plot profiles and compare NFW profile

[evavagiakis]

@antwinew1401 could you work on a notebook that:

1. Plots Battaglia profiles for varying z, M, and put those profiles side by side with the Battaglia 2012 plots for visual comparison
2. Plots an NFW profile from an existing python model such as https://docs.astropy.org/en/stable/api/astropy.modeling.physical_models.NFW.html for a given halo (z, M) and compares that profile to a Battaglia profile

Elaine has begun looking into NFW profiles so she may be able to look at this as well

[bnord]

Is there a notebook or script in our repo to start with?

[evavagiakis]

Antwine has been working with a notebook to do this already.

[antwinew1401]

two different results I got when plotting gNFW profile for battaglia's pressure profile. I think I'm getting closer, but I also think I need to do a little bit more reading

[antwinew1401]

I think this gNFW works best with the pressure profile from battaglia. I changed P0 to Pth_rescaled in gNFW equation and changed the parameters alpha to -0.006 and gamma to -0.01.

[bnord]

What does this mean? " gNFW works best with the pressure profile from battaglia"

That is, when would gNFW not be used with the pressure profile?

[antwinew1401]

My apologies, I could've worded this better. I mean that this gNFW model is specifically designed to approximate the pressure profiles derived from simulations that is proposed by Battaglia. The model assumes a specific form for the pressure profile based on the NFW profile, the gNFW introduces additional parameters to better match the observed pressure profiles of galaxy clusters. I think the gNFW wouldn't work if there are deviations from hydrostatic equilibrium because gNFW is derived assuming hydrostatic equilibrium within the clusters. I also do think gNFW would work if magnetic fields plays a dominant role in determining the pressure profile.

[bnord]

roger that. thanks for explaining.

[evavagiakis]

Thanks @antwinew1401, could you please link your repo/point to the gNFW plotting function and the equations from papers you used to write it?

[antwinew1401]

Yes you can find this notebook in the physics-tests branch in the folder 'Antwine-sims'. The notebook is titled 'Antwinesim.ipynb' (I can rename this if needed). The gNFW plotting function is named gNFW and the equation I used to write it is eq. 10 from Battaglia.

[evavagiakis]

Thanks Antwine, it looks like this is the same Battaglia profile we've been discussing. The Battaglia profile is generated using param_Battaglia2012() and Pth_Battaglia2012() in https://github.com/deepskies/SimSZ/blob/dev-massdist/make_sz_cluster.py which are from equation 10 and table 1 in Battaglia 2012. What we want to have is an independent check on these profiles using a different kind of profile that doesn't depend on these equations. The NFW profile would be an independent check on this profile by using different equations. Some of the resources I've sent give equations for electron density, and some give ways of converting this to electron pressure. Do you have another idea for how to plot NFW profiles, and if so could you refer to those equations? I'd be happy to hop on a zoom to discuss this further, just let me know.

[bnord]

brief comment about github comments: best practice is to put the hyperlink for any code that you're referencing: since you've been looking at it, it's faster for you to paste the link in than it is for a commenter/reviewer to look for it. It's my everyday practice to put hyperlinks into comments when I want other people to look at them.

[evavagiakis]

Moving NFW profile generation to #152 and closing this issue since we are no longer interested in comparison for alpha release