09:30:00 Thank you people one up here we are, it's 930 on the outer, take it away.
09:30:06 All right, thanks Jess.
09:30:09 Yeah, this is a, I'm glad we have the opportunity to do for tutorials.
09:30:15 And I've. I'm glad to be go over glad to be going last because I could listen to the first three so this is the, the best spot, um, all right well today as part of multi-phase week john and I are going to be talking about Ford modeling, your cosmological
09:30:36 simulations into x ray observed both and analyzing them like x ray observers do.
09:30:45 And by the way this is primarily a chance code, and I've been lucky to use it and start a project.
09:30:55 And we'll talk about that.
09:30:57 But I wanted to do some motivation first as to, you know, what are the some of the key questions that we hope to tackle. And this is by, by no means an exhaustive list, but I think this is a good week to talk about this.
09:31:14 So, you know, how does the hype X ray Halo medium influence the cool UV twist phase. I think we are very interested that this week.
09:31:23 What is the medalists at of the X ray CGM I think we will be talking a lot about medalists throughout this whole,
09:31:30 whole program, and this has a lot of implications for the dev team temperature and density and pressure especially that you measure in the of the X ray phase.
09:31:43 This is a fun we should do this as a survey question, at what Halo masters the hot phase made over the cool phase.
09:31:51 And there's always the, the, the, the long lasting missing variants problem in the halo perspective.
09:32:01 Where are the missing barriers are they hot or the ejected from the Halo, or a combination of both.
09:32:07 Um, and this is something question five is something that I'm, you know, and my collaborator really interested in what, where does the hot Halo gas originate from from galactic processes is it feedback ribbon is it associated with, with the barrier and
09:32:34 It definitely is in lower mass galaxies, or is it with Halo processes visualization. And, of course, there's the question of does the hot gas precipitate out of the Halo and does it reach the galaxy just feed galaxy formation and how does that vary with
09:32:45 Halo mass with redshift, etc.
09:32:50 Um, I put this flowchart together without checking with john but this is kind of the idea of what we will be talking about today, where you take a simulation, whether it be gadget, or Arapahoe or Gizmo based simulation and john has works has started working
09:33:14 with Enzo before I ever joined collaborating with him.
09:33:19 And there's a number of other simulations, but generally john has written his software so he can take these different simulation formats in the YT framework.
09:33:30 And he will be talking about high XM.
09:33:34 And that takes these gas, you know, these gashes halos simulations takes their physical data density temperature
09:33:47 abundances and converts them into an X ray photon list. And then there's another step to get to your mock X ray observation. So you have a photon list and jobs code Sox's that, then we'll create yeah take those photons and make a Ford Model observation,
09:34:11 usually with NASA missions existing such as Chandra, or future, hopefully as links.
09:34:28 xmm or Rosita and XM Newton event files, and then you get over here and you have a mock X ray image and events file as is known in the field, which is really just.
09:34:58 All right, deck and energy at the minimum, and then you can apply to all sorts of extra analysis tools to them to make an extra spectra to make actually surface brightness profiles, etc.
09:35:05 So why do we do this.
09:35:09 Well, first I wanted to just say, you might be interested in informed modeling, your own simulation into the X ray. And if you are, please do contact us, you can contact me.
09:35:22 JOHN is very busy with a lot of things and it's awesome to have his time but the pipeline is not yet turnkey, especially for the CGM it's pretty complicated, and we are interested in collaborating and starting new projects so feel free to contact me and
09:35:38 we'll see what we can do. And this is a great time to test start talking about this at this at this program. Um, so, some motivation of like an observation one thing that I've been thinking a lot about.
09:35:52 Recently, is this coach Bugden massive spiral, which has an X ray Halo detected via xmm, and there's data, such as extra surface to private profiles of collapsing that 2d image into a 1d profile and cutting it into like the soft X ray band, and also looking
09:36:13 at the spectrum and fitting that with a medalist city and driving a lot of information about the extra Halo surrounding this spiral galaxy and that's something that is is existing and hasn't been really confronted by simulations yet directly in.
09:36:31 So, you know, thinking along this line I just want to show, sort of, something I'm working on using this pipeline is a taking a simulated spirals from multiple simulations I hear, Dylan will be happy about this I'm showing molesters TNG 100 spiral Halo.
09:36:54 And, you know, this is the gas density.
09:36:58 And you can see it's kind of cut off here it's you know from the, the cosmological volume but like it.
09:37:04 We just grab it from the
09:37:09 tng repository just gives you the halo gas and white he has all this functionality to make an idealized X ray mission map in this case of soft X ray mission map.
09:37:22 But that's not what we're doing, because we are forward modeling through pike Sim, and this case through 60 software, making photon individual photons and those photon lists in the simplifies with john will talk about, and making mock spectra.
09:38:01 have, we know the answer what the medalist it is in these simulations, but we're getting an observer specialist at to see if those those agree with the, what is you know what we know is in the simulation and what an observer will get on the outside so
09:38:18 that's an interesting example because you know I think medalists he is quite, you know, uncertain, often in X ray observations and, you know, and observers metal history maybe his point Wednesday solar and maybe what is in the simulation could be different.
09:38:36 And if there is a, a discrepancy.
09:38:40 That's important because in such a case like there's, you know, most of the X ray soft X ray admission in these galactic halos comes from metal lines like 80 to 90%.
09:38:53 So, if you're medalists you derive is wrong by a factor of, a few, you're in third density is, is, is wrong because, you know, once the solar model will be a lot less dense than a point one z solar model.
09:39:08 So then you're in front pressure of the halo medium impacting the new formation of the cold cool phase tracing the UV will be quite different. And so that's, that's why we are doing this and it'll be an interesting you know project, I think, to discuss
09:39:28 these. So now I'm going to hand it off to john and john you will. We'll just keep this presentation going, and you can tell me, you know, give me a clue to change slides.
09:39:40 Okay, thank you, Ben, and thanks to everyone for having me here. I just want to take a few slides to sort of delve into sort of the algorithms, and the process and the method for creating the synthetic X ray observations, so the basically the bulk of
09:39:59 this is done by a package called pi XM, which band has mentioned, it generates synthetic X ray observations from 3d models so basically this is simulation outputs been given nice list of simulation outputs, or even like say toy models and buy a toy bottle
09:40:17 I mean, let's say you just like take a 3d like non pie array and you fill it with like density temperature medalists at a US set up like a beta model or some strictly symmetric thing or something.
09:40:32 And the way that you can read all of this kinds of data is that it uses the YT package to the handle the 3d data, whether it's like a grids, whether it's a uniform grid or an adaptive mesh refinement grid, or it's a Renault destination like Rambo or it's,
09:40:52 you know, SPH type simulation.
09:40:55 So YT is sort of the lingua franca for all of these different simulations, I don't have a lot of time to go into a full description of it as I'd like in the short amount of time.
09:41:08 But basically, the point is is that allows you it's a it's intended to be a Python package for analyzing all these different types of simulation data and allowing the user to ask, and get answers to physical questions, the Python package itself which
09:41:26 uses YT for all this is based on the original Fox approach of Veronica Biffy at all 2012 2013, which was designed initially for gadget simulations. So then you can go to the next slide.
09:41:42 So this is basically the the fox algorithm adapted for pi XM So pi accent assume you have like a 3d emission model of a source from a simulation, or perhaps just the 3d grid or a collection of particles so basically we're saying that are emitting object
09:42:02 is this case is a sphere the schematic, that, you know, blue circle and that it's filled up with volume elements so right there. I've got a cell but this could be like an seh particle or Verona cell, and that this cell has some properties, this, this,
09:42:21 you know this mass element has some properties so it's got a density a temperature multiplicity.
09:42:26 It's got a position somewhere, it's got a volume obviously and it's got a velocity.
09:42:32 So what pipestem does is is that for each of these little volume elements or mass elements. It takes an addition model. So for example, it could be a thermal emission model, or it could be a power log mission model depending on what the underlying physical
09:42:47 processes, and then you go to the next slide.
09:42:52 And then what it does is it says okay let's assume that we have this really large exposure time. And a really large collect collecting area and large of course is defined here as a comparison to like the instrument that the properties that the estimates
09:43:07 you're interested in simulating.
09:43:10 And then we have like a large exposure time and a large collecting area and then for each one of those little volume elements we generate a number of photons at the position of little volume element.
09:43:33 And we give them the energies from the spectrum. Okay.
09:43:38 So, If you work with x rays you realize that you're not really working in the continuum approximation. I work for Chandra and one of the things that I get to do on call sometime is watch you can actually have a little screen where I could literally watch
09:43:51 events, direct is true events being detected by Chandra one by one for, you know, even faint sources so that's sort of the approach this motivated here is that we generate a large ish Monte Carlo sample of synthetic photons, so you could go back to the
09:44:07 next one.
09:44:10 So then what we do is is that we have this large sample and then we draw a sub sample of this large sample and I forget ahead of myself, I should say, the point is is that you can store this sample to disk.
09:44:21 Okay, so it's a sample in 3d, it's got all the photons have 3d positions, you can save that disk, and then you can project.
09:44:31 This sample along to undo a sky plane, essentially as many times as you want. So the really expensive step generated the photon energies is done and over with you save it to disk.
09:44:42 And then you do the projection. Afterwards, onto a sky planes if you want to look at the same 3d source from lots of different projections, to see what it would look like in those different projection angles.
09:44:54 And what that does is two things that it a of course it projects everything on to it onto the sky plane. And the second thing it does. If you have an instrument that is, that has high enough energy resolution to measure it, is that it picks off the velocity
09:45:10 component along the line of sight, and then Doppler shift every photon in the sample.
09:45:16 And then if you have a cosmological source the photons are cosmological a red shifted.
09:45:21 And with the other things we have to do is is that any source you know outside the ED source that is coming to us is going to have some of its photons absorbed by galactic foreground, so it also takes care of that.
09:45:34 So you can see here that you've got a little model of Chandra there, you know you've got a particular projection.
09:45:41 So then you can go to the next one.
09:45:46 And I should say here, even though I don't have a slide for it. That's where it stops. Okay, so you have a list, essentially that you can write to disk in this format called sim put which writes a photon position or a deck and energy.
09:46:03 And then what happens later, is that either the socks package or the 60 package which we'll talk about in a couple slides can read those in and then involve them with an instrument so there's like a break, basically, because you might want to save this
09:46:15 input catalog disk have all these simulated photons and then say simulate with Chandra or xmm or say, you know, Athena, or links some feature hypothetical mission.
09:46:28 So as far as the types of inputs anything YT could read simulation data sets 3d know high res of grid points or particles type of the admission models that are built in, is a thermal model that uses at MTV or APEC power law model or line emission of course
09:46:51 So Ben I'm going to go ahead to the next.
09:46:55 We're just going to show a few examples. These are the examples I'll show mostly from my work. And these are mostly clusters so they're a bit too big for this workshop, but, you know, you could just sort of imagine scaling these things down.
09:47:10 And so basically what we have here is that we have a couple of slices of density and temperature through a simulation of a galaxy construct core, where the gas is sort of moving around.
09:47:22 We call this sloshing around in this spiral shape, so that you can go to the next one.
09:47:27 And then what pike sim does after going through that pipeline and then involving the list that you get out of the end with a couple of different instruments simulators, is that you can get an image of the photons from that galaxy cluster so on the left
09:47:41 you have a charger image using the HSI imager so you can see the chip gaps and everything in there but you see the sloshing spiral there. And you see that it's very noisy because of course this is, this is x rays.
09:47:57 And, and then you have the Athena image on the right where you can see there's like a different.
09:48:04 There's a different shape of the detector but also it's a lot less noisy because the, the affected area of the Athena mission is just a lot of higher.
09:48:18 However, the point spread function. The angular size of it is about 10 times larger than the genres of course and so the image is also a bit blurry here.
09:48:28 So you go ahead to the next one will go into the a huge amount of detail on this slide, but you can also, if you have a micro Calla perimeter which is basically a specific special type of X ray instrument you can make where you can, you have a imager
09:48:46 that can nevertheless measure velocities.
09:48:52 Really well which is something that most that up till now.
09:48:56 Most Extreme. Extra instruments couldn't do that. And he told me he was able to do it but of course it didn't last very long. So this is an example where we use pie XM to try to measure the velocities and a cluster that was similar to the Perseus cluster
09:49:11 which he told me was able to measure before it bends demise.
09:49:15 So, then you can go next.
09:49:19 And then here is sort of a fun toy example.
09:49:23 This is an example where I took a simulation of a cluster so this is a cluster extracted from a cosmological box and believe this is from one of the fire simulations.
09:49:34 I can't remember exactly. And so we have gas density and dark matter density and then we assume, which is not true. As it turns out, we assume that the dark matter particles are annihilating, and that they produce this huge emission line, which doesn't
09:49:51 actually exist but it's a really interesting toy example. So Ben if you go to the next slide, You can see all the blue stuff is thermal emission from the cluster.
09:50:02 And then, that little orange line right there is actually then addition line that I added that is supposedly coming from like an isolation between dark matter particles.
09:50:15 Now in reality there is no admission line at that location. It would be really cool if there was but it's just an example of something that you can do with PI XM.
09:50:26 So you can go to the next one.
09:50:29 So pay except currently hope it doesn't have this forever currently comes to some limitations.
09:50:36 It assumes that the stuff you're working with is optically thin, so we don't have any optical thickness absorption or scattering.
09:50:50 No, this is something that other wavelengths tried and is really good at a bug Cameron a couple times about this saying we should do this sometime.
09:50:53 It's worth thinking about. Se Cameron, giving me a thumbs up so I definitely think that's something that be good to do at currently doesn't simulate the sources with explicit time dependence that'd be something that might be interesting to do in the future
09:51:06 and then, although maybe not as relevant to this group. And then it also doesn't work with 3d datasets not Cartesian coordinates so that's another feature that will have to come down the road is if you haven't like a cylindrical or a spherical coordinates
09:51:21 simulation.
09:51:22 So go ahead and move.
09:51:25 So, basically, This is a how to get it so or are basically just a couple of notes about it. So, the current stable version of pikes in is 2.3 point oh, which I just mentioned that released this morning, or between last night and this morning.
09:51:43 It depends on YT if you you can install.
09:51:48 We can talk about this more in the breakout session but you can install it using paper Anaconda and pike simple automatically install yd for you if you don't have it but especially if you have SPH data.
09:52:02 I recommend installing YT from source because that will get you the, what is essentially a beta version of YG Port 4.0 which is really really good for the grungy and slash SPH data grid based data works fine and the stable version of YT which is what
09:52:22 3.6 point one but if you really want to hire except to work for
09:52:29 the SPH date I definitely recommend 4.0 pack Sims on GitHub there's a Google group and a mailing list.
09:52:37 And I believe that's my last slide Ben if you could just go to the next one.
09:52:42 All right. I, and I will just, if you don't mind, I'll just make a quick comment about this since this is also my package, and then Ben can also comment here.
09:52:54 Basically socks is a separate package, the two packages are related in fact if you download the pipe summit at install sucks for you because it uses stuff from socks and what sucks does is is that it produces a simplified simulated observations, using
09:53:10 simple models for Chandra, The proposed links.
09:53:14 Athena prism.
09:53:17 I propose mission called access, stuff like that.
09:53:20 And since this is your slide Ben I'm gonna let you take it away but I just thought I'd sort of give us the transition there so okay thank you yeah thanks.
09:53:28 Well, it's your code. So, and also like I should say that this is you know transmedia all these this software publicly available so you're welcome to like download this and do this on your own simulation and.
09:53:40 But, you know, some of the things that I'll show now are a little bit more specific and I'm, I'm interested in collaborating on on things and especially in the CGM and have learned some, you know, from some pitfalls that we've run into.
09:53:58 So So then, do you want to do this in the breakout room it's not to do something else so yeah technically the tutorial recorded time is over but maybe this is good for a breakout session.
09:54:12 Awesome, Thank you guys so much. That's really interesting.
09:54:15 Yeah, I love this sounds like are incredibly useful tool.
09:54:19 Okay, so the the breakout room is open, X ray Ops, I think, you know, everybody can head over there