2002/10/01 by Yu-Ying Zhang, Yu‐Ying Zhang, Xiang-Ping Wu +1 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Cluster (spacecraft) #Entropy (arrow of time) #Galaxies: Formation, Evolution, Phenomena #Hydrostatic equilibrium #Principle of maximum entropy #Radiative cooling #Radiative transfer #Redshift #Spectral density #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/345390
published as Astrophys.J. 583 (2003) 529-534 · 16 pages, 3 figures, uses aastex.cls. ApJ accepted
arxiv created 2002/10/01 · openalex publication_date 2003/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Recently, the entropy excess detected in the central cores of groups and clusters has been successfully interpreted as being due to radiative cooling of the hot intragroup/intracluster gas. In such a scenario, the entropy floors S\rm floor in groups/clusters at any given redshift are completely determined by the conservation of energy. In combination with the equation of hydrostatic equilibrium and the universal density profile for dark matter, this allows us to derive the remaining gas distribution of groups and clusters after the cooled material is removed. Together with the Press-Schechter mass function we are able to evaluate effectively how radiative cooling can modify the predictions of SZ cluster counts and power spectrum. It appears that our analytic results are in good agreement with those found by hydrodynamical simulations. Namely, cooling leads to a moderate decrease of the predicted SZ cluster counts and power spectrum as compared with standard scenario. However, without taking into account energy feedback from star formation which may greatly suppress cooling efficiency, it is still premature to claim that this modification is significant for the cosmological applications of cluster SZ effect.