Diffuse Non-thermal X-ray Emission: Evidence for Cosmic-ray Acceleration at the Shock Front in IC1262

Abstract

We report the first localization of diffuse, non-thermal, X-ray emission from a nearby galaxy cluster. Using Chandra data, we have isolated a diffuse non-thermal X-ray component with a photon index, Gamma_ X = 2.21 +0.14 -0.15 and a flux of 9.5 +1.1 -2.5 x 10^-5 photons cm^-2 s^-1 keV^-1 at 1 keV, that extends from ~1'.5 to ~2'.5 to the south of the X-ray flux peak. Comparison to simulations implies that the diffuse non-thermal emission is produced by primary electrons, accelerated at shocks to relativistic velocities. Using these results and the flux and hardness maps produced with data from the Chandra Advanced CCD Imaging Spectrometer, we conclude that a smaller subclump coming from the north merged with IC1262. The offset of the cD galaxy from the X-ray peak and large peculiar velocity indicate that the subclump's impact parameter was to the west and on the near side of IC1262.

5 pages, 4 figures, 2 tables. Accepted by ApJL

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Cited by in corpus (6)

• Testing the Low-Mass End of X-Ray Scaling Relations with a Sample of Chandra Galaxy Groups
• An Objective Survey of Mpc-Scale Radio Emission in 0.03<z<0.3 Bright X-ray Clusters
• AGN Feedback in galaxy groups: a detailed study of X-ray features and diffuse radio emission in IC1262
• Evidence of unrelaxed IGM around IC1262
• Magnetized matter effects on dilaton photon mixing
• Hard X-ray Emission from the NGC 5044 Group