Is there a hard tail in the Coma Cluster X-ray spectrum?

Abstract

We report results from a re-analysis of the BeppoSAX observation of Coma and from the analysis of a second, yet unpublished observation of the same object. From our re-analysis of the first observation we find that the statistical evidence for a hard tail is about 2 sigma. From the analysis of the second observation which, thanks to the lower background and the longer exposure time, is characterized by a larger signal to noise we find no evidence for a hard tail. From the upper limit on the flux of the hard tail, using the standard Inverse Compton formulae, we derive a lower limit for the magnetic of about 0.2-0.4 microGauss consistent with Faraday rotation measurements.

4 pages, 2 figures, to appear in A&A Letters

References in corpus (8)

• A New Radio - X-Ray Probe of Galaxy Cluster Magnetic Fields
• Hard X-Ray Radiation in the Coma Cluster Spectrum
• XMM- Newton Observation of the Coma Galaxy Cluster: The temperature structure in the central region
• Hard X-ray emission from the galaxy cluster A2256
• Results from a Second RXTE Observation of the Coma Cluster
• Quantification of Uncertainty in the Measurement of Magnetic Fields in Clusters of Galaxies
• Hard X-ray and radio observations of Abell 754
• RXTE and ASCA Constraints on Non-thermal Emission from the A2256 Galaxy Cluster

Cited by in corpus (60)

• Cosmic rays in galaxy clusters and their non-thermal emission
• Diffuse Radio Emission from Galaxy Clusters
• Constrained Simulations of the Magnetic Field in the Local Universe and the Propagation of UHECRs
• Multi-frequency analysis of neutralino dark matter annihilations in the Coma cluster
• Cluster mergers and non-thermal phenomena: expectations from a statistical magneto-turbulent model
• GMRT Radio Halo Survey in galaxy clusters at z = 0.2 -- 0.4. II.The eBCS clusters and analysis of the complete sample
• Acceleration of primary and secondary particles in galaxy clusters by compressible MHD turbulence: from radio halos to gamma rays
• Simulating cosmic rays in clusters of galaxies - II. A unified scheme for radio halos and relics with predictions of the gamma-ray emission
• XMM-Newton Observation of the Northwest Radio Relic Region in Abell 3667
• Alfvenic reacceleration of relativistic particles in galaxy clusters: MHD waves, leptons and hadrons
• Confirmation of non-thermal hard X-ray excess in the Coma cluster from two epoch observations
• Alfvenic reacceleration of relativistic particles in galaxy clusters in the presence of secondary electrons and positrons
• Galaxy Clusters in the Swift/BAT era: Hard X-rays in the ICM
• Chemical evolution in Sersic 159-03 observed with XMM-Newton
• Simulating cosmic rays in clusters of galaxies - III. Non-thermal scaling relations and comparison to observations
• A $\mathcal{M}\gtrsim 3$ shock in `El Gordo' cluster and the origin of the radio relic
• Constraints on the multi-TeV particle population in the Coma Galaxy Cluster with H.E.S.S. observations
• Nonthermal phenomena in clusters of galaxies
• Gamma Rays from Clusters and Groups of Galaxies: Cosmic Rays versus Dark Matter
• Estimating galaxy cluster magnetic fields by the classical and hadronic minimum energy criterion
• Suzaku Observation of the Ophiuchus Galaxy Cluster: One of the Hottest Cool Core Clusters
• Chandra measurements of non-thermal-like X-ray emission from massive, merging, radio-halo clusters
• Heating and Acceleration of Intracluster Medium Electrons by Turbulence
• Hard X-ray Properties of the Merging Cluster Abell 3667 as Observed with Suzaku
• INTEGRAL discovery of non-thermal hard X-ray emission from the Ophiuchus cluster
• A Suzaku Search for Non-thermal Emission at Hard X-ray Energies in the Coma Cluster
• Suzaku Observation of the Radio Halo Cluster Abell 2319: Gas Dynamics and Hard X-ray Properties
• A NuSTAR observation of the center of the Coma Cluster
• Long RXTE Observations of A2163
• Nonthermal hard X-ray excess in the Coma cluster: resolving the discrepancy between the results of different PDS data analyses
• Galaxy Clusters in the Swift/BAT era II: 10 more Clusters detected above 15 keV
• Extended X-ray emission at high redshifts: radio galaxies versus clusters
• Analysis and Interpretation of Hard X-ray Emission from the Bullet Cluster (1E0657-56), the Most Distant Cluster of Galaxies Observed by RXTE
• N-body + Magnetohydrodynamical Simulations of Merging Clusters of Galaxies: Characteristic Magnetic Field Structures Generated by Bulk Flow Motion
• Nonthermal hard X-ray excess in the cluster Abell 2256 from two epoch observations
• In-situ acceleration of subrelativistic electrons in the Coma halo and the halo's influence on the Sunyaev-Zeldovich effect
• Covariant Kinetic Theory with an Application to the Coma Cluster
• On the small scale turbulent dynamo in the intracluster medium: A comparison to dynamo theory
• The Lack of Diffuse, Nonthermal Hard X-ray Emission in the Coma Cluster: The Swift BAT's Eye View
• South-West extension of the hard X-ray emission from the Coma cluster
• X-ray observations of the Coma Cluster in a broad energy band with INTEGRAL, RXTE, and ROSAT observatories
• Where does the hard X-ray diffuse emission in clusters of galaxies come from?
• Suzaku Observations of Iron K-lines from the Intracluster Medium of the Coma Cluster
• Testing the cosmic ray content in galaxy clusters
• Non-thermal emission in the core of Perseus: results from a long XMM-Newton observation
• Non-thermal X-rays from the Ophiuchus galaxy cluster and dark matter annihilation
• On the ICS interpretation of the Hard X-Ray Excesses in Galaxy Clusters: the case of Ophiuchus
• Coma revealed as an extended hard X-rays source by INTEGRAL IBIS/ISGRI
• Hard X-ray emission from accretion shocks around galaxy clusters
• Beyond the Standard Lore of the SZ effect
• The Swift BAT Perspective on Non-thermal Emission in HIFLUGCS Galaxy Clusters
• An analysis of electron distributions in galaxy clusters by means of the flux ratio of iron lines FeXXV and XXVI
• Clusters of galaxies: setting the stage
• Supermodel Analysis of the Hard X-Ray Excess in the Coma Cluster
• Spectral Analysis of RXTE Observations of A3667
• On the DM interpretation of the origin of non-thermal phenomena in galaxy clusters
• Can electron distribution functions be derived through the Sunyaev-Zel'dovich effect?
• On the influence of high energy electron populations on metal abundance estimates in galaxy groups and clusters
• Suzaku Constraints on the Soft and Hard Excess Emissions from Abell 2199
• Suzaku Observation of Abell 1555 and Abell 1558: Searching for Non-thermal Emission from Large Scale Structure Formation