X-ray observations of the Coma Cluster in a broad energy band with INTEGRAL, RXTE, and ROSAT observatories

Abstract

We present results of X-ray observations of the Coma cluster with multiple instruments over a broad energy band. Using the data from 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 ~1.6sigma in the 44-107 keV energy band; however, the raw flux in this band is consistent with the previous results from Beppo-SAX and RXTE observatories. We can exclude with high significance that the hard-band flux reported by Beppo-SAX and RXTE could be produced by a single point source. The 20-80 keV flux of a possible non-thermal component in the cluster spectrum is (6.0+-8.8)*10**-12 ergs/cm^2/s. It is unlikely that the IC scattering of CMB photons is able to produce hard X-ray flux at these levels, unless the magnetic field strength is as low as 0.2muG. The latter value can be considered as a lower limit on the field strength in Coma. 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 towards the subcluster infalling from the South-West.

arXiv commentsubmitted to ApJ; slightly expanded version in response to comments from the referee and community

References in corpus (23)

• ISGRI: the INTEGRAL Soft Gamma-Ray Imager
• Calibration of the Rossi X-ray Timing Explorer Proportional Counter Array
• Particle reacceleration in Coma cluster: radio properties and hard X-ray emission
• On The Non Thermal Emission and Acceleration of Electrons in Coma and Other Clusters of Galaxies
• Observations of extended radio emission in clusters
• Hard X-Ray Radiation in the Coma Cluster Spectrum
• INTEGRAL/IBIS all-sky survey in hard X-rays
• V0332+53 in the outburst of 2004--2005: luminosity dependence of the cyclotron line and pulse profile
• The diffuse radio emission from the Coma cluster at 2.675 GHz and 4.85 GHz
• Outer Regions of the Cluster Gaseous Atmospheres
• XMM- Newton Observation of the Coma Galaxy Cluster: The temperature structure in the central region
• Confirmation of non-thermal hard X-ray excess in the Coma cluster from two epoch observations
• The spectrum of the cosmic X-ray background observed by RTXE/PCA
• Another Collision for the Coma Cluster
• Is there a hard tail in the Coma Cluster X-ray spectrum?
• Results from a Second RXTE Observation of the Coma Cluster
• Heating and Acceleration of Intracluster Medium Electrons by Turbulence
• Extragalactic source counts in the 20-50 keV energy band from the deep observation of the Coma region by INTEGRAL/IBIS
• Quantification of Uncertainty in the Measurement of Magnetic Fields in Clusters of Galaxies
• In-situ acceleration of subrelativistic electrons in the Coma halo and the halo's influence on the Sunyaev-Zeldovich effect
• South-West extension of the hard X-ray emission from the Coma cluster
• Where does the hard X-ray diffuse emission in clusters of galaxies come from?
• Coma revealed as an extended hard X-rays source by INTEGRAL IBIS/ISGRI

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• Cosmic rays in galaxy clusters and their non-thermal emission
• The Coma cluster magnetic field from Faraday rotation measures
• Acceleration of primary and secondary particles in galaxy clusters by compressible MHD turbulence: from radio halos to gamma rays
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• Baryon Cycles in the Biggest Galaxies
• Constraints on the multi-TeV particle population in the Coma Galaxy Cluster with H.E.S.S. observations
• A Suzaku Search for Non-thermal Emission at Hard X-ray Energies in the Coma Cluster
• Intracluster light in clusters of galaxies at redshifts 0.4<z<0.8
• X-ray Point Sources and Radio Galaxies in Clusters of Galaxies
• Galaxy Clusters in the Swift/BAT era II: 10 more Clusters detected above 15 keV
• Nonthermal emission from clusters of galaxies
• The Lack of Diffuse, Nonthermal Hard X-ray Emission in the Coma Cluster: The Swift BAT's Eye View
• INTEGRAL/IBIS deep extragalactic survey: M81, LMC and 3C 273/Coma fields
• Suzaku Observations of Iron K-lines from the Intracluster Medium of the Coma Cluster
• The diffuse soft excess emission in the Coma cluster from the ROSAT All-Sky Survey
• Investigating the hard X-ray emission from the hottest Abell cluster A2163 with Suzaku
• Hard X-ray emission from accretion shocks around galaxy clusters
• Supermodel Analysis of the Hard X-Ray Excess in the Coma Cluster
• Progressive steepening of the SNR RX J1713.7-3946 X-ray spectrum from XMM-Newton to INTEGRAL
• The Evolution of Radio Galaxies and X-ray Point Sources in Coma Cluster Progenitors Since z~1.2
• Hard X-ray Emission from the NGC 5044 Group
• The Extreme Sky - Seven Years of INTEGRAL