Chandra X-Ray Detection of the Radio Hotspots of 3C295

D. E. Harris, P. E. J. Nulsen, T. P. Ponman, M. Bautz, R. A. Cameron, L. P. David, R. H. Donnelly, W. R. Forman, L. Grego, M. J. Hardcastle, J. P. Henry, C. Jones, J. P. Leahy, M. Markevitch, A. R. Martel, B. R. McNamara, P. Mazzotta, W. Tucker, S. N. Virani, J. Vrtilek

Published 1999-11-19Version 1

An observation of the radio galaxy 3C295 during the calibration phase of the Chandra X-ray Observatory reveals X-ray emission from the core of the galaxy, from each of the two prominent radio hotspots, and from the previously known cluster gas. We discuss the possible emission processes for the hotspots and argue that a synchrotron self-Compton model is preferred for most or all of the observed X-ray emission. SSC models with near equipartition fields thus explain the X-ray emission from the hotspots in the two highest surface brightness FRII radio galaxies, Cygnus A and 3C295. This lends weight to the assumption of equipartition and suggests that relativistic protons do not dominate the particle energy density.