SDSSCXOQSO - Sloan Digital Sky Survey Quasars Detected by Chandra
Much more information on the SDSS is available at the project's web site at http://www.sdss.org/.
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 (2009)> =2009ApJ...690..644G
The SDSS object identifier.
The Right Ascension of the SDSS object in the selected equinox. This was given in J2000.0 equatorial decimal degree coordinates to a precision of 10 microdegree (0.036") in the original reference.
The Declination of the SDSS object in the selected equinox. This was given in J2000.0 equatorial decimal degree coordinates to a precision of 1 microdegree (0.0036") in the original reference.
The Galactic Longitude of the SDSS object.
The Galactic Latitude of the SDSS object.
The SDSS asinh i-band PSF magnitude of the object (dereddened).
The photometric redshift of the object: see Weinstein et al. (2004, ApJS, 155, 243).
The photometric redshift range probability.
The photometric redshift lower limit.
The photometric redshift upper limit.
The best redshift of the object: the value quoted is spectroscopic if the value is different from the value of phot_redshift.
A reference code for the source of the spectroscopic redshift: 'S' if from the SDSS Data Release 6 (DR6), 'O' if from ChaMP, and 'R' if a published reference from NED.
The standard ChaMP X-ray source designation, using the 'CXOMP J' prefix for Chandra X-Ray Observatory Multiwavelength Project X-ray sources and the truncated J2000.0 coordinates of the source, e.g., HHMMSS.s+DDMMSS.
The ChaMP internal X-ray source name, in the format 'XSoooooBc_nnn', where oooo = Chandra obsid, c = ACIS CCD ID, and nnn = source number on that CCD.
The Chandra off-axis angle of the X-ray counterpart to the SDSS object, in arcminutes.
The net Chandra counts of the X-ray counterpart to the SDSS object, in the 0.3 - 8 keV range.
The RMS uncertainty in the net Chandra counts.
The vignetting-corrected exposure time for the Chandra counterpart to the SDSS object, in seconds (s).
The Galactic absorbing H I column density, in H atoms cm-2, in the direction of the SDSS object, from Dickey and Lockman (1990, ARAA, 28, 215).
The best-fit intrinsic absorbing H I column density, in H atoms cm-2, inferred from fitting the X-ray spectrum (only given for sources with more than 200 X-ray counts).
The 90% upper error in the best-fit intrinsic absorbing H I column density, in H atoms cm-2.
The 90% lower error in the best-fit intrinsic absorbing H I column density, in H atoms cm-2.
The best-fit power-law (photon energy) index, Gamma, to the Chandra X-ray spectrum. Gamma is the photon number index of an assumed power-law continuum EGamma.
The 90% upper error in the best-fit power-law (photon energy) index, Gamma, to the Chandra X-ray spectrum.
The 90% lower error in the best-fit power-law (photon energy) index, Gamma, to the Chandra X-ray spectrum.
The 0.5 - 8 keV flux of the Chandra counterpart to the SDSS object, in erg/cm2/s.
The logarithm of the monochromatic 2-keV luminosity, L_2keV, of the Chandra counterpart to the SDSS object, in erg/s/Hz.
The logarithm of the monochromatic 2500-Angstrom optical/UV luminosity, log L_2500A, of the Chandra counterpart to the SDSS object, in erg/s/Hz.
The optical/UV to X-ray spectral index, Alpha_ox, of the Chandra counterpart to the SDSS object, defined as the slope of a hypothetical power law from 2500 Angstroms to 2 keV, i.e., 0.3838(log L_2500A - log L_2keV).
The integrated 1.4-GHz (20-cm) flux density of the radio counterpart (FIRST or NVSS) to the SDSS object, in mJy.
This flag parameter is set to 1 to indicate that there is multiple or extended radio morphology of the radio counterpart in FIRST. For such sources, either the lower spatial resolution NVSS flux densities or the summed FIRST flux densities are given.
The radio loudness R of the radio counterpart to the SDSS object, defined as R = 0.4 [imag + 2.5 log(flux_20cm/3.631E06)]. A value of the 20-cm flux density of 1 mJy is assumed as an upper limit where there is no detected FIRST source.
The coded spectral classification of the SDSS object, if avaliable (0 implies no classification). Broad (BAL) and narrow (NAL) absorption lines were identified by visual inspection of the spectra. (A classification of Narrow-Line Seyfert 1 (NLS1) indicates that the spectral measurement of FWHM(Hbeta) gave a value less than 2000 km/s, notice). The non-zero values imply the following:
1 = BAL 2 = NAL 3 = NLS1
This parameter contains a value of 1 if the object was the target of the Chandra observation, i.e., it is not serendipitous.
This parameter contains miscellaneous comments concerning the source.
The HEASARC Browse object classification, based upon the value of the spectral_class parameter.