Access Restriction

Author Majumdar, S. ♦ Nath, B. B.
Source Indian Institute of Astrophysics
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Galaxies: Cooling Flows ♦ Cosmology: Cosmic Microwave Background ♦ Cosmology: Distance Scale ♦ Galaxies: Clusters: General ♦ Cosmology: Large-Scale Structure of Universe
Description We study the effect of cooling flows in galaxy clusters on the Sunyaev-Zeldovich (SZ) distortion and the possible cosmological implications. The SZ effect, along with X-ray observations of clusters, is used to determine the Hubble constant, H0. Blank-sky surveys of SZ effect are being planned to constrain the geometry of the universe through cluster counts. It is also known that a significant fraction of clusters have cooling flows in them, which change the pressure profile of intracluster gas. Since the SZ decrement depends essentially on the pressure profile, it is important to study possible changes in the determination of cosmological parameters in the presence of a cooling flow. We build several representative models of cooling flows and compare the results with the corresponding case of gas in hydrostatic equilibrium. We find that cooling flows can lead to an overestimation of the Hubble constant. Specifically, we find that for realistic models of cooling flow with mass deposition (varying m with radius), there is of the order of ~10% deviation in the estimated value of the Hubble constant (from that for gas without a cooling flow) even after excluding ~80% of the cooling-flow region from the analysis. We also discuss the implications of using cluster counts from SZ observations to constrain other cosmological parameters in the presence of clusters with cooling flows.
ISSN 0004637X
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Institution The American Astronomical Society
Starting Page 1