Generating SZ Profiles

SZ Profiles

By Jackson O'Donnell.

What are they?

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.

What do I need to install?

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.

How do I run it?

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.

$ cd $COSMOSIS_SRC_DIR/y3_cluster_cpp
$ cosmosis cosmmosis_tests/compton_y_sims.ini