The X-Ray Spectrum of Kepler's Supernova Remnant
Abstract
Kepler's SNR was observed with the Large Area Counter on board the Ginga satellite in the energy range 1--12 keV. A strong iron Kalpha emission line has been found at 6.48+/-0.07 keV. This value is too low if the plasma has reached the collisional ionization equilibrium (CIE) condition and, therefore, indicates that the plasma is still in a non-equilibrium ionization (NEI) condition. Using a NEI model, we determined the electron temperature, T_e, to be 4.5+/-0.3 keV, and the plasma parameter, tau (the product of the electron number density n and the elapsed time t after the shock heating), to be 10(10.24+/-0.03) cm(-3) s. We also determined the abundances of heavy elements, and found that iron is overabundant by a factor of 15+/-2 compared to the cosmic value. The iron mass within the remnant was estimated to be about 0.01 MO , which is less than one tenth of that predicted by the theory for Type I SN. We also discuss the differences between Kepler's and Tycho's SNRs.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- April 1990
- Bibcode:
- 1990PASJ...42..279H
- Keywords:
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- Abundance;
- Kepler Laws;
- Supernova Remnants;
- X Ray Spectra;
- Emission Spectra;
- Iron;
- Line Spectra;
- Spaceborne Astronomy;
- Astrophysics;
- ELEMENT ABUNDANCE;
- KEPLER'S SNR;
- SUPERNOVA REMNANTS;
- X-RAY SPECTRA