Evidence for X-ray emission from the type IC supernova 1994I
Abstract
X-ray observations of the galaxy NGC 5194 (M 51) with the High Resolution Imager (HRI) onboard ROSAT were analysed to search for X-ray emission from the type Ic supernova 1994I. An X-ray source with a (0.1-2.4 keV) luminosity of 1.6 x 10(38) erg s(-1) is found at the position of SN 1994I, 79-85 days after the explosion. We believe this to be the first detection of X-ray emission from a type I SN. Assuming the emission arises from shocked circumstellar gas, deposited by the progenitor through non-conservative mass-transfer to a companion, we estimate a constant gas density of rho = 2 x 10(5} cm({-3} v_{16 500}^{2/3)) and a total mass of X-ray luminous gas of M = 1 x 10(-3) M_⊙ inside a sphere of radius 1.2 x 10(16) cm. If the emission arises from the shocked stellar wind of the progenitor, heated by the outgoing wave, we derive a mass-loss rate prior to the outburst of dot {M} = 3.6 x 10(-6} M_{sun ) yr(-1) , similar to mass-loss rates of other type I SNe, inferred from radio observations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1998
- Bibcode:
- 1998A&A...336L...1I
- Keywords:
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- SUPERNOVAE: GENERAL;
- SUPERNOVAE: INDIVIDUAL: SN 1994I;
- GALAXIES: INDIVIDUAL: NGC 5194 (M 51);
- X-RAYS: GALAXIES;
- X-RAYS: GENERAL