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J/AJ/128/1483   Optical properties of the CLASXS X-ray sample   (Steffen+, 2004)

An optical catalog of the Chandra Large Area Synoptic X-ray Survey sources. Steffen A.T., Barger A.J., Capak P., Cowie L.L., Mushotzky R.F., Yang Y. <Astron. J., 128, 1483-1500 (2004)> =2004AJ....128.1483S
ADC_Keywords: X-ray sources ; Photometry ; Redshifts Keywords: X-rays: galaxies - X-rays: general Abstract: We present photometric and spectroscopic observations of the X-ray sources detected in the wide-area, moderately deep Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest field. We have B, V, R, I, and z' photometry for 521 (99%) of the 525 sources in the X-ray catalog and spectroscopic redshifts for 271 (52%), including 20 stars. We do not find evidence for redshift groupings of the X-ray sources, like those found in the Chandra Deep Field surveys, because of the larger solid angle covered by this survey. We separate the X-ray sources by optical spectral type and examine the colors, apparent and absolute magnitudes, and redshift distributions for the broad-line and nonbroad-line active galactic nuclei. Combining our wide-area survey with other Chandra and XMM-Newton hard X-ray surveys, we find a definite lack of luminous, high accretion rate sources at z<1, consistent with previous observations that showed that supermassive black hole growth is dominated at low redshifts by sources with low accretion rates. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 119 525 Optical Properties of the CLASXS X-Ray Sample
See also: J/AJ/128/1501 : CLASXS: X-ray catalog (Yang+, 2004) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- CLASXS The Yang et al. (2004, Cat. J/AJ/128/1501) number 5- 14 F10.6 deg RAdeg X-ray right ascension in decimal degrees (J2000) 16- 23 F8.5 deg DEdeg X-ray declination in decimal degrees (J2000) 25- 34 F10.6 deg ORAdeg ? Optical right ascension in decimal degrees (J2000) 36- 43 F8.5 deg ODEdeg ? Optical declination in decimal degrees (J2000) 45- 48 F4.1 arcmin R Smallest aim-point distance 51- 56 F6.3 aW/m2 SB ? The 0.5-2keV X-ray flux (1) 58- 64 F7.3 aW/m2 HB ? The 2-8keV X-ray flux (1) 66- 70 F5.1 mag Bmag ? Aperture-corrected Johnson B-band AB magnitude (2) 72- 73 I2 --- f_Bmag [-1/1]? Limit flag on Bmag (3) 75- 79 F5.1 mag Vmag ? Aperture-corrected Johnson V-band AB magnitude (2) 81- 82 I2 --- f_Vmag [-1/1]? Limit flag on Vmag (3) 84- 88 F5.1 mag Rcmag ? Aperture-corrected Cousins R-band AB magnitude (2) 90- 91 I2 --- f_Rcmag [-1/1]? Limit flag on Rcmag (3) 93- 97 F5.1 mag Icmag ? Aperture-corrected Cousins I-band AB magnitude (2) 99-100 I2 --- f_Icmag [-1/1]? Limit flag on Icmag (3) 102-106 F5.1 mag z'mag ? Aperture-corrected Sloan z'-band AB magnitude (2) 108-109 I2 --- f_z'mag [-1/1]? Limit flag on z'mag (3) 112-116 F5.3 --- zspec ? Spectroscopic redshift 118-119 I2 --- f_zspec ? Flag on zspec (4)
Note (1): From Yang et al. (2004, Cat. J/AJ/128/1501) in units of 10-15ergs/cm2/s. Negative values denote upper limits. Note (2): In the AB magnitude system. An AB magnitude is defined by mAB=-2.5log(fν)-48.60, where fν is the flux of the source in units of ergs/cm2/s/Hz. Note (3): Limit flag on B, V, R, I, and z' magnitudes, defined as follows: 0 = Not a limit; -1 = Lower limit; 1 = Upper limit. Note (4): Flag on zspec, with the following meaning: -2 = Star; -1 = Unobserved; 0 = Absorption-line system; 1 = Star-former; 2 = Seyfert 2 based on strong [O II] relative to Hβ or strong [Ne III] relative to [O II]; 3 = Seyfert 2 with [Ne V] or C IV in emission; 4 = Broad-line AGN (FWHM>1000km/s).
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 17-Feb-2005
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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