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Generating SZ Profiles
By Jackson O'Donnell.
The core of the Y3 clusters analysis uses weak lensing profiles to calibrate cluster masses. We can also, however, cross-correlate with the signal cluster imprint on the CMB through the Sunyzev-Zeldovich effect.
The observable we use for this is the Compton-y parameter, a function of the integrated line-of-sight electron pressure. There is a test module in our code which generates expeccted Compton-y profiles in specific mass, redshift bins. This is a tutorial on how to run it.
Inside the docker image (or on your machine if you're running locally),
# Install colossus - needed to convert between cluster mass definitions
$ pip install colossus==1.2.11
$ pushd /tmp
# Install JOD's cluster_toolkit - contains pressure profiles
$ git clone https://github.com/jhod0/cluster_toolkit
$ pushd cluster_toolkit
$ git checkout pressure-profiles
$ python setup.py install
$ pushd $COSMOSIS_SRC_DIR/cosmosis-standard-library/
# Now install the clustef_toolkit cosmosis wrapper into a directory called "cluster-sz"
$ git clone https://github.com/jhod0/cosmosis-cluster-sz cluster-sz
$ popd; popd; popd
This installs two python modules we need (colossus and my version of cluster_toolkit), as well as a cosmosis module wrapping cluster_toolkit.
There is a test module using the C++ integration framework in src/modules/compton_y_sims.cc, with a corresponding .ini file.
It computes the expected Compton-y parameter profiles in bins of mass and redshift, for a grid of angles from the cluster center. You can use it as a baseline to create a more complex module, e.g. one incorporating a mass-observable scatter, triaxiality effects, etc.
$ cd $COSMOSIS_SRC_DIR/y3_cluster_cpp
$ cosmosis cosmmosis_tests/compton_y_sims.ini