Radio properties of optically selected quasars

Abstract

view Abstract Citations (96) References (48) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radio Properties of Optically Selected Quasars Hooper, Eric J. ; Impey, Chris D. ; Foltz, Craig B. ; Hewett, Paul C. Abstract Approximately one-quarter (256 objects) of the Large Bright Quasar Survey (LBQS) has been observed with the VLA at 8.4 GHz, resulting in 44 detections (17%) with a median 3 sigma noise limit of 0.29 mJy. Quasars with radio luminosity detectable at this limit are underrepresented at faint absolute blue magnitudes (MB greater than or equal to -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 (8 GHz luminosity greater than 1025 W/Hz) fraction is observed to change as a function of redshift and MB, for MB less than -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 less than or equal to MB less than or equal to -24 and increases at brighter absolute magnitudes. The radio-loud fraction as a function of redshift reaches a local maximum at z approximately equal to 1, and, aside from the effects of increased radio-loud fraction at bright MB, remains roughly constant to redshifts approaching 5. The log R8.4 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. Publication: The Astrophysical Journal Pub Date: May 1995 DOI: 10.1086/175673 Bibcode: 1995ApJ...445...62H Keywords: Luminosity; Quasars; Radiant Flux Density; Radio Observation; Red Shift; Sky Surveys (Astronomy); Visible Spectrum; Brightness Distribution; Data Correlation; Data Reduction; Spectral Energy Distribution; Astronomy; GALAXIES: QUASARS: GENERAL; RADIO CONTINUUM: GALAXIES; SURVEYS full text sources ADS | data products SIMBAD (256) NED (256) CDS (1)