J/ApJ/768/37 Radio emission from SDSS quasars (Condon+, 2013)
Active galactic nucleus and starburst radio emission from optically selected
quasi-stellar objects.
Condon J.J., Kellermann K.I., Kimball A.E., Ivezic Z., Perley R.A.
<Astrophys. J., 768, 37 (2013)>
=2013ApJ...768...37C 2013ApJ...768...37C
ADC_Keywords: Magnitudes, absolute ; QSOs ; Radio continuum
Keywords: galaxies: active; galaxies: starburst; quasars: general;
radio continuum: galaxies
Abstract:
We used the 1.4GHz NVSS to study radio sources in two color-selected
QSO samples: a volume-limited sample of 1313 QSOs defined by Mi←23
in the redshift range 0.2<z<0.45 and a magnitude-limited sample of
2471 QSOs with mr≤18.5 and 1.8<z<2.5. About 10% were detected above
the 2.4mJy NVSS catalog limit and are powered primarily by active
galactic nuclei (AGNs). The space density of the low-redshift QSOs
evolves as ρ∝(1+z)6. In both redshift ranges the
flux-density distributions and luminosity functions of QSOs stronger
than 2.4mJy are power laws, with no features to suggest more than one
kind of radio source. Extrapolating the power laws to lower
luminosities predicts the remaining QSOs should be extremely radio
quiet, but they are not. Most were detected statistically on the NVSS
images with median peak flux densities Sp(mJy/beam)~0.3 and
0.05 in the low- and high-redshift samples, corresponding to spectral
luminosities log [L1.4GHz(W/Hz)]~22.7 and 24.1, respectively.
We suggest that the faint radio sources are powered by star formation
at rates dM/dt∼20M☉/yr in the moderate luminosity (median
<Mi>~-23.4) low-redshift QSOs and dM/dt∼500M☉/yr in the
very luminous (<Mi>~-27.5) high-redshift QSOs. Such luminous
starbursts [<log(LIR/L☉)≳11.2 and 12.6, respectively] are
consistent with "quasar mode" accretion in which cold gas flows fuel
both AGN and starburst.
Description:
The SDSS DR7 QSO catalog (Schneider et al. 2010, VII/260) is complete
to i=19.1mag over a solid angle Ω=2.66sr around the North
Galactic Pole. It contains the small sample of 179 color-selected QSOs
defined by Mi←23 in the narrow redshift range 0.2<z<0.3 studied by
Kimball et al. (2011ApJ...739L..29K 2011ApJ...739L..29K) and the larger sample of 1313
QSOs in the wider redshift range 0.2<z<0.45 discussed here. Note that
these magnitudes were calculated for an H0=71km.s/Mpc ΛCDM
cosmology.
The entire DR7 area is covered by the NVSS, whose source catalog is
complete for statistical purposes above a peak flux density
Sp∼2.4mJy/beam at 1.4GHz. In the redshift range 0.2<z<0.45 the 45"
FWHM (full width between half-maximum points) beam of the NVSS spans
150-250kpc.
We also chose a magnitude-limited sample of all 2471 color-selected
DR7 QSOs brighter than mr=18.5 in the redshift range 1.8<z<2.5. The
NVSS detected radio emission stronger than S=2.4mJy from only 191 (8%)
of them (Table 3).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 163 NVSS-detected QSOs, 0.2<z<0.45
table3.dat 51 191 NVSS-detected QSOs, 1.8<z<2.5
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See also:
VIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/AJ/141/182 : Radio and optical properties of QSOs (Kimball+, 2011)
J/MNRAS/383/1513 : 2MASS, SDSS and FIRST fluxes of QSOs (Labita+, 2008)
J/AJ/128/1002 : SDSS candidate type II quasars. II (Zakamska+, 2004)
J/AJ/127/1959 : 1.4GHz emission of KISS emission-line gal. (Van Duyne+ 2004)
J/AJ/125/2411 : SIRTF First-Look Survey (Condon+, 2003)
J/AJ/108/1163 : Radio structure of Quasars (Kellermann+ 1994)
J/MNRAS/263/425 : Low-z BQS Quasars (Miller+, 1993)
J/ApJ/378/65 : 8.4GHz observations of compact starbursts (Condon+ 1991)
Byte-by-byte Description of file: table[13].dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh SDSS Hour of Right Ascension (J2000)
4- 5 I2 min RAm SDSS Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs SDSS Second of Right Ascension (J2000)
13 A1 --- DE- SDSS Sign of the Declination (J2000)
14- 15 I2 deg DEd SDSS Degree of Declination (J2000)
17- 18 I2 arcmin DEm SDSS Arcminute of Declination (J2000)
20- 23 F4.1 arcsec DEs SDSS Arcsecond of Declination (J2000)
25- 30 F6.4 --- z SDSS-DR7 Redshift
32- 38 F7.3 mag iMag [-30/-23] Absolute i band magnitude
40- 45 F6.1 mJy S1.4 [2.4/3259] NVSS flux density at 1.4 GHz
47- 51 F5.2 [W/Hz] logL1.4 [23.6/28.8] Log 1.4GHz luminosity
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 24-Nov-2014