ROSAT Observations of the Supernova Remnant W51C
Abstract
We have carried out ROSAT X-ray observations of the W51C supernova remnant (SNR). The SNR appears as an elongated (50' × 38') structure along the east-west direction. In contrast to its shell-type morphology in radio continuum, the SNR has both center-filled and shell-type morphologies in X-ray structure. The boundary of the radio structure matches well with that of the X-ray in the southeast. To the west, the X-ray structure appears to extend beyond the radio continuum shell. High-resolution (40") interferometric 21 cm continuum observation shows a thin shell located within the X-ray structure. The thin shell appears to surround the central X-ray-bright region.
The X-ray spectrum of the SNR becomes systematically harder toward the west. By comparing the spectral hardness with the distribution of molecular gas in this region, we have found that the spectral hardening is due to the selective absorption by intervening interstellar gas. The W51C SNR is considered to be behind the "high-velocity molecular stream" at a mean distance of 5.6 kpc. The average X-ray spectrum of the SNR can be fitted well by the Raymond-Smith thermal model with Te = 3.4 × 106 K. We apply the Sedov and evaporative (White & Long 1991) models to derive the SNR parameters. Both models yield an age of ∼3 × 104 yr and an explosion energy of 3.6 × 1051 ergs, which is larger than the canonical value of a single supernova explosion. We discuss the implications of the large energy requirement and the complex X-ray and radio morphologies.- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1995
- DOI:
- 10.1086/175867
- Bibcode:
- 1995ApJ...447..211K
- Keywords:
-
- ISM: INDIVIDUAL ALPHANUMERIC: W51;
- ISM: SUPERNOVA REMNANTS;
- RADIO CONTINUUM: ISM;
- X-RAYS: ISM