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CLASXSOID - Chandra Large-Area Synoptic X-Ray Survey Optical & IR Catalog

HEASARC
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Overview

This table contains the redshift catalog for the X-ray sources detected in the Chandra Large Area Synoptic X-ray Survey (CLASXS). The catalog for the CLASXS field includes redshifts from previous work. The authors have extended the redshift information for the full sample using photometric redshifts. The goal of the OPTX Project is to use this survey, together with the Chandra Deep Field-North (CDF-N) and the Chandra Lockman Area North Survey (CLANS), which are among the most spectroscopically complete surveys to date, to analyze the effect of spectral type on the shape and evolution of the X-ray luminosity functions and to compare the optical spectral types with the X-ray spectral properties. The CLANS and CLASXS surveys bridge the gap between the ultradeep pencil-beam surveys, such as the Chandra Deep Fields, and the shallower, very large-area surveys. As a result, they probe the X-ray sources that contribute the bulk of the 2-8 keV X-ray background and cover the flux range of the observed break in the log N - log S distribution.

This table also contains updated optical and infrared photometric catalogs for the X-ray sources in the CLASXS field. Note that for any source with both CFHT and Subaru data in the R and z' bands, the authors used the CFHT magnitude. Typical photometric uncertainties are given in Section 3.6 of the reference paper (Trouille et al. 2008).

The X-ray information for the CLASXS catalog which was published in Yang et al. (2004, AJ, 128, 1501) is available as the HEASARC CLASXS table.


Catalog Bibcode

2008ApJS..179....1T

References

The OPTX Project. I. The Flux and Redshift Catalogs for the CLANS, CLASXS, and
CDF-N Fields.
   Trouille L., Barger A.J., Cowie L.L., Yang Y., Mushotzky R.F.
  <Astrophys. J. Suppl., 179, 1-18 (2008)>
  =2008ApJS..179....1T

Provenance

This table was created by the HEASARC in January 2009 based on the electronic version of Table 12 from the paper which was obtained from the ApJ web site.

HEASARC Implementation

The original ApJS table from which this HEASARC table had 33 objects (out of the original 525 CLASXS X-ray sources) with null positions for the optical/IR counterparts, presumably implying that no counterparts were detected for thee 33 X-ray sources. These entries have been dropped from this HEASARC table, leaving 492 entries.

Parameters

Source_Number
The CLASXS source identification number, a unique identifier in ascending order of J2000 Right Ascension, as used in Yang et al. (2004).

Name
The recommended CLASXS source designation, based on the X-ray source identification number.

RA
The right ascension of the optical/NIR counterpart to the CLASXS X-ray source in the selected equinox. This was given in J2000.0 decimal degrees to an accuracy of 0.001 degrees (3.6 arcsec) in the original table.

Dec
The declination of the optical/NIR counterpart to the CLASXS X-ray source in the selected equinox. This was given in J2000.0 decimal degrees to an accuracy of 0.001 degrees (3.6 arcsec) in the original table.

LII
The Galactic Longitude of the optical/NIR counterpart to the CLASXS X-ray source.

BII
The Galactic Latitude of the optical/NIR counterpart to the CLASXS X-ray source.

Umag
The new and updated, aperture-corrected broadband u (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Bmag
The new and updated, aperture-corrected broadband B (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Gmag
The new and updated, aperture-corrected broadband g' (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Vmag
The new and updated, aperture-corrected broadband V (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Rmag
The new and updated, aperture-corrected broadband R (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Imag
The new and updated, aperture-corrected broadband i' (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Zmag
The new and updated, aperture-corrected broadband z' (AB) magnitude of the optical counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Jmag
The new and updated, aperture-corrected broadband J (AB) magnitude of the near-IR counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Hmag
The new and updated, aperture-corrected broadband H (AB) magnitude of the near-IR counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

Kmag
The new and updated, aperture-corrected broadband K (AB) magnitude of the near-IR counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

IRAC_3p6_um_Mag
The Spitzer IRAC 3.6-um band AB magnitude of the IR counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance).

MIPS_24_um_Mag
The Spitzer MIPS 24-um band AB magnitude of the IR counterpart to the CLASXS X-ray source. A null value for the magnitude means that the source was not detected in this band (2-sigma significance). A value of -1.00 for the 24-um magnitude manes that the position of the X-ray source was not included in the area covered by the IRAC observations.

Redshift
The updated spectroscopic redshift z_spec of the optical/IR counterpart to the CLASXS X-ray source. A value of zspec = 0 and a corresponding value of broad_type = -99 indicates that the source was spectroscopically observed but that neither the redshift nor the class could be identified. A value of zspec = -1 and a corresponding broad_type = -1 indicates that the source was not yet spectroscopically observed. A value of zspec = -2 and a corresponding broad_type = -2 indicates that the source is a star.

Ref_Redshift
This flag parameterr is set to 's' to indicate that the reference for the spectroscopic redshift is Steffen et al. (2004, AJ, 128, 1483). All other spectroscopic redshifts presented in this table come from the reference paper for this table, Trouille et al. (2008), and are presented for the first time.

Phot_Redshift
The photometric redshift z_phot of the optical/IR counterpart to the CLASXS X-ray source obtained using the authors' template-fitting technique. A value of -3 means that the source has a spectroscopic redshift, while a value of -99 that the source has neither a spectroscopic nor a photometric redshift.

Broad_Type
A code for the authors' optical spectral classification of the counterpart to the CLASXS X-ray source. The valid (positive) values of this parameter are 0 for absorbers, 1 for star formers, 3 for high-excitation sources, and 4 for broad-line AGNs. The meaning of the negative values of this parameter is explained above (see the redshift parameter).


Contact Person

Questions regarding the CLASXSOID database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 27-Jan-2009