A BeppoSAX Observation of the IC1262 Galaxy Cluster

Abstract

We present an analysis of BeppoSAX observations of the IC1262 galaxy cluster and report the first temperature and abundance measurements, along with preliminary indications of diffuse, nonthermal emission. By fitting a 6' (~360 h_50^-1 kpc) region with a single Mewe-Kaastra-Liedahl model with photoelectric absorption, we find a temperature of 2.1 - 2.3 keV, and abundance of 0.45 - 0.77 (both 90% confidence). We find the addition of a power-law component provides a statistically significant improvement (F-test = 90%) to the fit. The addition of a second thermal component also improves the fit but we argue that it is physically implausible. The power-law component has a photon index (Gamma_X) of 0.4 - 2.8 and a nonthermal flux of (4.1 - 56.7) x 10-5 photons cm^-2 s^-1 over the 1.5 - 10.5 keV range in the Medium Energy Concentrator spectrometer detector. An unidentified X-ray source found in the ROSAT High Resolution Imager observation (~0'.9 from the center of the cluster) is a possible explanation for the nonthermal flux; however, additional evidence of diffuse, nonthermal emission comes from the NRAO VLA Sky Survey and the Westerbork Northern Sky Survey radio measurements, in which excess diffuse, radio flux is observed after point-source subtraction. The radio excess can be fitted to a simple power law with a spectral index of ~1.8, which is consistent with the nonthermal X-ray emission spectral index. The steep spectrum is typical of diffuse emission and the size of the radio source implies that it is larger than the cD galaxy and not due to a discreet source.

References in corpus (15)

• On The Non Thermal Emission and Acceleration of Electrons in Coma and Other Clusters of Galaxies
• X-ray Properties of Groups of Galaxies
• The intragroup medium in loose groups of galaxies
• Hard X-Ray Radiation in the Coma Cluster Spectrum
• Halo and Relic Sources in Clusters of Galaxies
• A Cluster Merger and the Origin of the Extended Radio Emission in Abell 3667
• Correlation of the magnetic field and the intra-cluster gas density in galaxy clusters
• The peculiar motions of early-type galaxies in two distant regions - VII. Peculiar velocities and bulk motions
• Hard X-ray emission from the galaxy cluster A2256
• The peculiar motions of early-type galaxies in two distant regions - II. The spectroscopic data
• High- and low energy nonthermal X-ray emission from the cluster of galaxies A 2199
• The non-thermal radiation - Cluster merger connection
• BeppoSAX - ROSAT PSPC observations of the Shapley Supercluster: A3562
• Detection of Excess Hard X-ray Emission from the Group of Galaxies HCG62
• X-ray Constraints on Cluster Magnetic Fields

Cited by in corpus (8)

• Testing the Low-Mass End of X-Ray Scaling Relations with a Sample of Chandra Galaxy Groups
• Heating and Acceleration of Intracluster Medium Electrons by Turbulence
• An Objective Survey of Mpc-Scale Radio Emission in 0.03<z<0.3 Bright X-ray Clusters
• Analysis and Interpretation of Hard X-ray Emission from the Bullet Cluster (1E0657-56), the Most Distant Cluster of Galaxies Observed by RXTE
• AGN Feedback in galaxy groups: a detailed study of X-ray features and diffuse radio emission in IC1262
• Evidence of unrelaxed IGM around IC1262
• Diffuse Non-thermal X-ray Emission: Evidence for Cosmic-ray Acceleration at the Shock Front in IC1262
• A Soft X-ray Component in the Abell 754 Cluster