J/ApJ/831/168 6GHz JVLA observations of low-z SDSS quasars (Kellermann+, 2016)
Radio-loud and radio-quiet QSOs.
Kellermann K.I., Condon J.J., Kimball A.E., Perley R.A., Ivezic Z.
<Astrophys. J., 831, 168-168 (2016)>
=2016ApJ...831..168K 2016ApJ...831..168K (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Radio continuum ; Photometry, SDSS ; Redshifts
Keywords: quasars: general
Abstract:
We discuss 6GHz JVLA observations covering a volume-limited sample of
178 low-redshift (0.2<z<0.3) optically selected quasi-stellar objects
(QSOs). Our 176 radio detections fall into two clear categories:
(1) about 20% are radio-loud QSOs (RLQs) with spectral luminosities of
L6≳1023.2W/Hz that are primarily generated in the active galactic
nucleus (AGN) responsible for the excess optical luminosity that
defines a bona fide QSO; and (2) the remaining 80% that are
radio-quiet QSOs (RQQs) that have 1021≲L6≲1023.2W/Hz and radio
sizes ≲10kpc, and we suggest that the bulk of their radio emission is
powered by star formation in their host galaxies. "Radio-silent" QSOs
(L6≲1021W/Hz) are rare, so most RQQ host galaxies form stars
faster than the Milky Way; they are not "red and dead" ellipticals.
Earlier radio observations did not have the luminosity sensitivity of
L6≲1021W/Hz that is needed to distinguish between such RLQs and
RQQs. Strong, generally double-sided radio emission spanning ≫10kpc
was found to be associated with 13 of the 18 RLQ cores with peak flux
densities of Sp>5mJy/beam (log(L)≳24). The radio luminosity
function of optically selected QSOs and the extended radio emission
associated with RLQs are both inconsistent with simple "unified"
models that invoke relativistic beaming from randomly oriented QSOs to
explain the difference between RLQs and RQQs. Some intrinsic property
of the AGNs or their host galaxies must also determine whether or not
a QSO appears radio-loud.
Description:
We have reprocessed the VLA observations of a sample of SDSS QSOs
discussed in Kimball+ (2011ApJ...739L..29K 2011ApJ...739L..29K), and generated a catalog
of radio sources associated with each QSO.
We detected radio emission at 6GHz from all but two of the 178
color-selected SDSS QSOs contained in our volume-limited sample of
QSOs more luminous than M_i=-23 and with redshifts 0.2<z<0.3.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 121 178 Results
images/* . 178 Individual 6GHz VLA images of all 178 SDSS QSOs
--------------------------------------------------------------------------------
See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/MNRAS/455/4191 : Radio emission from radio-quiet quasars (Zakamska+, 2016)
J/ApJ/798/134 : MOJAVE. XII. Acceleration of blazar jets (Homan+, 2015)
J/MNRAS/444/2498 : Radio-Quiet BAL quasars sample (Rochais+, 2014)
J/MNRAS/440/476 : Low-redshift quasars in SDSS Stripe 82 (Falomo+, 2014)
J/MNRAS/436/3759 : ECDFS sources optical/IR counterparts (Bonzini+, 2013)
J/ApJS/205/13 : VLA 1.4GHz survey of ECDF-S (DR2) (Miller+, 2013)
J/ApJ/768/37 : Radio emission from SDSS quasars (Condon+, 2013)
J/MNRAS/421/1569 : Properties of 18286 SDSS radio galaxies (Best+, 2012)
J/AJ/138/1874 : MOJAVE VI. Kinematic analysis of blazar jets (Lister+, 2009)
J/AJ/137/42 : Matched SDSS and FIRST Sample (Rafter+, 2009)
J/ApJS/179/114 : VLA 1.4GHz survey of E-CDF-S (Miller+, 2008)
J/ApJS/179/71 : VLA survey of the CDF-S I. (Kellermann+, 2008)
J/MNRAS/383/1513 : 2MASS, SDSS and FIRST fluxes of QSOs (Labita+, 2008)
J/ApJ/658/815 : Radio loudness of active galactic nuclei (Sikora+, 2007)
J/MNRAS/341/993 : ujbr photometry and redshifts of QSOs (Cirasuolo+, 2003)
J/ApJS/126/133 : The FIRST bright quasar survey. II. (White+, 2000)
J/ApJ/511/612 : Comparison of Radio-loud & Quiet QSOs (Goldschmidt+, 1999)
J/AJ/108/1163 : Radio structure of Quasars (Kellermann+ 1994)
J/MNRAS/263/425 : Low-z BQS Quasars (Miller+, 1993)
J/ApJ/269/352 : Quasar evolution (Schmidt+, 1983)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- SDSS Source name (HHMMSS.SS+DDMMSS.S; J2000)
20- 21 I2 h RAh VLA hour of right ascension (J2000) (1)
23- 24 I2 min RAm VLA minute of right ascension (J2000)
26- 31 F6.3 s RAs VLA second of right ascension (J2000)
33 A1 --- DE- VLA sign of declination (J2000) (1)
34- 35 I2 deg DEd VLA degree of declination (J2000) (1)
37- 38 I2 arcmin DEm VLA arcminute of declination (J2000)
40- 44 F5.2 arcsec DEs VLA arcsecond of declination (J2000)
46- 49 F4.2 arcsec delta [0/8.8] Separation between the radio and
optical positions
51- 55 F5.3 --- z [0.2/0.3] Redshift from the SDSS
57- 64 F8.1 uJy S6 [16/770000] VLA 6GHz Integrated flux density
(µJy)
66- 72 F7.1 uJy e_S6 [4/23103] rms error in S6 (2)
74- 81 F8.1 uJy/beam S6pk [16/322000] 6GHz Peak flux density at 3.5"
resolution (Sp; µJy/beam solid angle)
83- 88 F6.1 uJy/beam e_S6pk [4/9661] rms error in S6pk
90- 94 F5.3 --- Spk/S [0.009/1] Ratio of peak to integrated
flux density
96-100 F5.2 W/Hz logL [21.4/26.2] Log of 6GHz spectral luminosity
102-107 F6.3 mag imag [15.1/17.8] i-band apparent magnitude
from the SDSS catalog
109-114 F6.2 mag IMag [-24.8/-22.5] I-band absolute magnitude
116-121 F6.2 --- Ratio [0.01/523] Ratio of radio (6 GHz) to
optical (i band) flux density (3)
--------------------------------------------------------------------------------
Note (1): Note that SDSS J103421.71+605318.1 does not have a detected
VLA counterpart (value set to 00:00:00.000+00:00:00.00).
Note (2): rms error calculated as the quadratic sum of the statistical error
and a 3% uncertainty in the calibration.
Note (3): Ratio R of radio (6GHz) to optical (i band) flux density calculated
from Si=10(9.56-i/2.5)µJy.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
21-Apr-2017: Insert into VizieR
06-Feb-2018: Main position in VizieR changed for the optical one.
Acknowledgements:
Amy Kimball [National Radio Astronomy Observatory]
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Feb-2017