- ID:
- ivo://nasa.heasarc/cdfn2msnew
- Title:
- Chandra Deep Field North 2-Megasecond Improved Point Source Catalog
- Short Name:
- CDFN2MSNEW
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the improved point-source catalog for the 2-Ms Chandra Deep Field-North (CDF-N) Survey, implementing a number of recent improvements in Chandra source-cataloguing methodology. For the CDF-N, the main catalog (entries from which are indicated with parameter values of source_sample = "Main" in this HEASARC representation) contains 683 X-ray sources detected with wavdetect at a false-positive probability threshold of 10<sup>-5</sup> that also satisfy a binomial-probability source-selection criterion of P <= 0.004. Such an approach maximizes the number of reliable sources detected: a total of 196 main-catalog sources are new compared to the Alexander et al. (2003, AJ, 126, 539) CDF-N main catalog. The authors also provide a CDF-N supplementary catalog that consist of 72 sources (entries from which are indicated with parameter values of source_sample = "Supp" in this HEASARC representation) detected at the same wavdetect threshold and having P of 0.004-0.1 and K<sub>s</sub> <= 22.9 mag counterparts. For all 755 CDF-N sources, including the 234 newly detected ones (these being generally fainter and more obscured), the authors determine X-ray source positions utilizing centroid and matched-filter techniques; they also provide multi-wavelength identifications, apparent magnitudes of counterparts, spectroscopic and/or photometric redshifts, basic source classifications, and estimates of observed active galactic nucleus and galaxy source densities around respective field centers. Simulations show that the CDF-N main catalog is highly reliable and reasonably complete. Background and sensitivity analyses indicate that the on-axis mean flux limits reached represent a factor of ~1.5-2.0 improvement over the previous CDF-N limit. The 2 Ms CDF-N consists of a total of 20 separate Chandra observations taken between 1999 November 13 and 2002 February 22 with ACIS (see Alexander et al., 2003, AJ, 126, 539 for more details). This table was created by the HEASARC in August 2016 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/224/15">CDS Catalog J/ApJS/224/15</a> files table3.dat (the main source catalog) and table6.dat (the supplementary source catalog). This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/cdfn2msoid
- Title:
- ChandraDeepFieldNorth2-MegasecondOptical&IRCatalog
- Short Name:
- Chan/DF2S
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Chandra Deep Field North (CDFN) 2-Megasecond (2Ms) Optical and IR Catalog is an optical and near-infrared catalog for the X-ray sources in the 2Ms Chandra observation of the Hubble Deep Field North region. It has high-quality multicolor imaging data for all 503 X-ray point sources in the X-ray-selected catalog and reliable spectroscopic redshifts for 284. The authors have spectroscopically identified six high-redshift (z > 1) type II quasars (L<sub>2-8keV</sub> > 10<sup>44</sup> ergs/s) in their sample. The spectroscopic completeness for the R <= 24 sources is 87%. The spectroscopic redshift distribution shows two broad redshift spikes that have clearly grown over those originally seen in the 1Ms exposure. The spectroscopically identified extragalactic sources already comprise 75% of the measured 2-8 keV light. Redshift slices versus 2-8 keV flux show that an impressive 54% of the measured 2-8 keV light arises from sources at z < 1 and 68% from sources at z < 2. The X-ray sample is presented in Alexander et al. (2003, AJ, 126, 539, hereafter ABB2003) and in <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/126/539">CDS Catalog <J/AJ/126/539></a>, and is also available in the HEASARC Browse system as the CHANDFN2MS table. The optical imaging data consist of Johnson B, Johnson V, Cousins R, Cousins I, and Sloan z' observations obtained with the Subaru prime-focus camera Suprime-Cam on the Subaru 8.2m telescope during February-April of 2001 and 2002. This table was created by the HEASARC in April 2004 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/126/632/table1a">CDS Catalog J/AJ/126/632/table1a</a>.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cdfn2msoi2
- Title:
- ChandraDeepFieldNorthUpdatedOptical&IRCatalog
- Short Name:
- CDFN2MSOI2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the redshift catalog for the X-ray sources detected in the Chandra Deep Field-North (CDF-N). The catalog for the CDF-N 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 Large-Area Synoptic X-Ray Survey (CLASXS) 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 ultra-deep pencil-beam surveys, such as the Chandra Deep Fields, and the shallower, very large-area surveys. This table also contains updated optical and infrared photometric data for the X-ray sources in the CDF-N. Typical photometric uncertainties are given in Section 3.6 of the reference paper (Trouille et al. 2008). The X-ray information for the sources detected in the CDF-N 2-megasecond exposure which was published in Alexander et al. (2003, AJ, 126, 539) is available as the HEASARC CHANDFN2MS table, while the earlier catalog which listed information about optical and infrared counterparts (Barger et al. 2003, AJ, 126, 632) is available as the HEASARC CDFN2MSOID table. This table was created by the HEASARC in January 2009 based on the electronic version of Table 13 from the paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cdfsagncxo
- Title:
- Chandra Deep Field South AGN Spectral Properties Catalog
- Short Name:
- CDFSAGNCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of a detailed X-ray spectral analysis of the sources in the 1 Ms catalog of the Chandra Deep Field South (CDFS, Giacconi et al. 2002, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/139/369">CDS Cat. J/ApJS/139/369</a>, available in Browse as the CHANDFS1MS table), taking advantage of optical spectroscopy and photometric redshifts for 321 extragalactic sources out of the total sample of 347 sources. As a default spectral model, the authors adopt a power law with a slope Gamma with an intrinsic redshifted absorption N<sub>H</sub>, a fixed Galactic absorption and an unresolved Fe emission line. For 82 X-ray bright sources, they are able to perform the X-ray spectral analysis leaving both Gamma and N<sub>H</sub> free. The weighted mean value for the slope of the power law is 1.75 +/- 0.02, and the distribution of best fit values shows an intrinsic dispersion of 0.30. The authors do not find hints of a correlation between the spectral index Gamma and the intrinsic absorption column density N<sub>H</sub>. They then investigate the absorption distribution for the whole sample, deriving the N<sub>H</sub> values in faint sources by fixing Gamma to be 1.8. The authors find that the fraction of absorbed sources (with N<sub>H</sub> > 10<sup>22</sup> cm<sup>-2</sup>) in the sample is constant (at the level of about 75%) or moderately increasing with redshift. Finally, they compare the optical classification to the X-ray spectral properties, confirming that the correspondence of unabsorbed (absorbed) X-ray sources to optical type I (type II) AGN is accurate for at least 80% of the sources with spectral identification (1/3 of the total X-ray sample). This table was created by the HEASARC in August 2007 primarily based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/451/457">CDS Catalog J/A+A/451/457</a> file table1.dat. The positions of the X-ray sources were taken from <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/139/369">CDS Catalog J/ApJS/139/369</a> (Giacconi et al. 2002), except for that of source number 901 which was taken from Table 5 of Szokoly et al. (2004, ApJS, 155, 271). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chandfs4ms
- Title:
- Chandra Deep Field South 4-Megasecond Catalog
- Short Name:
- CHANDFS4MS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the main Chandra source catalog for the 4 megasecond (Ms) Chandra Deep Field-South (CDF-S), which is the deepest Chandra survey to date and covers an area of 464.5 arcmin<sup>2</sup>. It contains 740 X-ray sources that are detected with wavdetect at a false-positive probability threshold of 10<sup>-5</sup> in at least one of three X-ray bands (0.5-8 keV, full band; 0.5-2 keV, soft band; and 2-8 keV, hard band) and also satisfy a binomial-probability source-selection criterion of P < 0.004 (i.e., the probability of sources not being real is less than 0.004); this approach is designed to maximize the number of reliable sources detected. A total of 300 main-catalog sources are new compared to the previous 2 Ms CDF-S main-catalog (the HEASARC CHANDFS2MS table) sources. The authors determined X-ray source positions using centroid and matched-filter techniques and obtained a median positional uncertainty of ~0.42 arcseconds. In their paper, they also provided a supplementary catalog (not included in this HEASARC table), which consists of 36 sources that are detected with wavdetect at a false-positive probability threshold of 10<sup>-5</sup>, satisfy the condition of 0.004 < P < 0.1, and have an optical counterpart with R < 24. Multiwavelength identifications, basic optical/infrared/radio photometry, and spectroscopic/photometric redshifts are provided for the X-ray sources in the main and supplementary catalogs. Seven hundred sixteen (~97%) of the 740 main-catalog sources have multiwavelength counterparts, with 673 (~94% of 716) having either spectroscopic or photometric redshifts. The 740 main-catalog sources span broad ranges of full-band flux and 0.5-8 keV luminosity; the 300 new main-catalog sources span similar ranges although they tend to be systematically lower. Basic analyses of the X-ray and multiwavelength properties of the sources indicate that >75% of the main-catalog sources are active galactic nuclei (AGNs); of the 300 new main-catalog sources, about 35% are likely normal and starburst galaxies, reflecting the rise of normal and starburst galaxies at the very faint flux levels uniquely accessible to the 4 Ms CDF-S. Near the center of the 4 Ms CDF-S (i.e., within an off-axis angle of 3'), the observed AGN and galaxy source densities have reached 9800 (+1300,-1100) deg<sup>-2</sup> and 6900 (+1100,-900) deg<sup>-2</sup>, respectively. Simulations show that the main catalog is highly reliable and is reasonably complete. The mean backgrounds (corrected for vignetting and exposure-time variations) are 0.063 and 0.178 counts Ms<sup>-1</sup> pixel<sup>-1</sup> (for a pixel size of 0.492 arcseconds) for the soft and hard bands, respectively; the majority of the pixels have zero background counts. The 4 Ms CDF-S reaches on-axis flux limits of ~3.2 x 10<sup>-17</sup>, 9.1 x 10<sup>-18</sup>, and 5.5 x 10<sup>-17</sup> erg cm<sup>-2</sup> s<sup>-1</sup> for the full, soft, and hard bands, respectively. An increase in the CDF-S exposure time by a factor of ~2-2.5 would provide further significant gains and probe key unexplored discovery space. This HEASARC table comprises Table 3 from the reference paper, the Main Chandra Source Catalog of 740 X-ray sources. The 36 optically bright Chandra sources that were listed in Table 6 of the reference paper are thus not included herein. This table was created by the HEASARC in July 2011 based on an electronic version of Table 3 from the reference paper which was obtained from the ApJS web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chandfs1ms
- Title:
- Chandra Deep Field South 1-Megasecond Catalog
- Short Name:
- CDFS1MS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Chandra Deep Field South (CDFS) 1-Megasecond Catalog is the source catalog obtained from a 942 kilosecond exposure, using the Advanced CCD Imaging Spectrometer (ACIS-I) on the Chandra X-ray Observatory. Eleven individual pointings made between 1999 October and 2000 December were combined to generate the final image used for object detection. Catalog generation proceeded simultaneously using two different methods: a method of the authors' own design using a modified version of the SExtractor algorithm, and a wavelet transform technique developed specifically for Chandra observations. The detection threshold was set in order to have less than 10 spurious sources, as assessed by extensive simulations. The catalog as published was subdivided into four sections: the primary list consisting of objects common to the two detection methods, two secondary lists containing sources which were detected by either the SExtractor algorithm alone or by the wavelet technique alone, and the fourth list consisting of possible diffuse or extended sources. The flux limits at the aimpoint for the soft (0.5 - 2 keV) and hard (2 - 10 keV) bands are 5.5 x 10<sup>-17</sup> erg/s/cm<sup>2</sup> and 4.5 x 10<sup>-16</sup> erg/s/cm<sup>2</sup>, respectively. The total number of sources is 346; out of them, 307 were detected in the 0.5 - 2 keV band, and 251 in the 2 - 10 keV band. Optical identifications are also presented for the catalogued sources. The primary optical data are R band imaging from VLT/FORS1 to a depth of R ~ 26.5 (Vega). In regions of the field not covered by the VLT/FORS1 deep imaging, the authors use R-band data obtained with the Wide Field Imager (WFI) on the ESO-MPI 2.2 m telescope, as part of the ESO Imaging Survey (EIS), which cover the entire X-ray survey. The FORS1/Chandra offsets are small, ~1 arcsecond. Coordinate cross-correlation finds 85% of the Chandra sources covered by FORS1 R to have counterparts within the 3-sigma error box (>~1.5 arcseconds, depending on off-axis angle and X-ray signal-to-noise). The unidentified fraction of sources, approximately 10% - 15%, is close to the limit expected from the observed X-ray flux to R-band ratio distribution for the identified sample. This online catalog was created by the HEASARC in June 2002 based on machine-readable versions of 2, 3 and 4 of Giacconi et al. (2002) that were obtained from the CDS. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chandfs2ms
- Title:
- Chandra Deep Field South 2-Megasecond Catalog
- Short Name:
- CHANDFS2MS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains point-source catalogs for the ~2 Ms exposure of the Chandra Deep Field-South (CDF-S) this is one of the two most sensitive X-ray surveys ever performed. The survey covers an area of ~436 arcmin<sup>2</sup> and reaches on-axis sensitivity limits of ~1.9 x 10<sup>-17</sup> and ~1.3 x 10<sup>-16</sup> erg cm<sup>-2</sup> s<sup>-1</sup> for the 0.5-2.0 and 2-8 keV bands, respectively. Four hundred and sixty-two X-ray point sources (source_sample = 'Main CDF-S' in this table) are detected in at least one of three X-ray bands that were searched; 135 of these sources are new compared to the previous ~1 Ms CDF-S detections. Source positions are determined using centroid and matched-filter techniques; the median positional uncertainty is ~0.36". The X-ray-to-optical flux ratios of the newly detected sources indicate a variety of source types; ~55% of them appear to be active galactic nuclei, while ~45% appear to be starburst and normal galaxies. This table contains, in addition to the main Chandra catalog, the supplementary catalog of 86 X-ray sources (source_sample = 'CDF-S + E-CDF-S' in this table) in the ~2 Ms CDF-S footprint that was created by merging the ~250 ks Extended Chandra Deep Field-South with the CDF-S; this approach provides additional sensitivity in the outer portions of the CDF-S. This table also contains a second supplementary catalog (source_sample = 'Optically Bright' in this table) of 30 X-ray sources which was constructed by matching lower significance X-ray sources to bright optical counterparts (R < 23.8); the majority of these sources appear to be starburst and normal galaxies. The total number of sources in this table, which contains the main and 2 supplementary catalogs, is thus 578. Optical R-band counterparts and basic optical and infrared photometry are provided for the X-ray sources in the main and supplementary catalogs. The authors also include existing spectroscopic redshifts for 224 of the X-ray sources. The average backgrounds in the 0.5-2.0 and 2-8 keV bands are 0.066 and 0.167 counts Ms<sup>-1</sup> pixel<sup>-1</sup>, respectively, and the background counts follow Poisson distributions. The effective exposure times and sensitivity limits of the CDF-S are now comparable to those of the ~2 Ms Chandra Deep Field-North (CDF-N). In their paper, the authors also present cumulative number counts for the main catalog and compare the results to those for the CDF-N. The soft-band number counts for these two fields agree well with each other at fluxes higher than ~2 x 10<sup>-16</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, while the CDF-S number counts are up to ~25% smaller than those for the CDF-N at fluxes below ~2 x 10<sup>-16</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the soft band and ~2 x 10<sup>-15</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the hard band, suggesting small field-to-field variations. This table was created by the HEASARC in December 2008 based on the electronic version of Tables 2, 5 and 6 from the reference paper which were obtained from the ApJ web site. It was last modified by the HEASARC in July 2011. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chandfs7ms
- Title:
- Chandra Deep Field-South 7-Megasecond X-Ray Source Catalog
- Short Name:
- CHANDFS7MS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the X-ray source catalogs for the ~7 Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2 square arcminutes. Utilizing WAVDETECT for initial source detection and ACIS Extract for photometric extraction and significance assessment, the authors have created a main source catalog (entries with source_sample = 'M' in this HEASARC table) containing 1,008 sources that are detected in up to three X-ray bands: 0.5-7.0 keV, 0.5-2.0 keV, and 2-7 keV. A supplementary source catalog entries with source_sample = 'S' in this HEASARC table) is also provided, including 47 lower-significance sources that have bright (K<sub>s</sub> <~ 23<sup>m</sup>) near-infrared (NIR) counterparts. The authors have identified multiwavelength counterparts for 992 (98.4%) of the 1,008 main-catalog sources, and they have collected redshifts for 986 of these sources, including 653 spectroscopic redshifts and 333 photometric redshifts. Based on the X-ray and multiwavelength properties, the authors have identified 711 active galactic nuclei (AGNs) from the main-catalog sources. Compared to the previous ~4 Ms CDF-S catalogs, 291 of the main-catalog sources are new detections. The observations utilized in this survey have achieved unprecedented X-ray sensitivity with average flux limits over the central ~1 arcmin<sup>2</sup> region of ~1.9 x 10<sup>-17</sup>, 6.4 x 10<sup>-18</sup>, and 2.7 x 10<sup>-17</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the three X-ray bands, respectively. In the reference paper, the authors provide cumulative number-count measurements observing, for the first time, that normal galaxies start to dominate the X-ray source population at the faintest 0.5-2.0 keV flux levels. The highest X-ray source density reaches ~50,500 deg<sup>-2</sup>, and 47% +/- 4% of these sources are AGNs (~23,900 deg<sup>-2</sup>). The authors adopted a binomial no-source probability value, P<sub>B</sub> < 0.007 as the criterion to prune their initial candidate source list and generate a main source catalog, which includes 1,008 sources with a ~97% multiwavelength-identification rate. This adopted P<sub>B</sub> threshold will have inevitably rejected real X-ray sources. To recover some of these real sources, the authors created a supplementary source catalog that contains lower-significance X-ray sources that have bright optical/NIR counterparts; the chance of a bright optical/NIR source being associated with a spurious X-ray detection is quite small. A total of 47 candidate CDF-S sources having 0.007 <= P<sub>B</sub> < 0.1 are associated with bright, K<sub>s</sub> <= 23<sup>m</sup>, TENIS sources, where the false-match rate is only 1.7%, and these 47 sources constitute the supplementary catalog. A Galactic column density of N<sub>H,Gal</sub> = 8.8 * 10<sup>19</sup> cm<sup>-2</sup> along the line of sight to the CDF-S is assumed in this study. All quoted magnitudes are in the AB system. A cosmology with H<sub>0</sub> = 67.8 km s<sup>-1</sup> Mpc<sup>-1</sup>, Omega<sub>M</sub> = 0.308, and Omega<sub>Lambda</sub> = 0.692 (Planck Collaboration et al. 2016 values) is used to calculate luminosities. This HEASARC table contains the 1,008 sources from the main Chandra source catalog (these entries are identified by the HEASARC-created source_sample parameter being set to 'M' in this table) and the 47 lower-significance sources from the supplementary NIR-bright Chandra source catalog (these entries are identified by the HEASARC-created source_sample parameter being set to 'S' in this table). This table thus has 1,055 entries. This table was created by the HEASARC in March 2017 based upon electronic versions of Tables 4 and 5, the 'Main Chandra Source Catalog' and the 'Supplementary NIR-Bright Chandra Source Catalog', respectively, which were obtained from the ApJS website. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chanextdfs
- Title:
- Chandra Extended Deep Field South Survey Point Source Catalog
- Short Name:
- ChanDFSS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the combined point-source catalogs for the Extended Chandra Deep Field- South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250 ks Chandra observations covering an approximately square region of total solid angle ~0.3 square degrees, which flank the existing ~1 Ms Chandra Deep Field-South (CDF-S). The survey reaches sensitivity limits of ~1.1 x 10<sup>-16</sup> and ~6.7 x 10<sup>-16</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> for the 0.5-2.0 and 2-8 keV bands, respectively. 762 distinct X-ray point sources are detected within the E-CDF-S exposure; 589 of these sources are new (i.e., not previously detected in the ~1 Ms CDF-S). This brings the total number of X-ray point sources detected in the E-CDF-S region to 915 (via the E-CDF-S and ~1 Ms CDF-S observations). Source positions are determined using matched-filter and centroiding techniques; the median positional uncertainty is ~0.35". The basic X-ray and optical properties of these sources indicate a variety of source types, although absorbed active galactic nuclei (AGNs) seem to dominate. In addition to the main Chandra catalog, this table contains the supplementary source catalog with 33 lower-significance X-ray point sources that have bright optical counterparts (R < 23 mag). These sources generally have X-ray-to-optical flux ratios expected for normal and starburst galaxies, which lack a strong AGN component. The basic number-count results for the main Chandra catalog are in good agreement with the ~1 Ms CDF-S for sources with 0.5-2.0 and 2-8 keV fluxes greater than 3 x 10<sup>-16</sup> and 1 x 10<sup>-15</sup> ergs cm<sup>-2</sup> s<sup>-1</sup>, respectively. This HEASARC table contains 809 entries: 762 entries corresponding to the 762 sources listed in the main catalog (Table 2 of the published paper), 14 sources from the cross-field source list (Table 3) which give properties for sources which were detected in more than one observational sources, e.g. there are two entries for the source with source_number = 367, one entry coming from the main catalog, the other entry from the cross-field catalog, and 33 entries corresponding to the 33 sources in the supplementary, optically bright source catalog (Table 6). The HEASARC has created a new parameter called source_type to identify from which of these 3 original tables any given entry comes from; it is set to 'main', 'crossfield' and 'supplement' for entries from Tables 2, 3, and 6, respectively. This online catalog was created by the HEASARC in January 2006 based on machine-readable versions of tables 2, 3, and 6 from the paper which were obtained from the ApJ website. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/changbscat
- Title:
- Chandra Galactic Bulge Survey Full X-Ray Point Source Catalog
- Short Name:
- CHANGBSCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the Chandra source list for the entire area of the Galactic Bulge Survey (GBS) based on the lists provided in Jonker et al. (2011, ApJ, 194, 18: Paper I) and Jonker et al. (2014, ApJS, 210, 18: Paper II). The previous version of this table, based solely on the data presented in Paper I, contained the Chandra source list based on the first three-quarters of the GBS that had been observed as of the date of writing of that paper. Among the goals of the GBS are constraining the neutron star (NS) equation of state and the black hole (BH) mass distribution via the identification of eclipsing NS and BH low-mass X-ray binaries (LMXBs). The latter goal will, in addition, be obtained by significantly enlarging the number of BH systems for which a BH mass can be derived. Further goals include constraining X-ray binary formation scenarios, in particular the common envelope phase and the occurrence of kicks, via source-type number counts and an investigation of the spatial distribution of X-ray binaries, respectively. The GBS targets two strips of 6 degrees by 1 degrees (12 deg<sup>2</sup> in total), one above (1<sup>o</sup> < b < 2<sup>o</sup>) and the other below (-2<sup>o</sup> < b < -1<sup>o</sup>) the Galactic plane in the direction of the Galactic center at X-ray, optical and near-infrared wavelengths. By avoiding the Galactic plane (-1<sup>o</sup> < b < 1<sup>o</sup>) the authors limit the influence of extinction on the X-ray and optical emission but still sample relatively large number densities of sources. The survey is designed such that a large fraction of the X-ray sources can be identified from their optical spectra. The X-ray survey, by design, covers a large area on the sky while the depth is shallow, using 2 ks per Chandra pointing. In this way, the authors maximize the predicted number ratio of (quiescent) LMXBs to cataclysmic variables. The survey is approximately homogeneous in depth to a 0.5-10 keV flux of 7.7 x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup>. As of Paper I, the authors had covered about three-fourths (8.3 deg<sup>2</sup>) of the projected survey area with Chandra observations providing 1234 unique X-ray sources. In Paper II, the authors find 424 additional X-ray sources in the 63 Chandra observations that they report on there. In the papers, the authors discuss the characteristics and the X-ray variability of the brightest of the sources as well as the radio properties from existing radio surveys. They point out an interesting asymmetry in the number of X-ray sources as a function of their Galactic l and b coordinates which is probably caused by differences in average extinction towards the different parts of the GBS survey area. This table was originally ingested by the HEASARC in June 2011 based on an electronic version of Table 3 from Paper I which was obtained from the ApJS web site. The current version of this table was ingested by the HEASARC in January 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/210">CDS catalog J/ApJS/210</a>,18 file cxogbs.dat, which appears to be the combination of an Table 3 from Paper I with Table 1 from Paper II. This is a service provided by NASA HEASARC .
