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XMMCFRSOID - XMM-Newton/Canada-France Redshift Survey Fields Optical Identifications

HEASARC
Archive

Overview

This table contains the proposed identifications for all the good optical ID candidates (true probability value P' that the object is not associated of < 0.15) corresponding to the X-ray sources from the XMM-Newton surveys of the 3 and 14 hours Right Ascension (hereafter 3-h and 14-h, respectively) fields from the Canada-France Redshift Survey. (These fields are also known as the Groth Strip). The X-ray sources cover the 0.5 - 10 keV flux range from ~2 x 10^-15 - 10^-13 erg/cm^2^/s.

The authors have used a subset of the XMM-Newton sources, which have Chandra positions, to determine the best method of obtaining optical identifications of sources with only XMM-Newton positions. They found optical identifications for 79% of the XMM-Newton sources for which there were deep optical images. The sources without optical identifications are likely to be optically fainter and have higher redshifts than the sources with identifications. The authors have estimated 'photometric redshifts' for the identified sources, calibrating their method using ~200 galaxies in the fields with spectroscopic redshifts. They find that the redshift distribution has a strong peak at z ~ 0.7.


Catalog Bibcode

2004MNRAS.350..785W

References

XMM-Newton surveys of the Canada-France Redshift Survey fields -
II. The X-ray catalogues, the properties of the host galaxies and the redshift
distribution.
    Waskett T.J., Eales S.A., Gear W.K., McCracken H.J., Brodwin M., Nandra K.,
    Laird E.S., Lilly S.
   <Mon. Not. R. Astron. Soc., 350, 785-797 (2004)>
   =2004MNRAS.350..785W    (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in July 2005 based on the combination of CDS table J/MNRAS/350/785/tablea34.dat (the merged Tables A3 and A4 from the published paper) and CDS table J/MNRAS/350/785/tablea56.dat (the merged Tables A5 and A6 from the published paper).

HEASARC Implementation

The tabular material containing the X-ray source information for these proposed optical counterparts (the data given in Tables A1 and A2 in the published paper) is presented in the HEASARC Browse table called XMMCFRSCAT, and can be also be accessed for any given optical object by clicking on the link labelled 'X-ray' in the Related Links column on the query results page.

Parameters

Name
The X-ray source designation as recommended by the Dictionary of Nomenclature of Celestial Objects, using the prefix '[WEG2004] 3h ' for the objects from the 3-h field and '[WEG2004] 14h ' for the objects from the 14-h field, and a running number ordered by total number of counts detected in the full X-ray band, with the source with the greatest number being listed first. Due to vignetting, this order is approximately but not exactly the same as the order by X-ray flux.

CFDF_Number
The Canada-France Deep Fields survey (CFDF: McCracken et al. 2001, A&A, 376, 756) Catalog number.

RA
The Right Ascension of the CFDF object in the selected equinox, as measured by the source detection software. This was given in J2000 equatorial coordinates to a precision of 0.00001 degrees in the original table.

Dec
The Declination of the CFDF object in the selected equinox, as measured by the source detection software. This was given in J2000 equatorial coordinates to a precision of 0.00001 degrees in the original table.

LII
The Galactic Longitude of the CFDF object.

BII
The Galactic Latitude of the CFDF object.

XO_Offset
The angular offset between the XMM-Newton source and the CFDF object, in arcseconds.

True_Probability
The true probability value P' that the candidate object is a foreground or background object and not physically related to the XMM-Newton X-ray source, as described in Section 3.1 of the published paper. In all but two cases, the authors chose the CFDF object with the lowest value of P' as the most likely association. In these two exceptional cases, the galaxy with the lowest value of P' was close to 6 arcseconds away from the XMM-Newton position, and the authors preferred the candidate with the slightly higher value of P' but which was much closer to the XMM-Newton position (X-ray sources '[WEG2004] 14h 15' and '[WEG2004] 14h 50').

Redshift
The spectroscopic redshift of the optical object.

Phot_Redshift_1
The photometric redshift of the optical object from UBVI photometry using the Benitez (2000, ApJ, 536, 571) photometric redshift estimation code which uses a Bayesian approach and template-fitting technique, called BPZ. The estimation techniques are discussed in Appendix B of the published paper.

Phot_Redshift_1_Flag
This flag parameter is set to ':' (changed in this HEASARC table from '*' in the published and CDS versions) to indicate that the redshift derived from UBVI photometry is less reliable due to the value of the BPZ in-code statistic P_DeltaZ being less than 0.9.

Phot_Redshift_2
The photometric redshift of the optical object from UBVIK photometry using the Benitez (2000, ApJ, 536, 571) photometric redshift estimation code which uses a Bayesian approach and template-fitting technique, called BPZ. The estimation techniques are discussed in Appendix B of the published paper.

Phot_Redshift_2_Flag
This flag parameter is set to ':' (changed in this HEASARC table from '*' in the published and CDS versions) to indicate that the redshift derived from UBVIK photometry is less reliable due to the value of the BPZ in-code statistic P_DeltaZ being less than 0.9.

Phot_Redshift_3
The photometric redshift of the optical object from UBVRIZ photometry using the estimate given by a code developed specifically for the CFDF (Brodwin et al. 2003, astro-ph/0310038). The extra filters remove some potential redshift degeneracies in certain galaxy templates. The photometric redshift estimation techniques are discussed in Appendix B of the published paper.

Phot_Redshift_3_Flag
This flag parameter is set to ':' (changed in this HEASARC table from '*' in the published and CDS versions) to indicate that the redshift derived from UBVRIZ photometry is less reliable because of multiple likelihood peaks or broad errors.

Notes
Codes for additional notes, as follows:

              -: lies outside Canada-France Deep Fields survey (CFDF) map
              c: lies within Chandra map (X-ray property)
              d: d = detected by Chandra (X-ray property)
              e: extended source (X-ray property)
              q: known QSO
              s: object with a stellar profile
              *: in 3h, sources 7 and 19 are in fact the same source split into
                  two owing to its lying on a PN chip gap
  

Itot_Mag
The total I magnitude in the AB system measured using a variable aperture. This total magnitude is used as the prior in the BPZ photometric redshift code.

Umag
The U magnitude in the AB system measured in a 3 arcsecond diameter aperture. This magnitude and its error are used as part of the input catalog.

Umag_Error
The RMS uncertainty in the U magnitude.

Bmag
The B magnitude in the AB system measured in a 3 arcsecond diameter aperture. This magnitude and its error are used as part of the input catalog.

Bmag_Error
The RMS uncertainty in the B magnitude.

Vmag
The V magnitude in the AB system measured in a 3 arcsecond diameter aperture. This magnitude and its error are used as part of the input catalog.

Vmag_Error
The RMS uncertainty in the V magnitude.

Imag
The I magnitude in the AB system measured in a 3 arcsecond diameter aperture. This magnitude and its error are used as part of the input catalog.

Imag_Error
The RMS uncertainty in the I magnitude.

Kmag
The K magnitude in the AB system measured in a 3 arcsecond diameter aperture. This magnitude and its error are used as part of the input catalog.

Kmag_Error
The RMS uncertainty in the K magnitude.


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 19-Jul-2005