2001/05/07 by Masako Yamada, Yutaka Fujita · 1 citation
Physics and Astronomy · #Astrophysics #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Cosmic microwave background #Electron #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Intracluster medium #Jet (fluid) #Mechanics #Nuclear physics #Optics #Physics #Radio galaxy #Redshift #astro-ph
paper · pdf · doi:10.1086/320674
10 pages including 2 figures, accepted for publication in ApJL
arxiv created 2001/05/07 · openalex publication_date 2001/06/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the nongravitational heating of hot gas in clusters of galaxies (the intracluster medium [ICM]) on the assumption that the gas is heated well before cluster formation ("preheating"). We examine the jet activities of radio galaxies as the sources of excess energy in the ICM, and we examine the deformation of the cosmic microwave background (the Sunyaev-Zeldovich effect) by hot electrons produced at the jet terminal shocks. We show that the observed excess entropy of the ICM and the COBE /FIRAS upper limit for the Compton y -parameter are compatible with each other only when the heating by the jets occurs at relatively small redshifts ( z ≲ 3). Since this result contradicts the assumption of preheating, it suggests that the heating occurred simultaneously with or after cluster formation.