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XMDSVVDS4S - XMM-Newton Medium Deep Survey/VIRMOS VLT Deep Survey 4-Sigma Catalog

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Overview

The XMM-Newton Medium Deep Survey/VIRMOS VLT Deep Survey (XMDS/VVDS) 4-Sigma Catalog contains 286 X-ray sources with their optical identification taken from the XMDS survey (using the XMM-Newton EPIC instrument). It is the first catalog of X-ray sources resulting from the central area of the XMM-LSS (Large-Scale Structure Survey). This first version is limited to sources detected at 4{sigma} at least in one energy band, AND falling in the 1 square degree area covered by the optical photometric VVDS survey, which allowed the authors to provide optical and radio identifications.

HEASARC Comment: Notice that this is a catalog of "reliable (though not spectroscopically confirmed) identifications and of the basic optical and radio characteristics of the X-ray sources", and hence, since some X-ray sources have multiple possible counterparts, there are 364 entries in this table corresponding to the 286 X-ray sources mentioned above.


Catalog Bibcode

2005A&A...439..413C

References

The XMM-LSS survey: The XMDS/VVDS 4{sigma} catalogue.
    Chiappetti L., Tajer M., Trinchieri G., Maccagni D., Maraschi L.,
    Paioro L., Pierre M., Surdej J., Garcet  O., Gosset E., Le Fevre O.,
    Bertin E., McCracken H.J., Mellier Y., Foucaud S., Radovich M., Ripepi V.,
    Arnaboldi M.
    <Astron. Astrophys. 439, 413 (2005)>
    =2005A&A...439..413C        (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in August 2005 based on CDS table J/A+A/439/413/xmds1.dat.

Parameters

Sequence_ID
An internal sequence identifier used by the authors.

Name
The IAU-conforming catalog designation for the X-ray source, built from the recommended 'XMDS' prefix and the uncorrected J2000.0 coordinates as provided by the XMM-Newton Science Analysis System (SAS).

RA
The astrometrically corrected Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 coordinates and to a precision of 0.1 seconds of time in the original table.

Dec
The astrometrically corrected Declination of the X-ray source in the selected equinox. This was given in J2000.0 coordinates and 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.

Soft_Counts
The number of net counts in the B (0.5 - 2 keV) band.

Soft_Counts_Error
The error in the net counts in the 0.5 - 2 keV band.

Hard_Counts
The number of net counts in the CD (2 - 10 keV) band.

Hard_Counts_Error
The error in the net counts in the 2 - 10 keV band.

Soft_Flux
The flux in the 0.5 - 2 keV band, in erg/cm^2/s. Fluxes were computed for a power law spectrum with an index of 1.7 and a column density N_H = 2.61 x 10^20 cm^-2, the average Galactic column density in the XMDS field direction from Dickey and Lockman (1990, ARAA, 28, 215), using conversion factors calculated from response matrices generated consistently with the event selections used in the authors' pipeline.

Hard_Flux
The flux in the 2 - 10 keV band, in erg/cm^2/s. Fluxes were computed for a power law spectrum with an index of 1.7 and a column density N_H = 2.61 x 10^20 cm^-2, the average Galactic column density in the XMDS field direction from Dickey and Lockman (1990, ARAA, 28, 215), using conversion factors calculated from response matrices generated consistently with the event selections used in the authors' pipeline.

Best_Band
The X-ray energy band which has the highest Signal-to-Noise (S/N) ratio is coded as follows:

       A  = 0.3 - 0.5 keV
       B  = 0.5 - 2   keV
       C  =   2 - 4.5 keV
       D  = 4.5 - 10  keV
       CD =   2 - 10  keV
  

Gap_Flag
This flag indicates the reliability of the X-ray flux, due to the fact the source falls on inter-CCD gaps in one or more of the EPIC cameras, or close to the edge (or outside) of the FOV of one EPIC camera and is based on the ratio of the exposure at that point in each camera to the maximum exposure in the FOV also for each camera. The coding is as follows:

      0 = maximum reliability, no problems
      1 = fair reliability, X-ray position could fall near a CCD border or gap
      2 = poor reliability, X-ray position almost surely falls close to CCD border
           or gap)
     -1 indicates the source falls outside of the FOV in at least one camera
        (this does not occur for the present 4-sigma subsample)
  

ID_Rank
The identification rank gives the quality of the identification with the counterpart, and is coded as follows:

        0 = optimal (e.g. only counterpart, or brightest and closest)
        1 = good
        2 = ambiguous (e.g. typically more than one possible counterparts listed)
        4 = blank field (unidentified source)
  

XO_Offset
The angular distance between the X-ray source and its counterpart, in arcseconds, in the following order of preference: the VVDS optical counterpart (if any), the radio counterpart in the VIRMOS1.4GHz catalogue (Bondi et al., 2003, Cat. <J/A+A/403/857>), the radio counterpart in the XMM-LSS 325MHz catalogue (Cohen et al., 2003, Cat. <J/ApJ/591/640>), the catalogued NED object, or the catalogued SIMBAD object. It is blank if there are no counterparts.

Rmag
The R magnitude of the counterpart from the VVDS Catalog. The magnitudes are given when there is a valid measurement in the VVDS Catalog. They may be left blank in case of radio counterparts only, or of (usually very bright) objects present only in external (SIMBAD) catalogs.

Rmag_Error
The error in the R magnitude of the counterpart from the VVDS Catalog.

Imag
The I magnitude of the counterpart from the VVDS Catalog. The magnitudes are given when there is a valid measurement in the VVDS Catalog. They may be left blank in case of radio counterparts only, or of (usually very bright) objects present only in external (SIMBAD) catalogs.

Imag_Error
The error in the I magnitude of the counterpart from the VVDS Catalog.

Photometry_Flag
This flag gives the quality (photometric reliability) of the VVDS photometry, derived from McCracken et al. (2003, A&A, 410, 17), as follows:

       0 = magnitudes flagged as good
       1 = magnitudes flagged as possibly bad, but not saturated
       2 = magnitudes flagged as bad because saturated
  

VIRMOS_Flag
This flag is set to "V" to indicate an association with a radio radio counterpart in the VIRMOS 1.4GHz Catalog (Bondi et al., 2003, Cat. <J/A+A/403/857>), otherwise it is left blank.

XMM_LSS_Flag
This flag is set to "L" to indicate an association with a radio counterpart in the XMM-LSS 325 MHz catalogue (Cohen et al., 2003, Cat. <J/ApJ/591/640>), otherwise it is left blank.

Alt_Name
The name of the counterpart in external sites such as NED, SIMBAD, or the XMM-LSS 325 MHz catalogue (Cohen et al., 2003, Cat. <J/ApJ/591/640>), in this preferred order. Note that the VIRMOS 1.4GHZ catalog (Bondi et al., 2003, Cat. <J/A+A/403/857>) is in SIMBAD.


Contact Person

Questions regarding the XMDSVVDS4S database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 8-Aug-2005