57.5 MHz observations of extended nonthermal sources in the galactic plane.
Abstract
The sources that appear in absorption against the nonthermal galactic background in the present radio-continuum maps of two fields in the galactic plane are identified as H II regions. Three extended sources that are observed in emission are classified as SNRs on the basis of derived spectral index values. The objects are G8.7-0.1, which is the extended component of the W30 region, G18.1-0.2, and G19.96-0.18; this last is noted to have a flat radio spectrum and a filled-center morphology, and is suggested to be a Crab-like SNR.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 1986
- DOI:
- 10.1086/114270
- Bibcode:
- 1986AJ.....92.1372O
- Keywords:
-
- Astronomical Spectroscopy;
- Milky Way Galaxy;
- Nonthermal Radiation;
- Pulsars;
- Radio Sources (Astronomy);
- Supernova Remnants;
- Absorption Spectra;
- Astronomical Maps;
- Continuous Spectra;
- Data Reduction;
- Emission Spectra;
- H Ii Regions;
- Radiant Flux Density;
- Astrophysics;
- Galactic Plane:H II Regions;
- Galactic Plane:Radio Sources;
- H II Regions:Galactic Plane;
- Radio Maps:Supernova Remnants;
- Radio Sources:Galactic Plane;
- Supernova Remnants:Discoveries;
- Supernova Remnants:Radio Maps