Radio properties of optically selected quasars

DOI

Approximately one-quarter (256 objects) of the Large Bright Quasar Survey (LBQS, Hewett et al., 1995, Cat. ) has been observed with the VLA at 8.4GHz, resulting in 44 detections (17%) with a median 3{sigma} noise limit of 0.29mJy. Quasars with radio luminosity detectable at this limit are under-represented at faint absolute blue magnitudes (M_B_>=-24), an effect which cannot be explained by a potential LBQS selection bias against quasars which have large radio luminosities and small optical luminosities. The radio-loud (8GHz luminosity >10^25^W/Hz) fraction is observed to change as a function of redshift and MB, for M_B_<-24, although the causal variable is ambiguous. The description most consistent with the available data is that radio-loud fraction is approximately constant over the range -27.5<M_B_<-24 and increases at brighter absolute magnitudes. The radio-loud fraction as a function of redshift reaches a local maximum at z~1, and, aside from the effects of increased radio-loud fraction at bright M_B_, remains roughly constant to redshifts approaching 5. The log R_8.4_ distribution (radio-to-optical luminosity ratio) of the current LBQS sample may be bimodal, but the results of statistical tests are ambiguous, requiring a larger sample size to become definite.

Identifier
DOI http://doi.org/10.26093/cds/vizier.14450062
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/445/62
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/445/62
Related Identifier https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/445/62
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/445/62
Provenance
Creator Hooper E.J.; Impey C.D.; Foltz C.B.; Hewett P.C.
Publisher CDS
Publication Year 1998
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Cosmology; Galactic and extragalactic Astronomy; High Energy Astrophysics; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy