J/ApJ/819/154 SDSS-DR7 QSOs with X-ray and UV luminosities (Lusso+, 2016)
The tight relation between X-ray and ultraviolet luminosity of quasars.
Lusso E., Risaliti G.
<Astrophys. J., 819, 154 (2016)>
=2016ApJ...819..154L 2016ApJ...819..154L (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Redshifts ; X-ray sources ; Ultraviolet ; Surveys
Keywords: galaxies: active; galaxies: evolution; methods: statistical;
quasars: general
Abstract:
The observed relation between the soft X-ray and the
optical-ultraviolet emission in active galactic nuclei (AGNs) is
nonlinear and it is usually parametrized as a dependence between the
logarithm of the monochromatic luminosity at 2500Å and at 2keV.
Previous investigations have found that the dispersion of this
relation is rather high (∼0.35-0.4 in log units), which may be caused
by measurement uncertainties, variability, and intrinsic dispersion
due to differences in the AGN physical properties (e.g., different
accretion modes). We show that, once optically selected quasars with
homogeneous SED and X-ray detection are selected, and dust reddened
and/or gas obscured objects are not included, the measured dispersion
drops to significantly lower values (i.e., ∼0.21-0.24dex). We show
that the residual dispersion is due to some extent to variability, and
to remaining measurement uncertainties. Therefore, the real physical
intrinsic dispersion should be <0.21dex. Such a tight relation, valid
over four decades in luminosity, must be the manifestation of an
intrinsic (and universal) physical relation between the disk, emitting
the primary radiation, and the hot electron corona emitting X-rays.
Description:
Our sample starts with the catalog of quasar properties presented by
Shen et al. (2011, J/ApJS/194/45), which contains 105783
spectroscopically confirmed broad-lined quasars. The SDSS quasar
sample is cross-matched with the source catalog 3XMM-DR5 (Rosen et al.
2016A&A...590A...1R 2016A&A...590A...1R, see IX/46). 3XMM-DR5 is the third generation
catalog of serendipitous X-ray sources available online and contains
396910 unique X-ray sources made public on or before 2013 December 31.
The net sky area covered (taking into account overlaps between
observations) is ∼877deg2, for a net exposure time ≥1ks.
For the matching we have adopted a maximum separation of 3 arcsec.
This yields 4069 XMM observations; see section 2 for further
explanations.
We extracted simultaneous data from the latest release of XMM-Newton
Optical Monitor Serendipitous UV Source Survey catalog (Page et al.
2012MNRAS.426..903P 2012MNRAS.426..903P, XMMSUSS2.1) available online. XMMSUSS2.1 includes
all data to the end of 2013 and contains 7170 observations for a total
number of entries of 6246432 (4329363 unique sources) detected in one
to six broad-band UV and optical filters in the Optical Monitor
(XMM-OM) on board the XMM-Newton observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 138 2153 Optical and X-ray properties of the main X-ray
detected quasar sample
table2.dat 100 532 Optical and X-ray properties of the main X-ray
censored quasar sample
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See also:
IX/46 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR5 (XMM-SSC, 2016)
VII/270 : SDSS quasar catalog: tenth data release (Paris+, 2014)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/PAZh/42/313 : 3XMM-DR4 QSO candidates at 3<z<5.5 (Khorunzhev+, 2016)
J/ApJ/815/33 : A Hubble diagram for quasars (Risaliti+, 2015)
J/ApJS/201/10 : SDSS quasar catalog with Swift observations (Wu+, 2012)
J/ApJ/746/54 : Chandra X-ray observations of SDSS-DR5 QSOs (Gibson+, 2012)
J/ApJ/726/20 : X-ray emission from quasars (Miller+, 2011)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/A+A/519/A17 : X-ray/UV ratio of 2XMM AGN (Vagnetti+, 2010)
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/A+A/512/A34 : XMM-COSMOS Type 1 AGNs (Lusso+, 2010)
J/ApJS/183/17 : The SDSS DR5/XMM-Newton quasar survey (Young+, 2009)
J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)
J/A+A/493/339 : XMM-Newton serendipitous Survey. V. (Watson+, 2009)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/AJ/130/387 : SDSS-ROSAT AGN data (Strateva+, 2005)
J/ApJS/92/53 : Einstein database of quasars. I. (Wilkes+, 1994)
http://xmmssc.irap.omp.eu/Catalogue/3XMM-DR5/3XMM_DR5.html : 3XMM-DR5 home page
http://heasarc.gsfc.nasa.gov/W3Browse/all/xmmomsuss.html : XMM-OM SUSS catalog
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS Quasar Name, SDSS identifier
(HHMMSS.ss+DDMMSS.s; J2000)
20- 29 F10.6 deg RAdeg Right Ascension (J2000)
31- 40 F10.6 deg DEdeg Declination (J2000)
42- 49 F8.6 --- z [0.06/5] Spectroscopic redshifts,
SDSS-DR7 quasar catalogue (G1)
51- 57 F7.4 [10-7W/Hz] lgLUV [27.7/32.5] Monochromatic UV luminosity
at 2500Å, in erg/s/Hz units (G2)
59- 65 F7.4 [10-7W/Hz] lgL2 [23.5/28.1] Monochromatic luminosity
at 2keV, in erg/s/Hz units (G3)
67- 75 F9.7 [10-7W/Hz] e_lgL2 [0.01/0.7] Uncertainty in lgL2
77- 91 I15 --- Source Unique X-ray detection ID in
the 3XMM-DR5 catalog (1)
93-104 F12.8 --- gamma1 [-2/2.7]?=-99 Optical (0.3-1um) SED
power-law fit slope
106-117 F12.8 --- gamma2 [-7/2.5]?=-99 UV (1450-3000Å) SED
power-law fit slope
119-128 F10.7 --- gammaX [-1.8/4.5] X-ray index from the slope of
the (XMM 1-5keV) luminosities (2)
130-138 F9.5 --- S/N [2/399] X-ray signal-to-noise (3)
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Note (1): In order to retrieve the 3XMM-DR5 source in Cat. IX/46, the first
digit "1" must be replaced by "2"; note added by CDS.
Note (2): X-ray photon index of the 1st XMM longest exposure estimated from
the slope between the luminosities at 1 and 5keV. The gammaX values
have been used to computed lgL2 and to select the clean quasar sample.
Note (3): X-ray signal-to-noise of the 1st XMM longest exposure:
S/N=EP 8 CTS/EP 8 CTS ERR.
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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- 18 A18 --- SDSS Quasar Name, SDSS identifier
(HHMMSS.ss+DDMMSS.s; J2000)
20- 28 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
30- 39 F10.6 deg DEdeg Declination in decimal degrees (J2000)
41- 48 F8.6 --- z [0.2/4.8] Spectroscopic redshifts,
SDSS-DR7 quasar catalogue (G1)
50- 56 F7.4 [10-7W/Hz] lgLUV [28.5/32] Monochromatic UV luminosity
at 2500Å, in erg/s/Hz (G2)
58- 64 F7.4 [10-7W/Hz] lgL2 [24.5/28.6] Monochromatic luminosity
at 2keV, in erg/s/Hz (G3)
66- 74 F9.7 [10-7W/Hz] e_lgL2 [0.05/0.2] Uncertainty in lgL2
76- 87 F12.8 --- gamma1 [-1.7/2.4]?=-99 Optical (0.3-1um) SED
power-law fit slope
89-100 F12.9 --- gamma2 [-3.3/1.8] UV (1450-3000Å) SED
power-law fit slope
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Global notes:
Note (G1): Spectroscopic redshifts from the SDSS-DR7 quasar catalogue (Z_HW,
the improved redshifts from Hewett & Wild (2010, J/MNRAS/405/2302)).
Note (G2): Luminosities from the SDSS-DR7 quasar catalog.
Note (G3): Luminosities of the 1st XMM longest exposure.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-May-2016