- ID:
- ivo://nasa.heasarc/clansoid
- Title:
- ChandraLockmanAreaNorthSurvey(CLANS)Optical&IRCatalog
- Short Name:
- CLANSOID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the redshift catalog for the X-ray sources detected in the Chandra Lockman Area North Survey (CLANS). The redshifts for the CLANS field are all new. For fluxes above 10<sup>-14</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> (2-8 keV) the authors have redshifts for 76% of the sources in the CLANS, CLASXS, and CDF-N surveys. They extend the redshift information for the full sample using photometric redshifts. The goal of the OPTX Project is to use these three surveys, 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 optical and infrared photometric catalog for the CLANS X-ray sources is presented here (see the CLANS Browse table for the X-ray information). The CLANS and CLASXS surveys bridge the gap between the ultra-deep pencil-beam surveys, such as the CDFs, and the shallower, very large-area surveys. As a result, they probe the X-ray sources that contribute the bulk of the 2-8 keV X-ray background and cover the flux range of the observed break in the log N - log S distribution. This table was created by the HEASARC in December 2008 based on the electronic version of Table 11 from the paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/clans
- Title:
- Chandra Lockman Area North Survey (CLANS) X-Ray Source Catalog
- Short Name:
- CLANS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the catalogs for the X-ray sources detected in the Chandra Lockman Area North Survey (CLANS). (The information on the optical and infrared counterparts to these sources is contained in the CLANSOID table.) The nine ACIS-I fields which constitute the CLANS cover a solid angle of ~0.6 deg<sup>2</sup> and reach fluxes of 7 x 10<sup>-16</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> (0.5-2 keV) and 3.5 x 10<sup>-15</sup> ergs cm<sup>-2</sup> s<sup>-1</sup> (2-8 keV). The authors find a total of 761 X-ray point sources. The CLANS and CLASXS surveys bridge the gap between the ultra-deep pencil-beam surveys, such as the CDFs, and the shallower, very large-area surveys. As a result, they probe the X-ray sources that contribute the bulk of the 2-8 keV X-ray background and cover the flux range of the observed break in the log N-log S distribution. CLANS consists of nine separate 70 ks Chandra ACIS-I exposures centered at J2000.0 RA and Dec of (10 46,+59 01) (see Table 2 of the reference paper for the full observational details) which were combined to create an 0.6 deg<sup>2</sup> image containing 761 sources. The CLANS observations consist of a raster with an ~2 arcminute overlap between contiguous pointings. Following the prescription in Yang et al. (2004, AJ, 128, 1501) for the CLASXS field, the authors merged the nine individual pointing catalogs to create the final CLANS X-ray catalog. For sources with more than one detection in the nine fields, they used the detection from the observation in which the effective area of the source was the largest. This table was created by the HEASARC in December 2008 based on the electronic versions of Tables 4 and 5 from the paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/champlane
- Title:
- Chandra Multiwavelength Plane Survey Optical ID Catalog
- Short Name:
- CHAMPLANE
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have carried out optical and X-ray spectral analyses on a sample of 136 candidate optical counterparts of X-ray sources found in five Galactic bulge fields included in their Chandra Multiwavelength Plane (ChaMPlane) Survey. They used a combination of optical spectral fitting and quantile X-ray analysis to obtain the hydrogen column density toward each object, and a three-dimensional dust model of the Galaxy to estimate the most probable distance in each case. They present the discovery of a population of stellar coronal emission sources, likely consisting of pre-main-sequence, young main-sequence, and main-sequence stars, as well as a component of active binaries of RS CVn or BY Dra type. They identify one candidate quiescent low-mass X-ray binary with a sub-giant companion, but note that this object may also be an RS CVn system. They report the discovery of 3 new X-ray-detected cataclysmic variables (CVs) in the direction of the Galactic center (at distances <~2 kpc). This number is in excess of predictions made with a simple CV model based on a local CV space density of <~10<sup>-5</sup> pc<sup>-3</sup>, and a scale height of ~200 pc. They discuss several possible reasons for this observed excess in their paper. This table was created by the HEASARC in October 2008 based on the version of Table 5 from the paper which was obtained from the electronic ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/champpsc
- Title:
- Chandra Multiwavelength Project (ChaMP) Point Source Catalog
- Short Name:
- ChaMPPS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table represents the `Main Chandra Multiwavelength Project (ChaMP) X-Ray Point Source Catalog' and contains the basic parameters, photometry, and fluxes of 6512 ChaMP sources in 130 Chandra observations from Chandra Cycles 1 and 2. This table lists fluxes for 2 assumed spectral energy distributions with the photon indices of Gamma=1.4 and Gamma=1.7. This catalog was distributed by the ChaMP team based on the "Chandra Multiwavelength Project: X-ray Point Source Catalog (Kim et al., 2007, ApJS, 169, 401)", and was downloaded from <a href="http://hea-www.harvard.edu/CHAMP/">http://hea-www.harvard.edu/CHAMP/</a>. If you have any comments/questions on this catalog, please contact mkim @ cfa.harvard.edu or dkim @ cfa.harvard.edu. The full Chandra Multiwavelength Project (ChaMP) X-ray point source catalog lists ~ 6800 X-ray sources detected in 149 Chandra observations covering ~ 10 square degrees. The full ChaMP catalog sample is 7 times larger than the initial published ChaMP catalog (Kim et al. 2004, ApJS, 150, 19). The exposure times of the fields in this sample range from 0.9 to 124 ks, corresponding to a deepest X-ray flux limit in the 0.5 - 8.0 keV band of 9 x 10<sup>-16</sup> ergs cm<sup>-2</sup> s<sup>-1</sup>. The ChaMP X-ray data were uniformly reduced and analyzed with ChaMP-specific pipelines and then carefully validated by visual inspection. The ChaMP catalog includes X-ray photometric data in eight different energy bands as well as X-ray spectral hardness ratios and colors, source reliability, detection probability, and positional uncertainties. The false source detection rate is ~1% of all detected ChaMP sources, while the detection probability is better than ~ 95% for sources with counts >~ 30 and off-axis angle <5'. The typical positional offset between ChaMP X-ray source and their SDSS optical counterparts is 0.7" +/- 0.4", derived from ~ 900 matched sources. This HEASARC table contains the main ChaMP catalog of 6512 X-ray point sources in 130 ChaMP fields observed once and in the overlapping fields which had the longest exposures. It does not contain the supplementary ChaMP catalog of 853 sources in 19 ChaMP overlapping fields with shorter exposure times. This table was created by the HEASARC in October 2006 based on the table <a href="http://hea-www.cfa.harvard.edu/CHAMP/IMAGES_DATA/champ_xpc.tab">http://hea-www.cfa.harvard.edu/CHAMP/IMAGES_DATA/champ_xpc.tab</a> on the ChaMP website. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chpngptsrc
- Title:
- Chandra Nearby Galaxies Point Source Catalog
- Short Name:
- ChanNGalPSC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have analyzed Chandra ACIS observations of 32 nearby spiral and elliptical galaxies. The properties (e.g., counts in 3 energy bands, hardness ratios and inferred X-ray luminosities) of the 1441 X-ray point sources that were detected in these galaxies are listed in this table. The total point-source X-ray (0.3 - 8.0 keV) luminosity L<sub>XP</sub> is found to be well correlated with the B-band, K-band, and FIR+UV luminosities of spiral host galaxies, and is well correlated with the B-band and K-band luminosities of elliptical galaxies. This suggests an intimate connection between L<sub>XP</sub> and both the old and the young stellar populations, for which K and FIR+UV luminosities are reasonable proxies for the galaxy mass and the star formation rate (SFR). This table was created by the HEASARC in October 2006 based on CDS table J/ApJ/602/231/tablea1.dat This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/channsgpsc
- Title:
- Chandra Nearby Spiral Galaxies Point Source Catalog
- Short Name:
- ChanNSPiral
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Emission from discrete point sources dominates the X-ray luminosity in spiral galaxies. This table contains the results from a survey of 11 nearby, nearly face-on spiral galaxies observed with the Chandra X-ray Observatory in 22 observations for a total of 869 ks. The galaxies in this sample are at high Galactic latitude to minimize the absorbing column in the line of site, are nearby to minimize source confusion, and span the Hubble sequence for spirals (types 0-7), allowing insights into the X-ray source population of many diverse systems. More than 820 unique point sources are detected in at least one observation within the D25 ellipses of the galaxies. A minimum of 27% of the sources exhibit detectable long- or short-term variability, indicating a source population dominated by accreting XRBs. 17 ultraluminous X-ray sources are detected, with typical rates per galaxy of 1 or 2. In this table, source lists for the 11 galaxies are presented, along with source counts, fluxes, luminosities, X-ray colors, and variability properties. It should be noted that the X-ray source counts presented in this table are raw, background-subtracted counts, so the count rates in sources from the same galaxy that fall on different CCDs cannot be directly compared. The colors presented have been corrected for the differences between front-illuminated and back-illuminated CCDs. This table was created by the HEASARC in November 2006 based on the electronic version of Table 4 obtained from the electronic ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/coup
- Title:
- Chandra Orion Ultradeep Point Source Catalog
- Short Name:
- ChandraOUP
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Chandra Orion Ultradeep Project (COUP) was a deep observation of the Orion Nebula Cluster (ONC) that was obtained with the Chandra X-Ray Observatory's Advanced CCD Imaging Spectrometer (ACIS). This Browse table contains the COUP catalog of more than 1600 X-ray point sources that were detected in the exceptionally deep 2003 January observation, which was an 838 ks exposure made over a continuous period of 13.2 days. The COUP observation provides the most uniform and comprehensive data set on the X-ray emission of normal stars ever obtained in the history of X-ray astronomy. This table was created by the HEASARC in September 2006 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/160/319">CDS catalog J/ApJS/160/319</a>, tables 2, 4, 6, 7, 8, 9, and 10. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gcptsrccxo
- Title:
- Chandra Point Sources in 18 Distant Galaxy Clusters
- Short Name:
- GCPTSRCCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- With the superb angular resolution of the Chandra Observatory, it is now possible to detect X-ray point sources, either embedded in galaxy clusters or along the cluster line of sight, which could not be resolved by previous instruments. This now allows studies of source counts in distant cluster fields. The authors want to analyze the inner region of clusters of galaxies to check for the presence of any over-density of X-ray point sources embedded in the gas diffuse emission. These point sources are possible AGN belonging to the clusters and could contaminate the cluster emission. The authors used a sample of 18 distant (0.25 < z < 1.01) galaxy clusters from the Chandra archive to construct the log N - log S relation, in both the soft and hard energy bands, for the X-ray point sources detected in the central cluster region to be compared with the counts of point sources detected in similarly deep fields without clusters. The authors find a ~2-sigma excess of cluster region sources at the bright end of the log N - log S distribution. The radial distribution of the brightest X-ray point sources confirms this excess and indicates that it is confined to the inner 0.5 Mpc of the cluster region. The results suggest the possible existence of X-ray sources belonging to the cluster (most probably AGN, given their 0.5-10 keV luminosity ranging from 10<sup>43</sup> to 10<sup>44</sup> erg s<sup>-1</sup>): on average one every three clusters. Unlike previous studies, which have mainly investigated the point-source population in the vicinity of the galaxy clusters, the present study analyzes the content of point sources within the 1 Mpc region covered by the cluster extent. This work confirms the findings of other investigators who analyzed the central 1 Mpc region of more massive clusters and/or groups in a similar redshift range. The X-ray source excess found here is much smaller than the excess of radio galaxies found recently in high-z X-ray selected clusters, possibly due to the better sensitivity of the radio observations. The properties of the clusters and of the Chandra exposures in which they were observed are given in Table 1 of the reference paper, and are reproduced below: <pre> Cluster Name z RA (J2000) Dec ObsID ACIS Mode Exp N_H L_sb L_hb h m s d ' " ks [units are below] Abell 2125 0.246 15 41 12 +66 16 01 2207 I VF 79.7 2.77 0.13 0.56 ZW CL 1454.8+2233 0.258 14 57 15 +22 20 33 4192 I VF 91.4 3.22 0.23 0.74 MS 1008.1-1224 0.302 10 10 32 -12 39 23 926 I VF 44.2 6.74 0.44 1.57 ZW CL 0024.0+1652 0.394 00 26 35 +17 09 39 929 S VF 36.7 4.19 0.34 2.22 MS 1621.5+2640 0.426 16 23 36 +26 34 21 546 I F 30.0 3.59 0.81 3.41 RXJ 1701.3+6414 0.453 17 01 24 +64 14 10 547 I VF 49.5 2.59 0.64 2.67 CL 1641+4001 0.464 16 41 53 +40 01 46 3575 I VF 44.0 1.02 0.67 2.62 V 1524.6+0957 0.516 15 24 40 +09 57 48 1664 I VF 49.9 2.92 0.89 3.29 MS 0451.6-0305 0.539 04 54 12 -03 00 53 902 S F 41.5 5.18 0.73 4.12 V 1121+2327 0.562 11 20 57 +23 26 27 1660 I VF 66.9 1.30 0.73 3.00 MS 2053.7-0449 0.583 20 56 21 -04 37 51 1667 I VF 43.5 4.96 1.32 4.91 V 1221+4918 0.700 12 21 26 +49 18 30 1662 I VF 79.4 1.44 1.18 4.62 MS 1137.5+6625 0.782 11 40 22 +66 08 18 536 I VF 117.5 1.18 0.81 4.04 RDCSJ 1317+2911 0.805 13 17 21 +29 11 19 2228 I VF 111.3 1.04 0.85 3.59 RDCSJ 1350+6007 0.805 13 50 48 +60 06 54 2229 I VF 58.3 1.76 1.77 7.26 RXJ 1716.4+6708 0.813 17 16 49 +67 08 26 548 I F 51.5 3.71 2.17 9.45 MS 1054.4-0321 0.830 10 56 59 -03 37 37 512 S F 67.5 3.67 1.07 6.61 WARPJ 1415.1+3612 1.013 14 15 11 +36 12 00 4163 I VF 89.2 1.10 1.93 7.54 </pre> where Exp is the Chandra exposure time in ks corresponding to the nominal exposure filtered to exclude time periods of high background, N_H is the Galactic hydrogen column density in the direction of the cluster of galaxies, in units of 10<sup>20</sup> cm<sup>-2</sup>, and L_sb and L_hb are the limiting luminosities in units of 10<sup>42</sup> erg s<sup>-1</sup> for point sources in the clusters in the 0.5-2.0 keV and 2-10 keV energy bands, respectively. This table was created by the HEASARC in September 2010 based on the electronic version of Table 2 from the reference paper which was obtained from the CDS, their catalog J/A+A/462/449. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/chansexsi
- Title:
- Chandra Serendipitous Extragalactic X-Ray Source ID (SEXSI) Catalog
- Short Name:
- Chan/Seren/ID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Serendipitous Extragalactic X-Ray Source Identification (SEXSI) program is designed to extend greatly the sample of identified extragalactic hard X-ray (2 - 10 keV) sources at intermediate fluxes (~10<sup>-13</sup> to 10<sup>-15</sup> erg/cm<sup>2</sup>/s). SEXSI, which studies sources selected from more than 2 deg<sup>2</sup>, provides an essential complement to the Chandra Deep Fields, which reach depths of 5 x 10<sup>-16</sup> erg/cm<sup>2</sup>/s (2 - 10 keV) but over a total area of less than 0.2 deg<sup>2</sup>. In their published paper, the authors describe the characteristics of the survey and their X-ray data analysis methodology. They present the cumulative flux distribution for the X-ray sample of 1034 hard sources and discuss the distribution of spectral hardness ratios. Their log N -log S in this intermediate flux range connects to those found in the Deep Fields, and by combining the data sets, they constrain the hard X-ray population over the flux range in which the differential number counts change slope and from which the bulk of the 2 - 10 keV X-ray background arises. They further investigate the log N - log S distribution separately for soft and hard sources in the sample, finding that while a clear change in slope is seen for the softer sample, the hardest sources are well described by a single power law down to the faintest fluxes, consistent with the notion that they lie at lower average redshift. In the SEXSI program, fields were selected with high Galactic latitude (|b| > 20 degrees) and with declinations accessible to the optical facilities available to the authors (declination > -20 degrees). They used observations taken with Chandra's Advanced Camera for Imaging Spectroscopy (ACIS I- and S-modes; Bautz et al., 1998, Proc. SPIE, 3444, 210) only (for sensitivity in the hard band). All the fields presented in this paper have data that are available in the Chandra public archive. This table was created by the HEASARC in June 2004 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/596/944/table4">CDS Catalog J/ApJ/596/944/table4</a>.dat which is a representation of Table 4 from the published version. Note that it does not include the Soft-Band-Only Source Catalog (Table 6 in the published version of the paper). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/csc
- Title:
- Chandra Source Catalog, v2.0
- Short Name:
- CSC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Chandra Source Catalog (CSC) is the definitive catalog of X-ray sources detected by the Chandra X-ray Observatory. By combining Chandra's sub-arcsecond on-axis spatial resolution and low instrumental background with consistent data processing, the CSC delivers a wide variety of uniformly calibrated properties and science ready data products for detected sources over four decades of flux. The second major release of the catalog, CSC 2.0, includes measured properties for 317,167 unique compact and extended X-ray sources in the sky, allowing statistical analysis of large samples, as well as individual source studies in the "Master Sources" table, provided herein. The extracted properties are provided for 928,280 individual observation detections, identified in 10,382 Chandra ACIS and HRC-I imaging observations released publicly through the end of 2014, at the <a href="https://cxc.harvard.edu/csc/about.html">Chandra X-ray Center</a>. CSC 2.0 includes -- as an "alpha" release -- photometric properties for 1,299 highly extended (> ~30") sources, together with surface brightness polygons for several contour levels. The sensitivity limit for compact sources in CSC 2.0 is ~5 net counts (a factor of >~2 better than the previous catalog release). This improvement is achieved by using a two-stage approach that involves co-adding multiple observations of the same field prior to source detection, and then using an optimized source detection method. For each X-ray detection and source, the catalog provides a detailed set of more than 100 tabulated positional, spatial, photometric, spectral, and temporal properties (each with associated lower and upper confidence intervals and measured in multiple energy bands). The catalog Bayesian aperture photometry code produces robust photometric probability density functions (PDFs), even in crowded fields and for low count detections. Release 2 uses a Bayesian Blocks analysis to identify multiple observations of the same source that have similar photometric properties, and these are analyzed simultaneously to improve S/N. The energy bands used to derive many of the CSC properties are defined in Table 4 of the reference paper: ultrasoft (u: 0.2-0.5 keV), soft (s: 0.5-1.2 keV), medium (m: 1.2-2.0 keV), hard (h: 2.0-7.0) and broad (b: 0.5-7.0 keV) for the ACIS energy bands, and wide (w: 0.1-10.0 keV) for the HRC energy band. The energy bands are chosen to optimize the detectability of X-ray sources while simultaneously maximizing the discrimination between different spectral shapes on X-ray color-color diagrams. Numerous source-specific catalog properties are evaluated within defined apertures. The authors define the "PSF 90% ECF aperture" for each source to be the ellipse that encloses 90% of the total counts in a model PSF centered on the source position. Because the size of the PSF is energy-dependent, the dimensions of the PSF 90% ECF aperture vary with energy band. They define the "source region aperture" for each source to be equal to the corresponding 3-sigma source region ellipse included in the merged source list, scaled by a factor of 1.5. Like the PSF 90% ECF aperture, the source region aperture is also centered on the source position, but the dimensions of the aperture are independent of energy band. This database table was ingested by the HEASARC in November 2019 and is based on a download of the online version of the Chandra Source Catalog, v2.0, at the CXC using the CLI. Refer to <a href="http://cxc.harvard.edu/csc/">http://cxc.harvard.edu/csc/</a> for details. This is a service provided by NASA HEASARC .
