2002/07/11 by Joshua C. Kempner, Joshua Kempner, Craig L. Sarazin +3 · 4 citations
Physics and Astronomy · #Astrophysics #Atmospheric sciences #Cluster (spacecraft) #Cold front #Core (optical fiber) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Gamma-ray bursts and supernovae #Halo #Intracluster medium #Magnetic field #Optics #Physics #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/342748
published as Astrophys.J. 579 (2002) 236-246 · Accepted for publication in ApJ. 10 pages, 9 figures (3 color), uses emulateapj5. For version with high resolution figures, see http://www.astro.virginia.edu/~jck7k/research/papers/A85_south.ps.gz
arxiv created 2002/07/11 · openalex publication_date 2002/10/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present an analysis of a highly asymmetric cluster merger from a Chandra observation of A85. The merger shows significant disruption of the less massive subcluster from ram pressure effects. Nevertheless, a cold core, coincident with the cD galaxy, is observed to persist in the subcluster. We derive dynamical information from the motion of the cold core through the main cluster's intracluster medium. Multiple derivations of the velocity of the core suggest a Mach number of ≈ 1.4, or v ~ 2150 km s -1 , although with substantial uncertainty. We construct a consistent kinematic model for the merger based on this dynamical analysis. As has been found for other such "cold fronts," conduction appears to be suppressed across the front. Thermal conduction may be suppressed by a magnetic field with a significant component perpendicular to the subcluster's direction of motion. The effect of the merger interaction in creating and shaping the observed radio sources is also discussed. It appears most likely that the radio source is due to distorted and detached lobes from the subcluster cD galaxy, rather than being a radio halo.