Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-10-26
Astronomy and Astrophysics
Astrophysics
20 pages, 10 figures - some of which have been reduced in quality / size. Accepted for publication in the Astronomical Journal
Scientific paper
10.1086/499303
We have combined a sample of 44984 quasars, selected from the Sloan Digital Sky Survey (SDSS) Data Release 3, with the FIRST radio survey. Using a novel technique where the optical quasar position is matched to the complete radio environment within 450", we are able to characterize the radio morphological make-up of what is essentially an optically selected quasar sample, regardless of whether the quasar (nucleus) itself has been detected in the radio. About 10% of the quasar population have radio cores brighter than 0.75 mJy at 1.4 GHz, and 1.7% have double lobed FR2-like radio morphologies. About 75% of the FR2 sources have a radio core (> 0.75 mJy). A significant fraction (~40%) of the FR2 quasars are bent by more than 10 degrees, indicating either interactions of the radio plasma with the ICM or IGM. We found no evidence for correlations with redshift among our FR2 quasars: radio lobe flux densities and radio source diameters of the quasars have similar distributions at low (mean 0.77) and high (mean 2.09) redshifts. Using a smaller high reliability FR2 sample of 422 quasars and two comparison samples of radio-quiet and non-FR2 radio-loud quasars, matched in their redshift distributions, we constructed composite optical spectra from the SDSS spectroscopic data. Based on these spectra we can conclude that the FR2 quasars have stronger high-ionization emission lines compared to both the radio quiet and non-FR2 radio loud sources. This is consistent with the notion that the emission lines are brightened by ongoing shock ionization of ambient gas in the quasar host as the radio source expands.
Becker Robert H.
de Vries Willem H.
White Richard L.
No associations
LandOfFree
Double Lobed Radio Quasars from the Sloan Digital Sky Survey 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 Double Lobed Radio Quasars from the Sloan Digital Sky Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Double Lobed Radio Quasars from the Sloan Digital Sky Survey will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-554873