Flux-Density Relation of Extragalactic Radio Sources
Abstract
We have analyzed the spectral-index distribution of extragalactic radio sources and its variation with flux density and survey frequency. We find that the effect of K-correction on this variation (which if observed could imply that these sources are at cosmological distances) is small compared with bservational uncertainties and other effects. We also derive a form for the intrinsic spectral distribution (assuming it to be independent of redshift and luminosity) which consists of two Gaussians with median spectral indices of 0.8 and 0.4 and with dispersion of 0.25 and 0.4, respectively. The first class of sources is found in low-frequency surveys. The second class, consisting of only a few percent of all sources, appears in high-frequency surveys and has spectraindex distributions similar to sources identified with quasars. Subject headings: quasi-stellar sources or objects radio sources
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1973
- DOI:
- 10.1086/152508
- Bibcode:
- 1973ApJ...186..403P