VizieR Online Data Catalog: 6 and 20cm flux densities of radio galaxies (Gurvits+ 1999)
Abstract
We discuss the "angular size-redshift" relation for compact radio sources distributed over a wide range of redshifts 0.011<=z<=4.72. Our study is based on a sample of 330 5 GHz VLBI contour maps taken from the literature. Unlike extended source samples, the "angular size - redshift" relation for compact radio sources appears consistent with the predictions of standard Friedmann world models with q0=~0.5 without the need to consider evolutionary or selection effects due to a "linear size-luminosity" dependence. By confining our analysis to sources having a spectral index, -0.38<=α<=0.18, and a total radio luminosity, Lh2>= 1026W/Hz (H0=100hkm/s/Mpc, q0=0.5 used as a numerical example), we are able to restrict the dispersion in the "angular size-redshift" relation. The best fitting regression analysis in the framework of the Friedmann-Robertson-Walker model gives the value of the deceleration parameter q0=0.21+/-0.30 if there are no evolutionary or selection effects due to a "linear size-luminosity", "linear size-redshift" or "linear size-spectral index" dependence. (2 data files).
- Publication:
-
VizieR Online Data Catalog
- Pub Date:
- November 1998
- DOI:
- 10.26093/cds/vizier.33420378
- Bibcode:
- 1998yCat..33420378G
- Keywords:
-
- Active gal. nuclei;
- QSOs;
- Galaxies: radio;
- Redshifts;
- Radio sources;
- VLBI