Baryon Pasting Algorithm: Halobased and Particlebased Pasting Methods
Abstract
We present a fast methodology to produce mock observations of the thermal and kinetic SunyaevZel'dovich (SZ) effects based on dark matter only $N$body simulations coupled with the analytic intracluster medium model. The methods employ two different approaches: halobased pasting (HP) and particlebased pasting (PP). The former pastes gas density and pressure onto halos and requires only halo catalogue, and the latter also considers contribution from field particles as well, i.e., particles which do not belong to any halos, and thus utilises the full particle information. Therefore, the PP algorithm incorporates secondary effects beyond the HP algorithm: asphericity of halos and contribution from diffuse gas. In particular, such diffuse component is the dominant source of the kinetic SZ effect. As validation of our methods, we have produced 108 allsky maps with HP and 108 flatsky maps which cover $5 \times 5 \, \mathrm{deg}^2$ with both of HP and PP. Our method can produce a mock map within a few hours even for allsky coverage with parallel computational environment. The resultant power spectra of these maps are consistent with theoretical predictions. We discuss the utility of baryon pasted mock SZ maps for estimating the covariance matrix of crosscorrelation between SZ effects and other largescale structure probes as well as modelling the selection and projection effects for cluster cosmology.
 Publication:

arXiv eprints
 Pub Date:
 January 2022
 arXiv:
 arXiv:2201.02632
 Bibcode:
 2022arXiv220102632O
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 13 pages, 9+1 figures, submitted to MNRAS, data available at https://github.com/0satoken/BP_SZ_maps