Is there any radio shell around the Crab nebula ?
Abstract
Comparison of 1.38 and 2.08-cm RATAN-600 observations against Velusamy's (1985) 20-cm VLA map indicates that the spectral index alpha holds constant along drift scans across the entire Crab Nebula source. Measurements of wide dynamic range with the high-sensitivity 7.6-cm RATAN-600 radiometer place a new upper limit on the surface brightness of any circumnebular shell of 10 to the -22nd W/sq m sr Hz on 14-60 arcmin scales, contravening the existence of a radio shell around the Crab.
- Publication:
-
Pisma v Astronomicheskii Zhurnal
- Pub Date:
- April 1986
- Bibcode:
- 1986PAZh...12..198T
- Keywords:
-
- Astronomical Spectroscopy;
- Centimeter Waves;
- Crab Nebula;
- Radio Spectra;
- Brightness Distribution;
- Spectral Energy Distribution;
- Supernova Remnants;
- Surface Properties;
- Astrophysics