The Host Galaxies of LoBAL QSOs at Low z: A Perspective from HST UVIS Images
Abstract
We present GALFIT models of a complete optically-selected volume-limited sample of Low-Ionization Broad Absorption Line QSOs (LoBALs) in the redshift range 0.5-0.6 observed with HST WFC3 UVIS F475W. We investigate the morphologies in the rest frame u which map the younger stellar populations. In addition, we present statistics on the number of neighborhood galaxies within 150 kpc and possible trends between clustering and host galaxy properties. This sample of LoBALs is selected from QSOs characterized by their extreme blue-shifted absorption in the Mg II line—which is a signature of high velocity winds towards the observer. Only ~1-3% of optically selected QSOs are LoBALs. Their low fraction could be explained by their orientation or by a short period of outflow manifest in all QSOs during their lifetime. We aim to better understand the possibility of the evolutionary model by studying their morphologies in detail. Previous work on this sample, from images with F125W filter (rest frame i), shows that at least 60% of these objects exhibit signs of recent merger activity. We complement those results with our results from the UVIS observations and neighborhood clustering statistics.
- Publication:
-
American Astronomical Society Meeting Abstracts #228
- Pub Date:
- June 2016
- Bibcode:
- 2016AAS...22831408B