The X-ray spectrum and light curve of Supernova 1995N

We report on multi-epoch X-ray observations of the Type IIn (narrow emissio n line) Supernova (SN) 1995N with the ROSAT and ASCA satellites. The 1998 J anuary ASCA X-ray spectrum is well fitted by a thermal bremsstrahlung (kT s imilar to 10 keV, N-H similar to 6 x 10(20) cm(-2)) or power-law (alpha sim ilar to 1.7, N-H similar to 10(21) cm(-2)) model. The X-ray light curve sho ws evidence for significant flux evolution between 1996 August and 1998 Jan uary: the count rate from the source decreased by 30 per cent between our 1 996 August and 1997 August ROSAT observations, and the X-ray luminosity mos t likely increased by a factor of similar to2 between our 1997 August ROSAT and 1998 January ASCA observations, although evolution of the spectral sha pe over this interval is not ruled out. The high X-ray luminosity, L-X simi lar to 10(41) erg s(-1), places SN 1995N in a small group of Type IIn super novae with strong circumstellar interaction, and the evolving X-ray luminos ity suggests that the circumstellar medium is distributed inhomogeneously.