G 25.5+0.2 : a very young galactic supernova remnant.
Abstract
Radio emission has been detected from a compact source which satisfies the criteria for a very young galactic supernova remnant. The source, G25.5 + 0.2 has a partially-filled shell structure, a total integrated flux density at 20 cm of 315 mJy, and a flat spectrum between 2 and 20 cm. Observations at 843 and 327 MHz indicate thermal absorption at low frequencies with a turnover in the spectrum near 1 GHz. It is suggested that the lower limit for the age of the supernova remnant is 25 yr, while the upper limit is about 100 yr. It is concluded that G25.5 + 0.2 could be the youngest known supernova remnant in the Galaxy.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 1989
- DOI:
- 10.1093/mnras/241.3.613
- Bibcode:
- 1989MNRAS.241..613C
- Keywords:
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- Extragalactic Radio Sources;
- H Alpha Line;
- Radio Emission;
- Supernova Remnants;
- Very Large Array (Vla);
- Astronomical Catalogs;
- Flux Density;
- H Ii Regions;
- Nonthermal Radiation;
- Astrophysics