2006/06/02 by T. E. Jeltema, T. Jeltema, John S. Mulchaey +6 · 3 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/506372
published as Astrophys.J.649:649-660,2006 · 31 pages, 13 figures, accepted to ApJ for version with full resolution figures see http://www.ociw.edu/~tesla/midzgroups.ps.gz
arxiv created 2006/06/02 · openalex publication_date 2006/09/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We have undertaken a multiwavelength project to study the relatively unknown properties of groups and poor clusters of galaxies at intermediate redshifts. In this paper, we describe the XMM-Newton observations of six X-ray-selected groups with 0.2 < z < 0.6. The X-ray properties of these systems are generally in good agreement with the properties of low-redshift groups. They appear to follow the scaling relations between luminosity, temperature, and velocity dispersion defined by low-redshift groups and clusters. The X-ray emission in four of the six groups is also centered on a dominant early-type galaxy. The lack of a bright elliptical galaxy at the peak of the group X-ray emission is rare at low redshifts, and the other two groups may be less dynamically evolved. We find indications of excess entropy in these systems over self-similar predictions out to large radii. We also confirm the presence of at least one X-ray-luminous AGN associated with a group member galaxy and find several other potential group AGNs.