2008/02/29 by A. A. Lutovinov, A. Lutovinov, A. Vikhlinin +6 · 3 citations
Chemistry · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Chemistry #Cluster (spacecraft) #Coma (optics) #Coma Cluster #Field (mathematics) #Flux (metallurgy) #Galaxy #Galaxy cluster #Gamma-ray bursts and supernovae #Optics #Photon #Physics #ROSAT #astro-ph
paper · pdf · doi:10.1086/592032
submitted to ApJ; slightly expanded version in response to comments from the referee and community
arxiv created 2008/05/19 · openalex publication_date 2008/10/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present results of X-ray observations of the Coma Cluster with multiple instruments over a broad energy band. Using the data from the INTEGRAL , RXTE , and ROSAT observatories, we find that the Coma spectrum in the 0.5–107 keV energy band can be well approximated by a thermal plasma emission model with a temperature of T = 8.2 keV. INTEGRAL was used to image the cluster emission in the hard energy band. The cluster is only marginally detectable (~1.6 σ) in the 44–107 keV energy band; however, the raw flux in this band is consistent with the previous results from the BeppoSAX and RXTE observatories. We can exclude with high significance that the hard-band flux reported by BeppoSAX and RXTE could be produced by a single point source. The 20–80 keV flux of a possible nonthermal component in the cluster spectrum is (6.0 ± 8.8) × 10 −12 ergs cm −2 s −1 . Using the upper limits on nonthermal flux, we obtain a lower limit on magnetic field of 0.1-0.2 μG (depending on the spatial model for a smoothly varying field). We also present a temperature map of the central part of the cluster, which shows significant variations and, in particular, a hot ~11.5 keV region in the extension toward the subcluster infalling from the southwest.