Hard X-Rays from the Supernova Remnant IC 443
Abstract
Hard X-rays with energies of up to 20 keV were observed from IC 443 with the X-ray astronomy satellite Ginga. The X-ray flux at energies below 6 keV was found to be consistent with that seen during earlier observations with the Einstein Observatory and HEAO A-2; the X-ray spectrum was observed to be smoothly extended to 20 keV, in which the hard X-ray part could be fitted with a power law of a photon index of about two. The iron line feature was not conspicuous; the equivalent width for the iron emission line was about 0.25 keV. Although an X-ray emission model of IC 443 cannot be uniquely derived from the observations, it is likely that the hard X-rays are emitted from a shock-heated plasma with a temperature higher than 10 keV and a density smaller than 0.1 atoms cm(-3) , which is located in the south-western and western regions of IC 443. This model implies that the age of IC 443 is about one thousand years instead of the previous estimate of 10(4) yr. It is suggested that IC 443 is the remnant of a supernova in AD 837.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- June 1992
- Bibcode:
- 1992PASJ...44..303W
- Keywords:
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- Supernova Remnants;
- X Ray Astronomy;
- Astronomical Models;
- Ginga Satellite;
- Heao 2;
- X Ray Spectra;
- Astrophysics;
- HISTORICAL SUPERNOVA;
- IC 443;
- SUPERNOVA REMNANT;
- X-RAYS