CYDER - Calan-Yale Deep Extragalactic Research Survey X-Ray Source Catalog

Overview

The main goal of the Calan-Yale Deep Extragalactic Research (CYDER) Survey X-ray survey is to study serendipitous X-ray sources detected by Chandra in an intermediate flux range (10^-15 to 10^-12 ergs/s) that comprises most of the X-ray background. A total of 267 X-ray sources spread over five archived fields were detected. The log N - log S distribution obtained for this sample is consistent with the results of other surveys. Deep V and I images were taken of these fields in order to calculate X-ray-to-optical flux ratios. Identifications and redshifts were obtained for 106 sources using optical spectroscopy from 8 m class telescopes to reach the optically faintest sources, to the same level as deeper X-ray fields like the Chandra Deep Fields, showing that the nature of sources detected depends mostly on the optical limit for spectroscopy.

Catalog Bibcode

2005ApJ...621..104T

References

The Calan-Yale Deep Extragalactic Research (CYDER) survey: optical properties
and deep spectroscopy of serendipitous X-ray  sources.
    Treister E., Castander F.J., Maccarone T.J., Gawiser E., Coppi P.S.,
    Urry C.M., Maza J., Herrera D., Gonzalez V., Montoya C., Pineda P.
   <Astrophys. J., 621, 104-122 (2005)>
   =2005ApJ...621..104T

Provenance

This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/621/104, file table4.dat.

Parameters

Name
The name of the X-ray source using the 'CXOCY' prefix followed by the J2000 equatorial coordinates of the X-ray source, as registered with the CDS Dictionary of Nomenclature of Celestial Objects, e.g.,'CXOCY JHHMMSS.s+DDMMSS'.

RA
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the original table.

Dec
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Offset
The offset between the X-ray source and the closest optical counterpart, in arcseconds. Only counterparts with positional offsets of smaller than 2.5 arcseconds are listed here (and were used in the analysis reported in the reference paper).

SB_Counts
The soft-band (0.5 - 2 keV) counts of the X-ray source.

SB_Counts_Error
The uncertainty in the X-ray soft-band counts.

HB_Counts
The hard-band (2.0 - 8 keV) counts of the X-ray source.

HB_Counts_Error
The uncertainty in the X-ray hard-band counts.

Hardness_Ratio
The hardness ratio (HR) is defined as HR=(H-S)/(H-R), where H and S are the counts in the hard (2.0 - 8.0 keV) and soft (0.5 - 2.0 keV) X-ray bands, respectively

Vmag_Limit
This parameter is set to '>' if there was no optical counterpart in the V band within 2.5" of the X-ray source, and the quoted V magnitude is a 5-sigma upper limit.

Vmag
The CTIO V-band magnitude of the closest optical counterpart to the X-ray source that lies within 2.5". Objects in the V-band and I-band images were matched by position, allowing a maximum offset between objects of 1".

Imag_Limit
This parameter is set to '>' if there was no optical counterpart in the I band within 2.5" of the X-ray source, and the quoted I magnitude is a 5-sigma upper limit.

Imag
The CTIO I-band magnitude of the closest optical counterpart to the X-ray source that lies within 2.5". Objects in the V-band and I-band images were matched by position, allowing a maximum offset between objects of 1".

SB_Flux
The soft-band (0.5 - 2 keV) flux of the X-ray source, in erg/s/cm². For sources with 60 or more counts, the X-ray spectra were fit using a power-law model with the appropriate Galactic column density for that direction, while for weaker sources, fits using the same model but for a fixed power law slope of 1.7 were used.

HB_Flux
The hard-band (2 - 8 keV) flux of the X-ray source, in erg/s/cm². For sources with 60 or more counts, the X-ray spectra were fit using a power-law model with the appropriate Galactic column density for that direction, while for weaker sources, fits using the same model but for a fixed power law slope of 1.7 were used.

Redshift
The redshift of the optical counterpart to the X-ray source (only available for sources with spectroscopic identification).

SB_Lx
The soft-band (0.5 - 2 keV) luminosity of the X-ray source, in erg/s, in the observed frame, without accounting for k-corrections or for absorption. Hence, the simple formula, Luminosity = (4 pi x D² x flux), was used.

HB_Lx
The hard-band (2 - 8 keV) luminosity of the X-ray source, in erg/s, in the observed frame, without accounting for k-corrections or for absorption. Hence, the simple formula, Luminosity = (4 pi x D² x flux), was used.

Source_Type
A crude source class, defined as follows:

      X = No spectroscopic identification;
      S = Star;
      G = Galaxy;
      2 = Type 2 AGN;
      Q = Type 1 AGN.

Class
The HEASARC Browse object classification based on the source_type parameter value.

Contact Person

Questions regarding the CYDER database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:26:31 EDT