Faint radio sources with ultra-steep spectra as candidates for distant radio galaxies

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

5

Faint Objects, Galactic Evolution, Radio Galaxies, Radio Spectra, Astronomical Spectroscopy, Radio Astronomy, Radio Sources (Astronomy), Red Shift, Visible Spectrum

Scientific paper

The results of an optical identification program of a sample of 75 faint radio sources with ultrasteep radio spectra selected from Westerbork surveys at 327 MHz and with a median flux of 65 mJy are presented. It is found that the fraction of sources that can be identified down to the limit of the present CCD exposures decreases markedly as the spectrum steepens, from 75 percent for a spectral index of 1.1 to about 50 percent at 1.2, to 45 percent at 1.35, and to about 20 percent for spectral indices of 1.5 and higher. A significant correlation between the spectral index and mean redshift (or radio luminosity) is inferred from this. Because a similar effect was found earlier for radio sources with fluxes that are about 25 times higher, it is concluded that the fundamental correlation is between the redshift and spectral index. It is argued that the present USS sources are at redshifts comparable to those of their 4C counterparts, but that their morphologies and optical spectra may differ.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Faint radio sources with ultra-steep spectra as candidates for distant radio galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Faint radio sources with ultra-steep spectra as candidates for distant radio galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Faint radio sources with ultra-steep spectra as candidates for distant radio galaxies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1724501

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.