Power spectra and covariance of the SO simulations

This page describes how to use the scripts in https://github.com/simonsobs/PSpipe/tree/master/project/AnalyseSims to get power spectra and covariance matrices of the SO official simulations using PSpipe.

The SO simulations are produced by Andrea Zonca using mapsims: https://github.com/simonsobs/mapsims

and are documented in : https://mapsims.readthedocs.io/en/latest/

They contain:

• Noise simulations generated using the SO_noise_calculator.
• Extra-galactic simulations generated using WebSky: https://mocks.cita.utoronto.ca/index.php/WebSky_Extragalactic_CMB_Mocks
• Galactic simulations generated using PySM: https://github.com/bthorne93/PySM_public

The power spectrum and covariance pipeline is divided into four different steps that should be run sequentially (you need to have pspy installed first)

• combine_sims.py : coadd the simulations together
• sim_window_and_bbl.py : compute window functions and mode coupling matrices
• sim_spectra.py : compute all cross power spectra
• sim_covariance.py : compute all covariance matrix elements

The rational for the division in 4 steps is the following:

• You need to combine the simulations once per set of simulations
• You need to compute the mode coupling matrices once for each new set of window function (so mask/hitcount)
• if you change simulation/window function you will have to recompute spectra
• if you have new spectra you have to recompute the covariance

In the following links, we describe each steps in details and how to run them on the NERSC CORI cluster:

https://github.com/simonsobs/PSpipe/wiki/combine_sims.py https://github.com/simonsobs/PSpipe/wiki/sim_window_and_bbl.py https://github.com/simonsobs/PSpipe/wiki/sim_spectra.py https://github.com/simonsobs/PSpipe/wiki/sim_covariance.py