J/MNRAS/496/245 Lx-Luv-Lradio relation in radio-loud quasars (Zhu+, 2020)
The Lx-Luv-Lradio relation and corona-disc-jet connection in optically
selected radio-loud quasars.
Zhu S.F., Brandt W.N., Luo B., Wu J., Xue Y.Q., Yang G.
<Mon. Not. R. Astron. Soc., 496, 245-268 (2020)>
=2020MNRAS.496..245Z 2020MNRAS.496..245Z (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Black holes ; QSOs ; Redshifts ; Optical ;
Ultraviolet ; X-ray sources ; Radio sources
Keywords: black hole physics - galaxies: jets - galaxies: nuclei -
quasars: general - X-rays: galaxies
Abstract:
Radio-loud quasars (RLQs) are more X-ray luminous than predicted by
the X-ray-optical/UV relation (i.e. Lx∝Luvγ) for
radio-quiet quasars (RQQs). The excess X-ray emission depends on the
radio-loudness parameter (R) and radio spectral slope (αr). We
construct a uniform sample of 729 optically selected RLQs with high
fractions of X-ray detections and αr measurements. We find
that steep-spectrum radio quasars (SSRQs; αr=←0.5) follow a
quantitatively similar Lx∝Luvγ relation as that
for RQQs, suggesting a common coronal origin for the X-ray emission of
both SSRQs and RQQs. However, the corresponding intercept of SSRQs is
larger than that for RQQs and increases with R, suggesting a
connection between the radio jets and the configuration of the
accretion flow. Flat-spectrum radio quasars (FSRQs; αr>-0.5)
are generally more X-ray luminous than SSRQs at given Luv and R,
likely involving more physical processes. The emergent picture is
different from that commonly assumed where the excess X-ray emission
of RLQs is attributed to the jets. We thus perform model selection to
compare critically these different interpretations, which prefers the
coronal scenario with a corona-jet connection. A distinct jet
component is likely important for only a small portion of FSRQs. The
corona-jet, disc-corona, and disc-jet connections of RLQs are likely
driven by independent physical processes. Furthermore, the corona-jet
connection implies that small-scale processes in the vicinity of
supermassive black holes, probably associated with the magnetic
flux/topology instead of black hole spin, are controlling the
radio-loudness of quasars.
Description:
We select new RLQs utilizing the Sloan Digital Sky Survey (SDSS; York
et al. 2000AJ....120.1579Y 2000AJ....120.1579Y). The radio data are from the Faint Images
of the Radio Sky at Twenty-Centimeters (FIRST; Becker, White & Helfand
1995ApJ...450..559B 1995ApJ...450..559B) and the NRAO VLA Sky Survey (NVSS; Condon et al.
1998AJ....115.1693C 1998AJ....115.1693C, Cat. VIII/65). Archival Chandra and XMM-Newton
observations are used to constrain the X-ray luminosities. The newly
selected RLQs are combined with those from Miller et al.
(2011ApJ...726...20M 2011ApJ...726...20M, Cat. J/ApJ/726/20) to form a final sample of 729
optically selected RLQs. Compared with Miller et al.
(2011ApJ...726...20M 2011ApJ...726...20M, Cat. J/ApJ/726/20), both the sample size and
X-ray detection fraction are increased. Furthermore, we double the
numbers of spectroscopic redshifts and radio slopes, the latter of
which affects the X-ray properties of RLQs. Importantly, the number of
logR>3 RLQs with reliable spectroscopic redshifts are significantly
increased (by 70 per cent).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 70 729 Properties of optically selected RLQs utilized
in the paper, in ascending order of RA
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See also:
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16)
(Ahumada+, 2020)
VIII/92 : The FIRST Survey Catalog, Version 2014Dec17 (Helfand+ 2015)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/ApJ/726/20 : X-ray emission from quasars (Miller+, 2011)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name SDSS source designation
(HHMMSS.ss+DDMMSS.s)
20- 24 F5.3 --- z Redshift
26- 30 F5.2 mag imag i-band magnitude
32- 36 F5.2 [10-7W/Hz] logL2500 Logarithm of the rest-frame
monochromatic luminosity at 2500Å
38- 42 F5.2 [10-7W/Hz] logL5GHz Logarithm of the rest-frame
monochromatic luminosity at 5GHz
44- 48 F5.2 [10-7W/Hz] logL2keV Logarithm of the rest-frame
monochromatic luminosity at 2keV
50- 53 F4.2 [-] logR Logarithm of the radio loudness
parameter R (1)
55 I1 --- XFlag [0/1] Indicates if the quasar is
detected in X-rays (0:no, 1:yes)
57 A1 --- sd [0/1] Indicates if the X-ray observation
is labelled serendipitous (2)
59 A1 --- spec [0/1] Indicates if the quasar is
spectroscopically confirmed (3)
61- 65 F5.2 --- alphar ? Radio spectral slope
67- 70 F4.2 --- cD Ratio of the flux of the radio core over
the total radio flux
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Note (1): Miller et al. (2011ApJ...726...20M 2011ApJ...726...20M, Cat. J/ApJ/726/20) use
R*=L5GHz/L2500Å to quantify radio-loudness, which can be
converted to R using logR=logR*-0.123.
Note (2): Flag as follows:
0 = Indicates the quasar was targeted
1 = Indicates the X-ray observation is labelled serendipitous
Note (3): Spectroscopy flag as follows:
0 = The redshift is based on photometric data
1 = The quasar is spectroscopically confirmed
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 27-Jun-2023