X-RAY-EMISSION FROM SUPERNOVAE - A REVIEW OF THE OBSERVATIONS

Supernovae have been expected to be X-ray sources for many years. This paper reviews the observations that have detected or placed upper limits on the emission of X-rays from supernovae. A firm upper limit exists on X-ray emission from type Ia supernovae based upon an observation of SN 1992A (parent galaxy: NGC 1380) made with ROSAT. The type II supernovae detected include SN 1978K (NGC 1313), SN 1980K (NGC 6946), SN 1986J (NGC 891), SN 1987A (large Magellanic cloud), and, most recently, SN 1993J (NGC 3031). These supernovae emit X-rays by at least two different processes. I briefly review the proposed emission mechanisms.