2009/12/21 by Adrienne M. Juett, David S. Davis, Richard Mushotzky · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Calibration #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy cluster #Hydrostatic equilibrium #Observable #Observational study #Scaling #Scientific Research and Discoveries #Virial mass #Virial theorem #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1088/2041-8205/709/2/l103
14 pages, 3 figures, Accepted for publication in the Astrophysical Journal Letters
arxiv created 2009/12/21 · openalex publication_date 2010/01/11 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the mass–X-ray observable scaling relationships for clusters of galaxies using the XMM-Newton cluster catalog of Snowden et al. Our results are roughly consistent with previous observational and theoretical work, with one major exception. We find two to three times the scatter around the best-fit mass scaling relationships as expected from cluster simulations or seen in other observational studies. We suggest that this is a consequence of using hydrostatic mass, as opposed to virial mass, and is due to the explicit dependence of the hydrostatic mass on the gradients of the temperature and gas density profiles. We find a larger range of slope in the cluster temperature profiles at r 500 than previous observational studies. Additionally, we find only a weak dependence of the gas mass fraction on cluster mass, consistent with a constant. Our average gas mass fraction results argue for a closer study of the systematic errors due to instrumental calibration and analysis method variations. We suggest that a more careful study of the differences between various observational results and with cluster simulations is needed to understand sources of bias and scatter in cosmological studies of galaxy clusters.