J/ApJ/690/644 Properties of SDSS QSOs in the ChaMP (Green+, 2009)
A full year's Chandra exposure on Sloan Digital Sky Survey quasars from the
Chandra multiwavelength project.
Green P.J., Aldcroft T.L., Richards G.T., Barkhouse W.A., Constantin A.,
Haggard D., Karovska M., Kim D.-W., Kim M., Vikhlinin A., Anderson S.F.,
Mossman A., Kashyap V., Myers A.C., Silverman J.D., Wilkes B.J.,
Tananbaum H.
<Astrophys. J., 690, 644-669 (2009)>
=2009ApJ...690..644G 2009ApJ...690..644G
ADC_Keywords: Photometry, SDSS ; QSOs ; X-ray sources ; Surveys ; Redshifts
Keywords: galaxies: active - quasars: absorption lines - quasars: general -
surveys - X-rays: general
Abstract:
We study the spectral energy distributions and evolution of a large
sample of optically selected quasars from the Sloan Digital Sky Survey
that were observed in 323 Chandra images analyzed by the Chandra
Multiwavelength Project. Our highest-confidence matched sample
includes 1135 X-ray detected quasars in the redshift range 0.2<z<5.4,
representing some 36Msec of effective exposure. We provide catalogs of
QSO properties, and describe our novel method of calculating X-ray
flux upper limits and effective sky coverage. Spectroscopic redshifts
are available for about 1/3 of the detected sample; elsewhere,
redshifts are estimated photometrically. We detect 56 QSOs with
redshift z>3, substantially expanding the known sample. We find no
evidence for evolution out to z∼5 for either the X-ray photon index
Γ or for the ratio of optical/UV to X-ray flux αox.
Description:
The ChaMP (Kim et al., 2007, Cat. J/ApJS/169/401) is a wide-area
serendipitous X-ray survey based on archival X-ray images of the
(|b|<20deg) sky observed with the AXAF CCD Imaging Spectrometer (ACIS)
onboard Chandra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 272 1135 Properties of SDSS quasars detected by Chandra
table3.dat 162 347 Properties of SDSS quasars with Chandra limits
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See also:
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/ApJS/150/19 : ChaMP. I. First X-ray source catalog (Kim+, 2004)
J/ApJS/155/73 : Photometric redshifts of X-ray sources in CDF-S (Zheng+, 2004)
J/A+A/434/475 : Redshifts for X-ray selected AGNs (Kitsionas+, 2005)
J/ApJ/618/123 : Hard X-ray-emitting AGNs (Silverman+, 2005)
J/ApJS/169/401 : ChaMP X-ray point source catalog (Kim+, 2007)
J/AJ/133/313 : AGN from RASS and SDSS DR5 (Anderson+, 2007)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- ObjID SDSS-DR6 ObjID
20- 28 F9.5 deg RAdeg SDSS source right ascension (J2000)
30- 38 F9.6 deg DEdeg SDSS source declination (J2000)
40- 45 F6.3 mag imag SDSS i band PSF magnitude (dereddened)
47- 51 F5.3 --- zph Photometric redshift
53- 57 F5.3 --- pr(zph) [0,1] Photometric redshift probability
59- 63 F5.3 --- zph0 Photometric redshift lower limit
65- 69 F5.3 --- zph1 Photometric redshift upper limit
71- 76 F6.4 --- zbest Best redshift
78 A1 --- r_zbest ? Reference if spectroscopic redshift (G1)
80- 95 A16 --- CXOMP ChaMP X-ray source name (JHHMMSS.s+DDMMSS)
97-109 A13 --- ChaMPid Internal ChaMP source ID (2)
111-114 F4.1 arcmin OAA Chandra off-axis angle
116-121 F6.1 ct Xct Net counts in the 0.3-8keV range
123-126 F4.1 --- e_Xct RMS uncertainty on Xct
128-132 F5.1 ks Exp Vignetting-corrected exposure time
134-137 F4.1 10+20cm-2 nHgal Galactic absorbing HI column density
139-142 F4.2 10+22cm-2 nHintr ? Best fit intrinsic absorbing HI column
density
144-147 F4.2 10+22cm-2 nHup ? 90% upper error limit on nHintr
149-153 F5.2 10+22cm-2 nHlo ? 90% lower error limit on nHintr
155-159 F5.2 --- Gam X-ray photon energy index Γ
161-164 F4.2 --- Gam.up 90% lower error limit on Γ
166-171 F6.2 --- Gam.lo 90% lower error limit on Γ
173-179 F7.3 [mW/m2] Fxb 0.5-8keV flux in erg/cm2/s (log10)
181-186 F6.3 [10-7W] logLx 2keV luminosity in erg/s (log10)
188-193 F6.3 [10-7W] logL2500 2500Å luminosity in erg/s (log10)
195-199 F5.3 --- aox Optical/X-ray Spectral index (G3)
201-207 F7.2 mJy F20cm ? 1.4GHz FIRST radio flux density (3)
209 I1 --- n_F20cm [0/1] 1 if multiple/extended radio morphology
211-215 F5.2 mag RL Radio loudness (G4)
217 I1 --- Cl [0/3] Spectral classification (G5)
219 I1 --- Target [0/1] is source a Chandra PI target?
221-272 A52 --- Comm Comments
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Note (2): ChaMP internal X-ray source name, in format XSoooooBc_nnn
where oooo = Chandra obsid, c = ACIS CCD ID, and
nnn = source number on that CCD.
Note (3): Summed flux from multiple FIRST sources or NVSS.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- ObjID SDSS-DR6 ObjID
20- 28 F9.5 deg RAdeg SDSS source right ascension (J2000)
30- 38 F9.6 deg DEdeg SDSS source declination (J2000)
40- 45 F6.3 mag imag SDSS i band PSF magnitude (dereddened)
47- 51 F5.3 --- zph Photometric redshift
53- 57 F5.3 --- pr(zph) Photometric redshift probability
59- 63 F5.3 --- zph0 Photometric redshift lower limit
65- 69 F5.3 --- zph1 Photometric redshift upper limit
71- 76 F6.4 --- zbest Best redshift (G1)
78 A1 --- r_zbest [S ] Reference if spectroscopic redshift (G1)
80- 83 I4 --- ObsID Chandra observation ID
85 I1 --- ccdid ACIS CCD ID
87- 90 F4.1 arcmin OAA Chandra off-axis angle
92- 95 F4.1 ct Xlim 90% Counts upper limit the 0.3-8keV range (1)
97-101 F5.1 ks Exp Vignetting-corrected exposure time
103-106 F4.1 10+20cm-2 nHgal Galactic absorbing HI column density (G2)
108-114 F7.3 [mW/m2] Fxb Upper limit 0.5-8keV flux in erg/cm2/s (log10)
116-121 F6.3 [10-7W] logLx upper limit 2keV luminosity in erg/s (log10)
123-128 F6.3 [10-7W] logL2500 2500Å luminosity in erg/s (log10)
130-134 F5.3 --- aox Lower limit to optical/X spectral index (G3)
136-139 F4.2 mJy F20cm ? 1.4GHz integrated flux density from FIRST
141-144 F4.2 mag RL Radio loudness (G4)
146 I1 --- Cl [0,3] Spectral classification (G5)
148-162 A15 --- Comm Comments
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Note (1): Number of (0.3-8keV) counts that would be detected 90% of the
time at this OAA and exposure on this CCD.
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Global Notes:
Note (G1): If zbest is different than zphot, it is a spectroscopic redshift.
References are:
S = SDSS DR6 spectrum and redshift
O = ChaMP spectrum and redshift
R = redshift/class from NED reference
Note (G2): from Dickey & Lockman, 1990ARA&A..28..215D 1990ARA&A..28..215D
Note (G3): αox=0.3838+log(L2500/Lx).
See section 6 for further details.
Note (G4): RL=0.4(imag-m20cm), where
* m20cm is the radio AB magnitude, m20cm=-2.5log(F20cm/3631Jy)
calculated from the integrated radio flux density. A value of 1mJy
is assumed as an upper limit where there is no detected FIRST source.
* imag is the SDSS i-band magnitude, corrected for Galactic extinction.
Note (G5): Classification as follows:
1 = BAL (Broad absorption lines) identified by visual inspection of
spectra, if available;
2 = NAL (Narrow absorption lines) identified by visual inspection of
spectra, if available;
3 = NLS1: spectral measurement of FWHM(Hβ)<2000km/s.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 02-Feb-2011