forest except in helium to and that was possible because they did what Sarah wants to do you
09:13:52 stare at a new car a new car so more. So, you know, that the thing is is you, you do have to have a killer app that gets the game started but then beyond that, if, if the thing is designed with a lot of capability who knows what it might do, and and so
09:14:10 that's, you know what, I hope, might be possible with one of these promptings, and just the other kind of question related to funding in my mind.
09:14:20 The ideal thing would be to fly simultaneously something X ray capable like arcas with something that has ultraviolet capability, probably not the same telescopes, of course, but in the sky at the same time.
09:14:36 So a question is could could we afford that could we. Is there some way that we could have that X ray spectroscopic capability, and the ultraviolet at the same time because they really complement each other.
09:14:52 And so, so that's kind of related question.
09:14:52 And as anybody from arc is here because I actually think that that's a really good point, and at the same time, you risk getting the kind of feedback from NASA where it's like, well artists has already doing all of that science you want to do with your
09:15:05 up right like from your science traceability matrix. So why do we need the UV if we've got artists right so like, how do we how do we as a community come together to convince people that both are actually incredibly valuable and sounds like Randall Smith
09:15:20 wants to say something.
09:15:24 Well, yes sir. Since you asked if somebody for Christmas here on the poi, and completely agree that the.
09:15:35 We need both.
09:15:38 And it's even been discussed could we put a UV telescope on artists. And the sad news is basically for $290 million. The answer is no, you simply can't do it, but I think Todd's point that we just need to double the four program and it really was in the
09:15:55 last decade old a request to increase it, and that didn't quite happen.
09:16:01 But you know there's there's no way around it, you do really want a UV, you know, soft X ray absorption and UV emission, and ideally spectroscopy as well.
09:16:11 There was even a proposal back in 220 years ago.
09:16:17 20 years ago I believe between Hopkins and Wisconsin, Todd probably remembers it that had both of them in a mid x, but basically it was never quite, quite doable.
09:16:32 in the kind of budget, you have. So, by completely agree the main headquarters does listen to the community. And if they hear it I'm loud and clear, that, you know, this is what we need and we need to do it.
09:16:43 We can do it with with explorers, which is, you know, there are certain things we can still do with explores, and some things we need probes and something that we need flagships for but this is an area where we can make real progress with explorers and
09:16:56 I think we should be shouting from the rooftops.
09:17:00 I mean, what one thing to put out there for sure and, and over the few years I was on the CO packing you see this was a conversation that was getting, you know a lot of support and framing is really thinking, even if the Explorer level of framing things
09:17:13 in the great observatories mindset, but more explicitly really thinking about multi wavelength approaches for all of these problems that were historically and I, of course, nobody in this room but historically it's very easy to get kind of siloed into
09:17:27 our band passive preference, personally, you know, because it's challenging you know the technology's changed pretty drastically it's a we shift from the UV through the X ray and, you know, all through the optical the infrared you don't often see the
09:17:44 same thing in house in one place, but clearly the answer at this point is a single band pass is not answering these deep astrophysical questions right and so figuring out ways to kind of present things increasingly in that framework and I think there's
09:17:56 always a tension as a proposal writer and as teams, because everyone is aware of limited resources in the room right so as Todd says you would like to be the killer app, you would like to present your thing as the thing that's going to practice the answer
09:18:10 and figure out ways that we can sort of build those alliances and share those with NASA I think it's really important.
09:18:16 Yeah, I was going to ask what those alliances may be. I mean, given that with increased funding required that necessarily increases the breadth of the science that is likely to be done with with these instruments and facilities.
09:18:33 So, you know, I mean, In, in sort of the conception of Halo was, was this is this in the, in the mindset of the team. In other words like is the killer app, what we all really are kind of pushing for and hoping for, in our own scientific preferences in
09:18:54 this group, or, or is there, wider, buy in from the rest of the community.
09:19:03 Maybe I can take a crack at that i.
09:19:07 So, the answer is. Everyone says you have to have a killer app, and that that's the way these proposals get evaluated there. It's almost as if you have to have a deterministic path to a scientific breakthrough which is obviously challenging.
09:19:23 So, you cannot propose a capability.
09:19:30 Even though, in the end, when it goes up. That's what you really want a capability, and you, you will be able to do the science you propose but you also hopefully be able to do a whole variety of science.
09:19:39 And, you know, we don't have a UV interval field spectrograph in the sky. And you can imagine a huge number of things you would want to do with that kind of instrument.
09:19:53 And, and so you could write a very gentle proposal that touched a lot of basis.
09:19:58 And, and it's finding the balance between that and bringing in a larger community and doing something that's focused and will debt demonstrably yield a result is, is the big challenge.
09:20:12 I have from working on a few proposals in recent years I've always thought the scientific trace of the science traceability matrix is like fundamentally like squeezing your science in a way that's like unscientific it annoys me like can we change it.
09:20:30 This has been a trip, that has continued, it's gotten worse and worse and because we, because we all kind of bite into it.
09:20:38 And we need to have a revolution and say we want to build a capability and here's what we think it might do and it might do something even more exciting, so you know I don't know how to do that but i think i think there needs to be some sort of disruption.
09:20:57 I will say I think that there are certainly opportunities for different approaches right so one thing that we don't do a great job with or that is just really different that I somewhat recently learned about like in planetary science.
09:21:14 For example, the way that they sort of stage their funding and there they have Picasa which is a whole program, where I don't want to say can propose things that are on the back of an envelope, but the idea is that, you know, even pretty wild ideas that
09:21:27 that are much less say well grounded in the science traceability matrix.
09:21:31 Absolutely would be welcome and are funded and. And at some point, you know there is there is, you do require some justification of like, we picked the pieces in our satellite for these reasons, not just because they were convenient or someone was sell
09:21:46 them to me or the whole total was under $5 million, or whatever, right so I feel like there isn't in between there needs to be some connection between what you're doing and how you're building it, and I 100% will put instrument builders on the table here
09:22:00 and say, yeah, if you let us just like build cool stuff will do that and probably need science will fall out.
09:22:06 But probably we should have some constraints there or not, I mean go wild, give us money it's fine.
09:22:13 You know, but I think the fact that we don't have a ton of kind of blue sky room that we are kind of stuck in this place of like what are the three parameters, you're going to measure and you promise to guarantee you know i think that that can be very
09:22:24 constraining.
09:22:26 Yeah.
09:22:27 Okay.
09:22:29 Can I chime in on this briefly. Sorry, so this is Chuck.
09:22:33 I.
09:22:34 It seems like the elephant in the room is really for UV at least not so much X ray is the success of instruments like Casey wi and us, where it's much cheaper.
09:22:48 If you want the UV to go to a little bit higher redshift than it is to put something in space, and that is the whole thing that's working against you, capturing the interest of a wide variety of people because you could do.
09:23:02 Many of the things. There are so many things that we could do from the ground for a 10th of the price.
09:23:23 Yeah and and I agree, and in fact, when I first started talking about Halo. That was the number one question that people JPL would say, Why can't you do this I read Jeff and that's why through that slide about the difference between the hybrid shift and
09:23:26 low Richard universe, I think
09:23:27 we, you know, just this the quantity of data we have in objects in the lower edge of the universe and the opportunity to to really determine what's happening physically is so much greater.
09:23:39 As much as I love the Hi, Richard universe and but but more importantly it's, it's an opportunity to do this experiment we're comparing properties at high and low redshift, it's it's a secondary argument I agree Chuck, and that's that's the problem making
09:23:53 that argument we need to we need to sharpen our, our talking points, I guess.
09:24:01 I mean, I guess I'd also push back a little bit check both against the order of 10 because I think that that's a little high, but also sort of the imagining that on the ground there is money sloshing around to build a set of instruments right I think
09:24:14 we're facing. Quite an aggressive punch, punch in terms of ground based instrument funding, at least in the United States hats off to Europe for having their shit together, but not here so much as i actually there's a much larger conversation about what
09:24:32 we're doing on the ground that that is open there. But I think it's a little less obvious but that that's sort of like an easy Georgia walk through. I also will you know fight to the death for observing local things I think it's important for the physics,
09:24:42 as well as, you know, I was just trying to be the devil's at the devil's advocate, and and somebody who doesn't work on up stuff in space but I consider myself to be a UV astronomer, we still love I'm an alpha halos.
09:25:14 Oh, I mean I, it's just it's it's a hard sell because it's a specialized audience that you're always going to be talking to, in order to get the UV capabilities and low redshift.
09:25:13 I think Chris makes the argument actually I think a bunch of people in this room make the argument that understanding galaxy evolution and the connection between galaxy formation and evolution and cosmology is not a specialized audience at all, and much
09:25:26 love to our exoplanet and astrobiology colleagues, and they care you know eventually but not so much, but it's a big community. Right, I do think there's an, there's a quite robust argument that we are really talking about what is likely to be the crux
09:25:39 of how galaxies evolve.
09:25:42 And so that seems like almost everybody should care. I mean, obviously, So, okay so Todd, hold, hold your question or maybe type it on the slack I want to switch gears a little bit here, because I think that this is an incredibly interesting and important
09:25:57 conversation to be having. I also want to talk a little bit about some of the science.
09:26:04 Done. in his talk and some of the questions that I've seen on the slack that have been getting some strong reactions and in particular, I think they're related but like, One of the things.
09:26:17 Okay, so I'm just going to read a couple of kind of science questions and these are based on emission diagnostics, okay and I know that we have a number of panelists here who have done this, it in magnesium to emission climate alpha mission.
09:26:30 So first is the linemen alpha admission spectral information.
09:26:34 So when we go to and Dylan Nelson mentioned this so are the simple toy models able to reproduce the line structures. The red to blue peak ratios and of course i think that that opens this can of worms that Chris was talking about which is degeneracy is
09:26:49 and interpretation of alignment alpha profiles and then Cameron asks about possibilities from picking up oh six or nitrogen five with Casey wi in a mission.
09:27:00 What have we learned from say magnesium to and emission from KC wi. So let's just talk about some of the exciting possibilities with the mission in the new I of us that aren't on these 10 meter class telescopes.
09:27:21 I'm happy to say something.
09:27:24 I mean, I think, I think there's a bottleneck. Right now, caused by the absence of spatially resolved ways of modeling, what you're looking at.
09:27:37 And, you know, it's trivial to do optically thin emission.
09:27:53 If you've actually resolved the structure giving rise to the emission which is kind of doubtful. So far, But, you know, having, it's basically you have a map of the kinematics, and the spatial distribution.
09:28:02 And, you know, I think there are a lot fewer degeneracy is when you use all the information but there are very few ways.
09:28:10 There have been almost zero attempts to do for modeling of specialty resolved anything.
09:28:18 And I think that this is a huge growth area, it should be.
09:28:26 And I think we've been playing with various simple models ourselves that which are quite successful these clumpy outflow models that max crunk has has advocated and we've been trying to implement spatially resolve versions.
09:28:46 This is a student she really at Caltech, we spent working with Max and with me I'm trying to do this it's it's a remarkable how much, in principle, you could learn about gas flows, just from looking at the kinematics versus spatial position of even lyman
09:29:05 alpha, which is the seriously.
09:29:10 Hard to interpret. But actually, it's kind of obvious what's going on when you have a full cube and you see that every, like if every galaxy has various similarities that show that say that there's something common going on here.
09:29:27 That said, there's something common going on here. And I'm always fascinated by papers that say we don't understand lyman alpha emission from halos. Well, okay, so people are going to argue about whether 10% comes from, you know, gravitational cooling
09:29:46 and, but but it's kind of obvious what's going on when you look at a typical star for me. Galaxy in alignment alpha. And I think so. Generally it supports the picture that you get from down the barrel spectra and lines of sight to background sources.
09:30:06 Anyway, I've said enough, I think, I think the modeling is, is the key they're getting better tools for interpreting the data.
09:30:19 Great. And yeah, shout out to really Lee, who has a new results video on this, this topic, so it'd be nice if people wanted to check that out.
09:30:31 Joe, or crystal Do you guys want to say anything about your.
09:30:36 Yeah. Um, I think this picture Chris kind of showed where you, you take a numerical simulation right and you make a data cube from it, and then you really have a product that you can directly compare to this new era of integral field specs spectroscopy
09:30:55 data is really where we need to be headed. But I think it's going to be really challenging for the simulations right i mean we know that a mission is something that depends on density squared.
09:31:07 And we've been talking about the sizes and densities of the little clumps out there for eight weeks now.
09:31:15 And I'm really curious, I mean I think this is going to be a great area of growth over the next four or five years.
09:31:22 But I'm wondering you know if at this point, are there predictions for the emission, either in terms of its intensity or kinematics that simulations can make.
09:31:37 And predictions that are you know falsifiable, do we actually have the power at this point to rule out any in any simulation that you know has or doesn't have particular physics, because we're confident of the predictions that makes for remission and
09:31:57 if not right that that's a real challenge to get to and I think we should figure out, you know where the easiest place is to make a robust comparison kind of kind of what scale what redshift what type of object.
09:32:09 So I see that as our challenge.
09:32:12 And actually I noticed camera.
09:32:14 Oh, go ahead Joe and then yeah if I could just show something really quick. This is some of that exact kind of thing you're talking about crystal. We did for for the Phobos instrument.
09:32:27 Hopefully you can see a slide there was some simulation data and such.
09:32:31 Yeah, so, so, Phobos is a specter spectrograph concept for CAC 1800 five or spectrograph operating in a number of modes, it's consistent three specter graphs, which can be fed by.
09:32:49 Here we go, and sort of three modes, 1800 individual fibers, we can use one of the spectrum graphs to deploy these 60 fiber, sort of mini if you bundles, or we could just do only these if you bundles and so you can kind of get an idea of simultaneously
09:33:06 what you could do observation wise over here in this table, and just some of the just some of the other details of this is over a 20 minute field of view resolving power about 3500 and going down to about 3100 extra rooms, which is part of the real beauty
09:33:28 of this instrument concept. And so one of the key science programs that we actually want to do is to use these little mini if you bundles in some deep drilling fields, over a large sample of galaxies that about a redshift to in order to map in a mission.
09:33:48 Carbon for an oxygen six around, you know, a sample of galaxies that that really spans the stellar mass star formation space. And so this is some predictions from from foggy, where you have the density map the temperature map and then this is the footprint
09:34:07 of one of these little if you bundles.
09:34:10 And then this is the predicted velocity field foggy. How did you how did you get that predicted, uh, you know, map there what what kind of software did you use for that.
09:34:23 This is all thanks to Lauren Corliss and her machinery that she's developed cloudy based basically, yes. Yeah. Yeah. Um, so this is an example of this is obviously for just one galaxy.
09:34:37 And here is this galaxy in this plane so it's it's fairly low mass and fairly low stuff morning so we in 100 our observation, those data seem to predict that we would detect something, it's you know it's it's still tough.
09:34:55 But, you know, 100 hours, and you can get a signal.
09:34:59 This is of course expected to be the signal should be stronger for more vigorously star forming galaxies, more massive galaxy so I think doing these kinds of predictions over, you know, a wide range of parameters space in terms of the galaxies.
09:35:14 You know, could hopefully be brought to bear directly on these future observations.
09:35:18 I mean this is wonderful. This is what we want to be doing and Bobby's one of the better simulations for this at least in their papers I've seen them discussed quite a bit, whether things are resolved.
09:35:30 But here again you know that that that's the question I'm asking how much can that numerical prediction be trusted right what is the error bar on it, and I mean I know in foggy simulations as they increase resolution.
09:35:46 There's not a huge change but inflows and things they can tend to penetrate further and go deeper into galaxies.
09:35:55 It's hard to ask the question. Oh would you get the same thing if your resolution was 50 times higher. But you can ask the other question, if your resolution was 10 times worse, would you get the same result.
09:36:07 And that's what I'm not seeing.
09:36:10 I wonder I feel like something like a trident, but for if you modeling would be something that would obviously be very useful. Sorry, we have a package coming
09:36:22 be something that would be very useful. I don't know if Cameron can comment on on kind of the capability of generating that level of software and the difficulties inherent and you know the modeling.
09:36:34 Yeah, sure. So, actually, much of the work that Lauren Corliss has done is based on kind of the tools that we use to generate Trident some tools that Britain Smith wrote, maybe a decade ago for doing these massive systematic writing of cloudy.
09:36:54 For to calculate different ionization states of the gas as well as the emission components.
09:37:02 So, it is, it's been on my list for like four years to do this for if you data for Trident, but perhaps this is the kick in the butt that I needed to actually make this happen, because yeah for the most part the tools are there.
09:37:17 I think one of the main concerns is as as has been voiced by Chuck and crystal is, how do we adequately compare a simulation of instead of just saying like, Oh hey look, we have if you data that synthetic data and we have if you data that's observational
09:37:34 data, they look the same, you know, coming up with a real good way of comparing those data sets to see if there's agreement or disagreement because now I mean it's one thing to say the spectra that we have look like the spectrum, you know they have similar
09:37:48 line profiles and that sort of thing but coming up with similar comparison methods between a three dimensional data set, where, where there might be some discrepancies but how well do they align in terms of their phenomenal logical behavior.
09:38:05 I think that's, that's a potentially a larger challenge than just producing the synthetic if you data.
09:38:11 All right, I see you on raised her hand and sounds like she has something to say, Oh, yeah, so it would be great to be able to generate this synthetic data from simulations.
09:38:23 And I don't know, maybe I see more difficulties so Cameron, but I think it's probably actually really hard because you have to model the radiation, and you have to figure out what's ionizing all the gas that part I think is really really hard, um, I do
09:38:40 think it might be.
09:39:02 So, like, like the stuff that Joe show and Cameron side on many of us have done here we all know it's done and I've done it. We can use quality tables to generate some simple maps for, for example for each alpha.
09:39:00 And I think it might be easier to compare to kinematics. So, without properly modeling what's ionizing does stuff on the kinematics might be more robust and to some extent account while simulation was trying to compare the kinematics of the child of condiments
09:39:20 and clusters.
09:39:22 You know, the biggest galaxies CGM right
09:39:28 was with the observations that I did. So looking at correlation functions basically of the kinematics of imaging guess.
09:39:38 That's a great point.
09:39:39 Thank you. Alright, Dylan has his hand up to you. It sounds like he wants to say something.
09:39:43 Yeah, I just wanted to thank crystal for bringing up this point in some sense because I agree, and I think I'm comparing so for modeling from a simulation perspective into the observable have a nephew cube for mission is definitely a future and it's what
09:40:00 we're doing already, and some sense and I yeah so Chris flash these results from the Krispy rolls paper on the lineman alpha mission, right from the to do simulations, that is what his method does, so its tracks, every single alignment alpha photon from
09:40:17 a mission through the full scattering process as would be captured into an eye view data cube.
09:40:24 And our very first, I mean all we did in that paper was a first comparison to the Muse you def results in terms of profiles. So, we are beyond already looking at images and saying they look okay we're comparing the median stack statistical profile of
09:40:40 Lyman office surface brightness, or galaxies as a function of stellar mass, because that is actually the data already coming from the Muse Deep Field surveys so that's super cool.
09:40:49 And I think that same data exists right it's being looked at for magnesium to an iron to.
09:40:55 So I think all three of these lines which are all tracing kind of similar phases maybe and minis and to also as complicated as I'm an alpha, in some sense, since it's also resonant but these have anything amazing constraining power on the simulations
09:41:09 and I think we just need to dig a bit further and we will see that already the expectations from the simulations don't line up, and a number of interesting ways with the data, so I'm sure that we're already there, we already have the power to rule out
09:41:24 Siri, which is of course all we can ever do with data right we can do to complete for modeling the best way we can and does disprove a model, as it exists.
09:41:33 So I think we should just keep pushing on this and I think that personally if I'm an alpha and magnesium too.
09:41:44 In terms of the colder gas, we have tons of data and tons, tons of upcoming data and we have the ability to do to for modeling from the simulations to an extraordinary precision.
09:41:49 The question is, of course, are the simulations realistic converged correct, and any of these things and I think we can argue about that but that's what we want to figure out by doing the comparison.
09:42:00 So yeah, I think it's very interesting and timely.
09:42:04 Yeah, I just asked quickly kind of what mass, what what stellar mass range, and what redshift range. Would you like just offhand kind of like trust doing this I mean obviously in little dwarf galaxies, you probably don't have the resolution.
09:42:18 So, so what's the ballpark range where do you think this can work with present.
09:42:27 Wow. So for the Muse comparison. This was Richard three to five, and the bulk of their sources right for the linemen alpha halos on low mass. So I would say tend to the seventh to 10th in mind, still a mess.
09:42:39 So these are the resolutions where we have objects in the simulation but as you point out there at the edge of what we're resolving so they're certainly not well resolved.
09:42:48 But I think quoting this in terms of a galaxy man's is a dancing around a true issue right the true issue, as you also brought up is is is the components of the cold gas right which we know is extremely important for the lemon alpha.
09:43:01 So, if structure on smaller scales very small scales, you know anything less than 100 parsecs or 10 parsecs is key. Then, this is more important than quoting the galaxies which exists in the simulations because very few simulations are getting into those
09:43:17 kinds of skills, yet.
09:43:20 All right, go ahead. I won't, I won't skip over you this time, but I'm going to make a different comment than the one I had before, which connects to crystals question.
09:43:30 And this is kind of an awful thing, but there is a Boogeyman that I think it's sort of time to come to grips with which is that cloudy might not be right.
09:43:44 If this stuff we're interested in carbon for oxygen six stuff like that arises and turbulent mixing layers.
09:43:52 Well that's probably a time dependent non equilibrium situation and you know so I raised this point in my talk and I asked Drummond about it and he said yeah, it seems seems possible so it's sort of a challenge for theorists.
09:44:07 Is it time to look at that, that nasty micro physics and and come to a on at least some kind of understanding about whether what we get from cloudy which is sort of the engine of all these different things, is really reliable and actually probably depends
09:44:26 on context I would guess so maybe it works fine. I'm sure it works fine in some situations but there might be contexts where that the column densities the emission intensities and stuff.
09:44:39 Building on cloud er not actually entirely correct because the physics is more complicated than plain old ionization equilibrium.
09:44:51 I was just gonna make a comment on that.
09:44:53 I agree with you.
09:44:57 In the, the first approximation I think almost certainly you have to use cloudy as a grid model rather than a, you know, global model because you're going to have a distribution and the distribution, we really don't know what it's going to be in temperature
09:45:13 and filling factor, etc.
09:45:17 And there, you know, until until we have the observational constraints.
09:45:23 I don't know how we can get there without the observational constraints.
09:45:27 But I was going to make a larger point about returning to Dylan's point about the simulations which were amazing.
09:45:39 What we need to be able to do is, is crank various parameters and the simulations and including non equilibrium ionization, including, you know, all sorts of micro physics and, and very them and then do the forward modeling and make comparisons to the
09:45:56 data.
09:45:58 And either drive us to get more data or or drivers to select them on those theories and I guess I wonder to what extent are we now able to do. I was, I was very amazed by this discussion of genetic modification, because I know you can't do a million numerical
09:46:14 simulations, but can you do something where you're changing a few parameters, the illumination you know where the photons coming from which is one of the big questions.
09:46:26 ionization balances, things like that, and compare and then doing the forward modeling, to try to constrain those kinds of models.
09:46:36 That's a great idea. I personally love the genetic modification technique and simulations I've been working a little with Andrew Johnson and Tom Quinn on that which the Tanga simulations have that genetic modification built in, and it allows you to do
09:46:52 these kind of controlled experiments where you hold everything else constant including like the big you know cosmological context of a particular zoom in galaxy.
09:47:01 And you very just one thing right. As of right now the things that you can vary are kind of limited so you can't very exactly how ionization is happening or like the cooling function but I bet you that we could change that.
09:47:15 So, it seems like there's another issue that everyone's making predictions about the admission in residence lines and pretending that you can treat them as optically thin all except for alignment alpha and magnesium to, but I think you're going to have,
09:47:32 But I think you're going to have, you know, we know that lines of sight, through galaxies and all red shifts that are when the galaxies are forming stars have a lot of strong oxygen six absorption which means you're not going to see an adulterated admission
09:47:49 signal in oxygen six from that Halo and so far. That's what all the predictions are based on treating them as optically thin when we know they're not.
09:48:03 Yes, indeed.
09:48:06 All right, I'm going to pivot a little bit from, from a mission, and move on to something that has four thumbs up on the slack and that's something that I put in there but I would just want to spend a little time you know Chris had this wonderful chart
09:48:20 in his talk that brought up this idea of the possible Halo scaling relations, you know after after you do the, the galaxy, you know, global scaling relations and and some seemed more straightforward than others and some also seemed like we already kind
09:48:35 of know like surface brightness versus stellar mass and the Halo.
09:48:39 There's also wrong memorialize work on this fundamental plane and live an alpha absorption.
09:48:46 But of course we've heard in this conference that mass medalist, it might be.
09:48:51 Thumbs down.
09:48:52 But I'm interested to hear you know about these global correlations and in addition.
09:49:02 Something that.
09:49:02 That is probably true that Dylan brings up, understanding them require unbiased surveys what kind of plans do we have for these kinds of unbiased surveys and to probe the scaling relations so anybody can jump in panelists have priority.
09:49:23 Sorry I got distracted by a guinea pig wizard costume but I Batman.
09:49:29 Perfect.
09:49:32 guinea pigs are cute. All right, global scaling relations surely somebody has something to say about global scaling relations and the Halo.
09:49:40 What was that first one that you showed Chris I didn't quite understand what all of those terms were was that like wind loading versus something what was that you're talking about the table I showed yeah I'm a table Oh, these are just.
09:49:55 These are just me speculating okay so this but, You know,
09:50:05 I you know I love you know everyone loves totally Fisher favorite Jackson and so you expect mass velocity correlations.
09:50:15 And of course there is a correlation between how slow velocity and specific star formation rate.
09:50:25 And
09:50:25 I don't know about mass loading, that's complicated so.
09:50:30 But, yeah, it's, I was really trying to get at this idea that you know I remember there was a discussion one of the weeks about our halos simpler than stars.
09:50:42 And, you know, stars have a very simple scaling relationship, galaxies have many simple scaling relationships, and
09:50:52 there, there's, you know sometimes when I talk about the, the, do you know for example, the halo mission we would propose to look at hundreds of galaxies.
09:51:02 And people will say well how can you determine all these things from hundreds of galaxies, and I would make the argument that well we look at many astrophysics phenomena, they have they have much less dimensionality than the number of parameters for example,
09:51:14 Crystal showed this wonderful function of all the parameters. On the other hand, we kind of live and die by the fact that the dimensionality is a lot lower than, then, then, 10 parameters, you know 10 dimensional space.
09:51:28 So, because of conservation laws and other things and I think if you look at the simulations, with that kind of idea in mind you might find some, some scaling things.
09:51:39 I think some people found those that that reflect that. So that's it was just something to stimulate conversation.
09:51:47 Yeah, I crystal, you're unmuted. Sounds like maybe you have something to say.
09:51:54 I was going to suggest that maybe Chris put that slide back up conversation.
09:51:59 Okay, good,
09:52:03 good, good idea, Chris, it can you do that easily. Yeah, I think so. Great.
09:52:11 Yeah, I liked that slide and I had kind of wish that it had stayed up a little bit longer. Well that, yeah.
09:52:19 Talks always go fast.
09:52:22 Okay. I like this slide to
09:52:26 you guys deserve it. Um, Let's see.
09:52:35 You see that. Yeah, perfect. And so, it's just this is total speculation. But then I showed maybe an example of number one, and sort of number two.
09:52:52 And speaking to your idea of doing this work at low redshift and high redshift and, you know, I showed examples of like one possible path forward to get a large sample of galaxies that's hopefully representative of the population and high redshift but
09:53:06 yeah just to emphasize how many of these parameters, you know are going to look way different at low redshift and we already know they do, right.
09:53:15 I guess maybe to follow up on that point Joe a little bit, and maybe this is just, you know, I spend a lot of time going back and forth between kind of the obviously inherent value of scaling laws as tools, and also sort of the temptation to use them
09:53:30 as ground truths. And I think a lot about like this mechanic up lon had different things go once we start doing integral field work. And when we start resolving the physics that are happening on the ground and so I guess I go back and forth a lot about
09:53:43 about scaling laws as guides, So I run one has his hand up.
09:53:47 Yeah, man.
09:53:49 I just want to mention that they're obviously everybody knows how beneficial, or useful scaling laws are one reason why we haven't galaxies is because of surveys like SPSS we have millions of objects.
09:54:02 So perhaps a big step would be with perhaps a few studies or Roman telescope or you played once they have millions of galaxies being survey will have big enough sample to actually you know have better tools to explore these skills like the basic arguments
09:54:21 we put forward like, perhaps there's a correlation offline law for kinematics and healing mass. These are based on still small numbers statistics so the doors things definitely need to explore more.
09:54:32 I think that's a great idea, and definitely something we should all think about seriously.
09:54:39 Agree.
09:54:40 Okay if nobody has anything else to say about scaling relations. Somebody put a comment and I'm trying to find it again I think it's Claudia.
09:54:56 Carney, whose name I'm always feeling wrong I'm so sorry oh no not about the lion, sorry. Somebody mentioned something about wanting to hear more about Mira, and I can, I yeah you on you mentioned that he said I want to hear more about Mira showed up
09:55:03 on one of the slides. Can Can anybody hear talk about Mira, talking about the star Myra Myra sorry See I even said it wrong, can you hear more about Mayra you I can talk about Mayra.
09:55:17 I mean it's been delightful for such a long time.
09:55:20 Yes, it's one of the old difference oh yeah it's an example of a star that's been known for 400 years to be a very, very variable star and only when galaxy launched and happened to look at it just happened to be in the edge of the field of view and Carl
09:55:39 Forster pointed out to me and I said well let's point at it, it turned out it had this beautiful tail, and it is, it's an ag because it's in a TV star with a wind.
09:55:51 But it's moving in very high velocity. So there's a turbulent wake, which is emitting we believe in molecular hydrogen fluorescence.
09:55:59 But we could prove that with Halo.
09:56:03 By taking a spectrum of it and it will feel spectrum it's low surface brightness, but it shows turbulence it shows shows about shock and H alpha but most of the most of this to degree long tail.
09:56:15 Only emits in the Pharrell to our band.
09:56:21 And so it's a fascinating subject turns out their number of objects that produce only Pharrell to violet Nebula or mission, like the blue Ring Nebula we just carry hardly just let a paper on that nature, this this year.
09:56:36 So, it's one of those phenomena that that was not predicted, and it was found. Totally by by observation. So, I love, I love that.
09:56:51 Okay. And then the last thing I'll just end on in the last few minutes that we have here is actually not a comment from the future observations channel but it's one that's on the new instruments channel but I think it's relevant for all of us here, which
09:57:05 is by Dennis Zaretsky noting that, you know, many of the capabilities that are just about to come online aren't super obvious for CGM work, but could actually be used for CGM work if we're creative.
09:57:22 I wonder if anybody here, you know wants to talk about some of the new instruments that are, that didn't have the killer app for CGM science, if they have any plans to kind of use, use them for CGM science, even if it's like a planet instrument or just
09:57:40 instrument.
09:57:44 Go ahead and raise your hand if you have any thoughts on this one of the examples Dennis gave was Desi spectroscopy.
09:57:53 He and he won't even saying at University of Arizona has been doing really interesting things well you know I am part of this work too so I'm a little biased, I should say.
09:58:02 But there are there are stalking you know SDS sh alpha emission and to understand what's going on in each alpha mission and the halos of low redshift galaxies, and it's super interesting this stuff that they're finding I think, not, not a lot of people
09:58:17 are citing that work yet just because I think it's so groundbreaking and so different from things that other people are doing.
09:58:25 I mean I did make a joke earlier but I will say there's there's clearly shared cause between, you know, as you can see from the justifications for how backs and for loop or that there is overlap between what we're doing actually what's happening and exoplanets
09:58:39 especially atmospheres, there I think there is a lot of common cause there that we can build on.
09:58:44 Yeah.
09:58:45 Yeah, I was kind of the token CGM person on the, on the habit science team so I got to think about some of the things that one could do for CGM science using habits and it turns out you know quite a bit.