VLA radio continuum observations of a new sample of high redshift radio galaxies

Details VLA radio continuum observations of a new sample of high redshift radio galaxies VLA radio continuum observations of a new sample of high redshift radio galaxies

2000-05-25

arxiv.org/abs/astro-ph/0005524v1

Astron.Astrophys.Suppl.Ser.145:121-159,2000

Astronomy and Astrophysics

Astrophysics

Accepted for publication in A&A Supplement

Scientific paper

10.1051/aas:2000104

We present new deep multi-frequency radio-polarimetric images of a sample of high redshift radio galaxies (HzRGs), having redshift between 1.7 and 4.1. The radio data at 4.7 and 8.2 GHz were taken with the Very Large Array in the A configuration and provide a highest angular resolution of 0.2''. Maps of total intensity, radio spectral index, radio polarization and internal magnetic field are presented for each source. The morphology of most objects is that of standard FRII double radio sources, but several contain multiple hot-spots in one or both lobes. Compared to similar samples of HzRGs previously imaged, there is a higher fraction (29%) of compact steep spectrum sources (i.e. sources with a projected linear size less than 20 kpc). Radio cores are identified in about half of the sample and tend to have relatively steep spectra (alpha < -1). Polarization is detected in all but 4 sources, with typical polarization at 8.2 GHz of around 10-20%. The Faraday rotation can be measured in most of the radio galaxies: the observed rotation measure (RM) of 8 radio sources exceeds 100 rad m^{-2} in at least one of the lobes, with large gradients between the two lobes. We find no dependence of Faraday rotation with other properties of the radio sources. If the origin of the Faraday rotation is local to the sources, as we believe, then the intrinsic RM is more than a 1000 rad m^{-2}. Because low redshift radio galaxies residing at the center of clusters usually show extreme RMs, we suggest that the high-z large RM sources also lie in very dense environments. Finally, we find that the fraction of powerful radio galaxies with extreme Faraday rotation increases with redshift, as would be expected if their average environment tends to become denser with decreasing cosmic epoch.

Affiliated with

Also associated with

No associations

Rating

VLA radio continuum observations of a new sample of high redshift 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 VLA radio continuum observations of a new sample of high redshift radio galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and VLA radio continuum observations of a new sample of high redshift radio galaxies will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-200553