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XDEEP2 - DEEP2 Galaxy Redshift Survey Fields Chandra Point Source Catalog

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Overview

This table contains the X-ray point-source catalog produced from the Chandra Advanced CCD Imaging Spectrometer (ACIS-I) observations of the combined ~3.2 deg2 DEEP2 (XDEEP2) survey fields, which consist of four ~ 0.7 - 1.1 deg2 fields. The combined total exposures across all four XDEEP2 fields range from ~ 10 ks to 1.1 Ms. The authors detect X-ray point sources in both the individual ACIS-I observations and the overlapping regions in the merged (stacked) images. They find a total of 2976 unique X-ray sources within the survey area with an expected false-source contamination of ~ 30 sources (<~ 1%). In their paper, the authors present the combined log N-log S distribution of sources detected across the XDEEP2 survey fields and find good agreement with the Extended Chandra Deep Field and Chandra-COSMOS fields to f_(X,0.5-2keV)_ ~ 2 x 10-16 erg cm-1 s-1. Given the large survey area of XDEEP2, they additionally place relatively strong constraints on the log N-log S distribution at high fluxes (f_(X,0.5-2keV) ~ 3 x 10-14 erg cm-1 s-1), and find a small systematic offset (a factor ~ 1.5) toward lower source numbers in this regime, when compared to smaller area surveys. The number counts observed in XDEEP2 are in close agreement with those predicted by X-ray background synthesis models. Additionally, the authors present a Bayesian-style method for associating the X-ray sources with optical photometric counterparts in the DEEP2 catalog (complete to RAB < 25.2) and find that 2126 (~ 71.4% +/- 2.8%) of the 2976 X-ray sources presented here have a secure optical counterpart with a <~ 6% contamination fraction. The present table provides the DEEP2 optical source properties (e.g., magnitude, redshift) as part of the X-ray-optical counterpart catalog.

Catalog Bibcode

2012ApJS..202....6G

References

The Chandra X-ray point-source catalog in the DEEP2
Galaxy Redshift Survey fields
    Goulding A.D., Forman W.R., Hickox R.C., Jones C., Kraft R., Murray S.S.,
    Vikhlinin A., Coil A.L., Cooper M.C., Davis M., Newman J.A.
   <Astrophys. J. Suppl., 202, 6 (2012)>
   =2012ApJS..202....6G

Provenance

This table was created by the HEASARC in October 2012 based on electronic versions of Tables 5 and 7 from the reference paper which were obtained from the ApJS web site.

Parameters

Name
The unique DEEP2 source identifier. The HEASARC has added the prefix 'XDEEP2' to the source names as given in the original table and removed the underscore character as well. Thus, the names now have the format of 'XDEEP2 FFF n', where 'FFF' is the sub-field name (for sources in Field 1) or the field name (for sources in Fields 2, 3 and 4), and n is a running source number for each Field 1 sub-field or for each of Fields 2, 3 and 4, e.g., 'XDEEP2 AEG1 1', 'XDEEP2 F4 2', etc. Notice that the names of the 3 AEGIS sub-fields have been abbreviated to 'AEG', e.g., 'AEG1' stands for AEGIS-1.

Field_Subfield_ID
The DEEP2 field and ObsID/sub-field in which the source was detected, e.g., 'F1_AEG1', 'F4_8630', etc. For sources in Field 1, the second part of this parameter following the underscore is the sub-field identifier, whereas for sources in Fields 2, 3 and 4, the second part of this parameter is the Chandra ObsID. Full details of the observations, fields and sub-fields are given in Table 1 of the reference paper.

Csc_Name
The unique source identifier for the matched XDEEP2 source if present in the Chandra Source Catalog, e.g., 'CXO JHHMMSS.s+DDMMSS'.

RA
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 decimal degrees to a precision of 10-5 degrees (0.036 arcseconds) in the original table.

Dec
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 decimal degrees to a precision of 10-5 degrees (0.036 arcseconds) in the original table.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Error_Radius
The X-ray source centroid positional error, in arcseconds. Following Murray et al. (2005, ApJS, 161, 1), the authors estimated the 90% uncertainty on the source locations as Xerr = R50/(sqrt(C50) - 1), where R50 is the 50% encircled energy extraction region radius and C_50 is the number of net counts within this region. For those sources with C50 <= 5 counts, the authors set a minimum centroid error of 0.8 arcseconds (i.e., the 99% positional accuracy on the ACIS-I detector), which takes into account the systematic uncertainties associated with the spacecraft and detector astrometry. Random uncertainties also become negligible for sources with large numbers of counts.

Radius_50pc_EEF
The source extraction aperture radius at 50% of the ACIS-I effective area R50, in arcseconds, given the off-axis distance of the X-ray source.

Radius_90pc_EEF
The source extraction aperture radius at 90% of the ACIS-I effective area R90, in arcseconds, given the off-axis distance of the X-ray source.

Off_Axis
The off-Axis Distance of the X-ray source from the aim-point of the observation in which it was detected, in arcminutes (converted by the HEASARC from the arcseconds units used in the original table).

SB_Counts_50pc_EEF_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

SB_Counts_50pc_EEF
The net soft-band (0.5-2 keV) counts of the X-ray source within the R50 radius aperture.

SB_Counts_50pc_EEF_Error
The uncertainty in the associated parameter value calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

SB_Counts_90pc_EEF_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

SB_Counts_90pc_EEF
The net soft-band (0.5-2 keV) counts of the X-ray source within the R90 radius aperture.

SB_Counts_90pc_EEF_Error
The uncertainty in the associated parameter value calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

HB_Counts_50pc_EEF_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

HB_Counts_50pc_EEF
The net hard-band (2-7 keV) counts of the X-ray source within the R50 radius aperture.

HB_Counts_50pc_EEF_Error
The uncertainty in the associated parameter value calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

HB_Counts_90pc_EEF_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

HB_Counts_90pc_EEF
The net hard-band (2-7 keV) counts of the X-ray source within the R90 radius aperture.

HB_Counts_90pc_EEF_Error
The uncertainty in the associated parameter value calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

FB_Counts_50pc_EEF_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

FB_Counts_50pc_EEF
The net full-band (0.5-7 keV) counts of the X-ray source within the R50 radius aperture.

FB_Counts_50pc_EEF_Error
The uncertainty in the associated parameter value calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

FB_Counts_90pc_EEF_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

FB_Counts_90pc_EEF
The net full-band (0.5-7 keV) counts of the X-ray source within the R90 radius aperture.

FB_Counts_90pc_EEF_Error
The uncertainty in the associated parameter value calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

SB_Flux_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

SB_Flux
The soft-band (0.5-2 keV) flux of the X-ray source, in erg cm-2 s-1. To build a homogeneous X-ray catalog, the authors assumed a single simple absorbed power-law spectrum with slop Gamma = 1.7 (i.e., the typical intrinsic slope of an AGN) for all sources and column densities N_H- = (1.24, 1.75, 3.99 and 2.89) x 1020 cm-2 for the sources in Fields 1 - 4, respectively. The authors used PIMMS to calculate the count-rate-flux conversion factors assuming the simulated ARFs from AO9 of the Chandra program. Total galactic H I column densities were determined using Stark et al. (1992, ApJ, 79, 77).

SB_Flux_Error
The uncertainty in the associated parameter value, in erg cm-2 s-1, calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

HB_Flux_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

HB_Flux
The hard-band (2-7 keV) flux of the X-ray source, in erg cm-2 s-1. To build a homogeneous X-ray catalog, the authors assumed a single simple absorbed power-law spectrum with slop Gamma = 1.7 (i.e., the typical intrinsic slope of an AGN) for all sources and column densities N_H- = (1.24, 1.75, 3.99 and 2.89) x 1020 cm-2 for the sources in Fields 1 - 4, respectively. The authors used PIMMS to calculate the count rate-flux conversion factors assuming the simulated ARFs from AO9 of the Chandra program. . Total galactic H I column densities were determined using Stark et al. (1992, ApJ, 79, 77).

HB_Flux_Error
The uncertainty in the associated parameter value, in erg cm-2 s-1, calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

FB_Flux_Limit
This parameter is set to '<' if the associated parameter is an upper limit rather than an actual value.

FB_Flux
The full-band (0.5-7 keV) flux of the X-ray source, in erg cm-2 s-1. To build a homogeneous X-ray catalog, the authors assumed a single simple absorbed power-law spectrum with slop Gamma = 1.7 (i.e., the typical intrinsic slope of an AGN) for all sources and column densities N_H- = (1.24, 1.75, 3.99 and 2.89) x 1020 cm-2 for the sources in Fields 1 - 4, respectively. The authors used PIMMS to calculate the count-rate-flux conversion factors assuming the simulated ARFs from AO9 of the Chandra program. . Total galactic H I column densities were determined using Stark et al. (1992, ApJ, 79, 77).

FB_Flux_Error
The uncertainty in the associated parameter value, in erg cm-2 s-1, calculated using the formalism of Gehrels (1986, ApJ, 303, 336).

Hardness_Ratio
The classical hardness (count) ratio HR of the X-ray source defined as (CH - CS)/(CH + CS), where CH and CS are the hard- and soft-band counts, respectively, calculated using the Bayesian estimator of hardness ratio (BEHR) method (Park et al. 2006, ApJ, 652, 610). For more details, see Section 4.4 of the reference paper.

Hardness_Ratio_Lower
The lower 1-sigma bound on the hardness ratio HR of the X-ray source.

Hardness_Ratio_Upper
The upper 1-sigma bound on the hardness ratio HR of the X-ray source.

Flux_Ratio
The hardness flux ratio FR of the X-ray source defined as FR = FHB/FSB, where FHB and FSB are the hard- and soft-band fluxes, respectively, calculated using the Bayesian estimator of hardness ratio (BEHR) method (Park et al. 2006, ApJ, 652, 610). For more details, see Section 4.4 of the reference paper.

Flux_Ratio_Lower
The lower 1-sigma bound on the hardness flux ratio fR of the X-ray source. Sources with unconstrained upper or lower limits due to non-detections are denoted by values of -1.0.

Flux_Ratio_Upper
The upper 1-sigma bound on the hardness flux ratio fR of the X-ray source. Sources with unconstrained upper or lower limits due to non-detections are denoted by values of -1.0.

Field_Number
The XDEEP2 field identifier in which the source is located: 1, 2, 3 or 4.

Opt_Source_Number
The DEEP2 optical source identifier (Coil et al. 2004, ApJ, 617, 765) for the optical counterpart to the X-ray source.

Opt_RA
The Right Ascension of the optical counterpart to the X-ray source in the selected equinox. This was given in J2000.0 decimal degrees to a precision of 10-5 degrees (0.036 arcseconds) in the original table.

Opt_Dec
The Declination of the optical counterpart to the X-ray source in the selected equinox. This was given in J2000.0 decimal degrees to a precision of 10-5 degrees (0.036 arcseconds) in the original table.

Offset
The angular separation between the optical and X-ray source positions, in arcseconds

Redshift
The optical counterpart redshift.

Bayesian_Galaxy_Prob
The Bayesian probability of the object being a galaxy based on the R-band image, where <= 0 means star/compact source while >= 1 means galaxy/extended source: see Coil et al. (2004, ApJ, 617, 765) for more details.

Bmag
The B-band AB magnitude of the optical counterpart to the X-ray source.

Rmag
The R-band AB magnitude of the optical counterpart to the X-ray source.

Imag
The I-band AB magnitude of the optical counterpart to the X-ray source.


Contact Person

Questions regarding the XDEEP2 database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 17-Oct-2012