Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars

Details Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars

2012-03-20

arxiv.org/abs/1203.4509v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Accepted by A&A

Scientific paper

The origin of broad-absorption-line quasars (BAL QSOs) is still an open issue. Accounting for ~20% of the QSO population, these objects present broad absorption lines in their optical spectra generated from outflows with velocities up to 0.2c. In this work we present the results of a multi-frequency study of a well-defined radio-loud BAL QSO sample, and a comparison sample of radio-loud non-BAL QSOs, both selected from the Sloan Digital Sky Survey (SDSS). We aim to test which of the currently-popular models for the BAL phenomenon - `orientation' or 'evolutionary' - best accounts for the radio properties of BAL quasars. Observations from 1.4 to 43 GHz have been obtained with the VLA and Effelsberg telescopes, and data from 74 to 408 MHz have been compiled from the literature. The fractions of candidate GHz-peaked sources are similar in the two samples (36\pm12% vs 23\pm8%), suggesting that BAL QSOs are not generally younger than non-BAL QSOs. BAL and non-BAL QSOs show a large range of spectral indices, consistent with a broad range of orientations. There is weak evidence (91% confidence) that the spectral indices of the BAL QSOs are steeper than those of non-BAL QSOs, mildly favouring edge-on orientations. At a higher level of significance (\geq97%), the spectra of BAL QSOs are not flatter than those of non-BAL QSOs, which suggests that a polar orientation is not preferred.

Affiliated with

Also associated with

No associations

Rating

Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars 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 Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-496547