X-TRA: A Template-based Approach for Modeling X-ray Survey Yields of Groups and Clusters

X-TRA - X-ray Template Realization Algorithm - a template approach to realizing large-scale, synthetic X-ray emission maps from groups and clusters of galaxies. The method applies scaling relations and template emission shapes to an input set of halo masses and redshifts (derived from N-body simulation lightcone outputs), producing raw surface brightness maps in the X-ray wavelength. The approach offers a fast, flexible means to characterize transfer functions and systematic error sources in X-ray surveys.

Installation

First, clone the repo with

$ git clone "https://github.com/afarahi/XXX.git"

The code is developed in Python 2.7, so should work out of the box, if you have standard astrophysical libraries installed already.

The dependencies are numpy, matplotlib, and astropy libraries.

Running

Running the code is simple.

1. First, the user need to specify the input/output directories.

   Directories.json specifies where the code need to look for input catalog and where it saves the outputs. Halo-dir in the input directory for the halo catalog. Cluster_dir is where it saves the cluster catalog after assigning the Luminosity, Temperature, and flux. SB_Map_dir is where it saves the surface brightness maps, and finally Event_Map_dir is where it saves the mocked event files.

2. python main.py 1 [input-filename] : make the cluster catalog and save the output at Cluster_dir

3. python main.py 2 [input-filename] : read the cluster catalog from Cluster_dir and makes the surface brightness map and save it as a fit file at SB_Map_dir

4. python main.py 3 [input-filename] : read the surface brightness map and produces tiled synthetic images of noised XMM exposures

Specifying Model Parameters

1. ./parameters/Cosmological_Parameters.json : specifies the cosmological parameters. It will be used as reference and to calculate the evolution factor and the angular distance.

2. ./parameters/Input_Parameters.json : specifies the free parameters of the model, e.g. scaling relation, the surface brightness profile shape. For more detail look at the documentation provided at ./parameters/Input_README.md.

3. ./parameters/Map_Parameters.json : specifies the scales of surface brightness maps. For more detail look at the documentation provided at ./parameters/Map_README.md.

4. ./parameters/Event_Map_Parameters.json : specifies the tiling scheme and the exposure time. For more detail look at the documentation provided at ./parameters/Event_Map_README.md.

Caveats

• The current version of the code expects the surface brightness maps be in unit of [ergs/s/cm^2/pixle] in soft band [0.5-2.0] keV in order to make the event maps. If the user does not want to generate the event maps, then any unit or X-ray band would works fine.

• The current version of the code assumes a 256 x 256 pixel paintings with 4.3" resolution. The event map properties are fixed. If you are interested in different setting the best way would be reaching out to Arya Farahi, aryaf@umich.edu.

Using code

We are glad, you're interested in using code to X-TRA. If there is anything we can help you with feel free to reach us at aryaf@umich.edu for any question or request.

If you want to modify the code for your own purpose, we would much rather you email us asking to collaborate than modify the code as a black box.

License

This project is licensed under the terms of the MIT license.

Citation

Please cite XXX, if you make use of these codes in your work. It is appreciated if you email aryaf@umich.edu to tell us that you are using it.