J/ApJ/445/62 Radio properties of optically selected quasars (Hooper+ 1995)
Radio properties of optically selected quasars.
Hooper E.J., Impey C.D., Foltz C.B., Hewett P.C.
<Astrophys. J. 445, 62 (1995)>
=1995ApJ...445...62H 1995ApJ...445...62H
ADC_Keywords: QSOs ; Redshifts ; Radio sources
Keywords: quasars general - radio continuum: galaxies - surveys
Abstract:
Approximately one-quarter (256 objects) of the Large Bright Quasar
Survey (LBQS, Hewett et al., 1995, Cat. J/AJ/109/1498) has been
observed with the VLA at 8.4GHz, resulting in 44 detections (17%) with
a median 3σ noise limit of 0.29mJy. Quasars with radio
luminosity detectable at this limit are under-represented at faint
absolute blue magnitudes (MB≥-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 >1025W/Hz) fraction is observed to
change as a function of redshift and MB, for MB←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<MB←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 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.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 78 256 Radio and optical observations of LBQS quasars
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- LBQS Source name
12- 16 F5.2 mag Bmag B magnitude
19- 23 F5.3 --- z Redshift
25- 30 F6.2 mag BMag Absolute B magnitude
33- 36 F4.2 mag e_BMag rms uncertainty on BMag
38 A1 --- l_S8.4GHz Limit flag on S8.4GHz
39- 45 F7.2 mJy S8.4GHz Flux density at 8.4GHz
47- 52 F6.3 mJy e_S8.4GHz ? rms uncertainty on S8.4GHz
54 A1 --- l_logLr/Lb Limit flag on logLr/Lb
55- 59 F5.2 --- logLr/Lb Ratio of 8.4GHz luminosity to optical
luminosity averaged over the B passband
61- 64 F4.2 --- e_logLr/Lb ? rms uncertainty on logLr/Lb
68 A1 --- l_logLr Limit flag on logLr
69- 73 F5.2 [W/Hz] logLr Luminosity at 8.4GHz
75- 78 F4.2 [W/Hz] e_logLr ? rms uncertainty on logLr
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History:
* 25-Jul-1997: prepared via OCR at CDS.
* 04-Jun-1988: two OCR errors where corrected, thanks to
H. Andernach
(End) James Marcout, Patricia Bauer [CDS] 25-Jul-1997