J/AJ/126/2209 X-ray AGN from RASS and SDSS (Anderson+, 2003)
A large, uniform sample of X-Ray-Emitting AGNs: selection approach and an
initial catalog from the ROSAT All-Sky and Sloan Digital Sky Surveys.
Anderson S.F., Voges W., Margon B., Trumper J., Agueros M.A., Boller T.,
Collinge M.J., Homer L., Stinson G., Strauss M.A., Annis J., Gomez P.,
Hall P.B., Nichol R.C., Richards G.T., Schneider D.P., Vanden Berk D.E.,
Fan X., Ivezic Z., Munn J.A., Newberg H.J., Richmond M.W., Weinberg D.H.,
Yanny B., Bahcall N.A., Brinkmann J., Fukugita M., York D.G.
<Astron. J., 126, 2209-2229 (2003)>
=2003AJ....126.2209A 2003AJ....126.2209A
ADC_Keywords: X-ray sources ; QSOs ; Active gal. nuclei ; Surveys ;
Photometry, SDSS
Keywords: catalogs - quasars: general - surveys - X-rays
Abstract:
We describe the initial results of a new program aimed to ultimately
yield ∼104 fully characterized X-ray source identifications - a
sample about an order of magnitude larger than earlier efforts. The
technique is detailed and employs X-ray data from the ROSAT All-Sky
Survey (RASS, Cat. IX/10, IX/29) and optical imaging and
spectroscopic follow-up from the Sloan Digital Sky Survey (SDSS,
J/AJ/123/567); these two surveys prove to be serendipitously very
well matched in sensitivity. As part of the SDSS software pipelines,
optical objects in the SDSS photometric catalogs are automatically
positionally cross-correlated with RASS X-ray sources. Then priorities
for follow-on SDSS optical spectra of candidate counterparts are
automatically assigned using an algorithm based on the known ratios of
fX/fopt for various classes of X-ray emitters at typical RASS fluxes
of 10-13ergs/cm2/s. SDSS photometric parameters for optical
morphology, magnitude, and colors, plus FIRST radio information, serve
as proxies for object class.
Description:
We present initial results toward the ultimate goal of a sample of
∼104 well-characterized optical identifications of RASS X-ray
sources. The emphasis in this installment of the RASS/SDSS catalog is
on our initial set of more than 1200 X-ray-emitting quasars and other
sorts of AGNs.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 107 964 Observed Parameters of Broad-Line RASS/SDSS AGN
table2.dat 111 964 Derived Parameters of Broad-Line RASS/SDSS AGN
table3.dat 107 216 Observed Parameters of Broad-Line RASS/SDSS AGN
Having Narrower Permitted Emission
table4.dat 111 216 Derived Parameters of RASS/SDSS AGN Having
Narrower Permitted Emission
table5.dat 107 45 Observed Parameters of RASS/SDSS BL Lac Candidates
table6.dat 107 45 Derived Parameters of RASS/SDSS BL Lac Candidates
--------------------------------------------------------------------------------
See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)
J/AJ/123/567 : SDSS quasar catalog, I: Early Data Release (Schneider+, 2002)
J/ApJ/596/437 : Stellar-mass black holes in the SDSS (Chisholm+, 2003)
Byte-by-byte Description of file: table1.dat table3.dat table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- RASS RASS X-ray source name (1)
17- 34 A18 --- SDSS SDSS optical counterpart name (1)
36- 40 F5.2 mag u*mag The SDSS u* band PSF magnitude
42- 46 F5.2 mag g*mag The SDSS g* band PSF magnitude
48- 52 F5.2 mag r*mag The SDSS r* band PSF magnitude
54- 58 F5.2 mag i*mag The SDSS i* band PSF magnitude
60- 64 F5.2 mag z*mag The SDSS z* band PSF magnitude
66 I1 --- OType Optical morphology (2)
68- 72 F5.3 --- z ? Redshift from the SDSS spectra
74- 79 F6.4 ct/s CRate RASS 0.1-2.4keV count rate
81- 84 I4 s Exp RASS exposure time
86- 90 F5.2 --- HR1 RASS hardness ratio 1 (3)
92- 96 F5.2 --- HR2 RASS hardness ratio 2 (4)
98-101 I4 --- Detect Source detection likelihood
103-107 F5.2 10-16W/m2 FX RASS absorbed 0.1-2.4keV flux
in units of 10-13erg/s/cm2
--------------------------------------------------------------------------------
Note (1): And position (J2000) using RA/DE nomenclature.
Note (2): See Stoughton et al. (2002AJ....123..485S 2002AJ....123..485S) for more details.
3 = extended/resolved (i.e., galaxy) morphology;
6 = stellar/unresolved morphology.
Note (3): HR1 = (B-A)/(B+A) where
A is the PHA 11-41 channel counts and B is the PHA 52-201 channel counts.
Note (4): HR2 = (D-C)/(D+C) where
C is the PHA 52-90 channel counts and D is the PHA 91-201 channel counts.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat table4.dat table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- RASS RASS X-ray source name (1)
17- 34 A18 --- SDSS SDSS optical counterpart name (1)
36- 40 F5.2 mag g*0mag The SDSS g*0 band PSF magnitude (2)
42- 46 F5.3 --- z ? Redshift from the SDSS spectra
48- 53 F6.2 10-13mW/m2 FXcor RASS absorbed 0.1-2.4keV flux (3)
55- 59 F5.2 [10-7W] logLX ? Log of broadband 0.1-2.4kev X-ray
luminosity in units of erg/s (4)
61- 65 F5.2 [10-7W/Hz] LogL2500 ? Log of monochromatic optical luminosity
at 2500 Angstroms in units of erg/s/Hz (4)
67- 71 F5.2 [10-7W/Hz] LogL2kev ? Log of monochromatic X-ray luminosity
at 2kev in units of erg/s/Hz (4)
73- 76 F4.2 --- alphaox Slope of a hypothetical power law
from 2500Å to 2keV
78-111 A34 --- Com Additional comments
--------------------------------------------------------------------------------
Note (1): And position (J2000) using RA/DE nomenclature.
Note (2): Corrected for extinction according to the reddening maps of
Schlegel, Finkbeiner, & Davis (1998ApJ...500..525S 1998ApJ...500..525S).
Note (3): In units of 10-13erg/s/cm2 and corrected for Galactic absorption
and with absorbing columns estimated from the NH column density
measures of the Stark et al. (1992, Cat. VIII/10) 21cm maps.
Note (4): We adopt values of H0=70km/s/Mpc, ΩM=0.3, and
ΩΛ=0.7 for deriving the luminosities.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 19-Dec-2003