- ID:
- ivo://nasa.heasarc/aegisx
- Title:
- AEGIS-X Chandra Extended Groth Strip X-Ray Point Source Catalog
- Short Name:
- AEGISX
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the X-ray sources detected in the AEGIS-X survey, a series of deep Chandra ACIS-I observations of the Extended Groth Strip (EGS). The survey comprises pointings at eight separate positions, each with nominal exposure of 200 ks, covering a total area of approximately 0.67 deg<sup>2</sup> in a strip of length 2 degrees. In their paper, the authors describe in detail an updated version of the data reduction and point-source-detection algorithms used to analyze these data. A total of 1325 band-merged sources have been found to a Poisson probability limit of 4 x 10<sup>-6</sup>, with limiting fluxes of 5.3 x 10<sup>-17</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the soft (0.5 - 2 keV) band and 3.8 x 10<sup>-16</sup> erg cm<sup>-2</sup> s<sup>-1</sup> in the hard (2 - 10 keV) band. They present simulations verifying the validity of their source-detection procedure and showing a very small, <1.5%, contamination rate from spurious sources. Optical/NIR counterparts have been identified from the DEEP2, CFHTLS, and Spitzer/Infrared Array Camera (IRAC) surveys of the same region. Using a likelihood ratio method, they find optical counterparts for 76% of their sources, complete to R<sub>AB</sub> = 24.1, and, of the 66% of the sources that have IRAC coverage, 94% have a counterpart to a limit of 0.9 uJy at 3.6 um (m<sub>AB</sub> = 23.8). After accounting for (small) positional offsets in the eight Chandra fields, the astrometric accuracy of Chandra positions is found to be 0.8 arcseconds rms; however, this number depends both on the off-axis angle and the number of detected counts for a given source. This table was created by the HEASARC in February 2009 based on the electronic versions of Tables 9, 10 and 11 from the paper which were obtained from the Astrophysical Journal web site. It is also available from the CDS at <a href="https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/180/102">https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/180/102</a>. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/aegisxdcxo
- Title:
- AEGIS-X Deep Survey Chandra X-Ray Point Source Catalog
- Short Name:
- AEGISXDCXO
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table is based on the results of deep Chandra imaging of the central region of the Extended Groth Strip, the AEGIS-X Deep (AEGIS-XD) survey. When combined with previous Chandra observations of a wider area of the strip, AEGIS-X Wide (AEGIS-XW), these provide data to a nominal exposure depth of 800ks in the three central ACIS-I fields, a region of approximately 0.29 deg<sup>2</sup>. This is currently the third deepest X-ray survey in existence; a factor ~2-3 shallower than the Chandra Deep Fields (CDFs), but over an area ~3 times greater than each CDF. This table contains a catalog of 937 point sources detected in the deep Chandra observations, along with identifications of the X-ray sources from deep ground-based, Spitzer, GALEX, and Hubble Space Telescope imaging. Using a likelihood ratio analysis, the authors associate multiband counterparts for 929/937 of their X-ray sources, with an estimated 95% reliability,making the identification completeness approximately 94% in a statistical sense. Reliable spectroscopic redshifts for 353 of the X-ray sources are available predominantly from Keck (DEEP2/3) and MMT Hectospec, so the current spectroscopic completeness is ~38%. For the remainder of the X-ray sources, the authors compute photometric redshifts based on multiband photometry in up to 35 bands from the UV to mid-IR. Particular attention is given to the fact that the vast majority of the X-ray sources are active galactic nuclei and require hybrid templates. The photometric redshifts have a mean accuracy sigma = 0.04 and an outlier fraction of approximately 5%, reaching sigma = 0.03 with less than 4% outliers in the area covered by CANDELS. The new AEGIS-XD Chandra data were taken at three nominal pointing positions, which the authors have designated AEGIS-1, AEGIS-2, and AEGIS-3. These observations were all taken in the time period 2007 December 11 to 2009 June 26 using the ACIS-I instrument. The centers of the 3 AEGIS fields correspond fairly closely to those of the EGS-3, EGS-4, and EGS-5 fields of Laird et al. (2009, ApJS, 180, 102). The Rainbow Cosmological Surveys Database (<a href="http://rainbowx.fis.ucm.es/Rainbow_Database/Home.html">http://rainbowx.fis.ucm.es/Rainbow_Database/Home.html</a>; see Section 4 of the reference paper for more details) contains many multiwavelength photometric datasets giving information on optical and infrared sources in these fields. The characteristics of these datasets are given in Table 7 of the reference paper. This table was created by the HEASARC in February 2016 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/220/10">CDS catalog J/ApJS/220/10</a> files table11.dat, table12.dat, table13.dat, table14.dat and table15.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/aknepdfcxo
- Title:
- Akari North Ecliptic Pole Deep Field Chandra X-Ray Point Source Catalog
- Short Name:
- AKNEPDFCXO
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from the 300-ks Chandra survey in the AKARI North Ecliptic Pole (NEP) deep field. This field has a unique set of 9-band infrared photometry covering 2-24 micron from the AKARI Infrared Camera, including mid-infrared (MIR) bands not covered by Spitzer. The survey is one of the deepest ever achieved at ~15 micron, and is by far the widest among those with similar depths in the MIR. This makes this field unique for the MIR-selection of AGN at z ~1. The authors have designed a source detection procedure, which performs joint Maximum Likelihood PSF fits on all of their 15 mosaicked Chandra pointings covering an area of 0.34 square degrees. The procedure has been highly optimized and tested by simulations. A point source catalog with photometry and Bayesian-based 90%-confidence upper limits in the 0.5-7, 0.5-2, 2-7, 2-4, and 4-7 keV bands has been produced. The catalog contains 457 X-ray sources and the spurious fraction is estimated to be ~1.7%. Sensitivity and 90%-confidence upper flux limits maps in all bands are provided as well. In their study, the authors searched for optical MIR counterparts in the central 0.25 square degrees, where deep Subaru Suprime-Cam multi-band images exist. Among the 377 X-ray sources detected therein, ~80% have optical counterparts and ~60% also have AKARI mid-IR counterparts. The authors cross-matched their X-ray sources with MIR-selected AGN from Hanami et al. (2012, PASJ, 64, 70). Around 30% of all AGN that have MID-IR SEDs purely explainable by AGN activity are strong Compton-thick AGN candidates. The source catalog contained in this table uses an internal threshold of ML = 9.5 which corresponds to ML<sub>empir</sub> ~12 (see Sect. 4.3.3 of the reference paper for more details). In total, 457 sources are detected, of which 377 objects fall in the deep Subaru imaging region (shown in Figure 1 of the reference paper). This catalog is designed to identify X-ray emitting objects in the Chandra/AKARI NEP deep field. Together with the optimized cross-identification procedure, the clear advantage of the catalog is the very high reliability, while the catalog sacrifices completeness for objects with low counts (see Figure 9 in the paper). Only ~1.7% of the objects listed in the source catalog are expected to be spurious source detections. The two sources that have an ML-threshold in the 0.5-7 keV band below 9.5 originate from a 0.5-7 keV single-band source detection run. To quote similar ML values for all objects, the authors list the total 0.5-7 keV ML values from the joint 3-energy band source detection run. The listed counts, count rates, fluxes, and the corresponding uncertainties in the 0.5-7 keV band are taken from the single-band detection run. Considering the uncertainty in the astrometric calibration, all sources should be considered as possible X-ray counterparts that are within a radius of r<sub>match</sub> = sqrt(sigma<sub>total</sub><sup>2</sup>+sigma<sub>astro</sub><sup>2</sup>), with sigma<sub>total</sub> = 5 * sqrt(sigma<sub>sys</sub><sup>2</sup>+sigma<sub>stat</sub><sup>2</sup>) and sigma<sub>sys</sub> = 0.1 arcseconds and sigma<sub>astro</sub> = 0.2 arcseconds (astrometric uncertainty). The authors also created a low-probability source catalog (not contained in this present HEASARC table): they caution that, due to the significant number of spurious sources in the low-probability catalog, it should NOT be used to select X-ray sources or to increase the sample size of X-ray-selected objects. It can be of interest if the scientific goal requires one to EXCLUDE potential X-ray emitting objects from a sample with a high completeness, since, using this strategy, one accepts those objects that are excluded are not associated with an X-ray-emitting object. The low-probability source catalog (available at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J_MNRAS/446/911/">http://cdsarc.u-strasbg.fr/ftp/cats/J_MNRAS/446/911/</a> as the files lowpscat.dat.gz and lowpscat.fits) has a lower maximum likelihood threshold than the main source catalog (an internal threshold of ML = 5, corresponding to ML<sub>empir</sub> ~9.5). This catalog contains 626 detected sources, of which 506 are located within the deep Subaru imaging region. Based on their simulated data, the authors conclude that 19% of all the low-probability source catalog entries are false detections. Considering only the deep Subaru imaging area the spurious source fraction drops to 15%. When using information from this catalog, please cite the reference paper: Krumpe et al. (2015, MNRAS, 446, 911). This table was created by the HEASARC in August 2015 based on CDS table J/MNRAS/446/911 files mainscat.dat, the main source catalog. 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/arcquincxo
- Title:
- Arches and Quintuplet Clusters Chandra X-Ray Point Source Catalog
- Short Name:
- ARCQUINCXO
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Galactic centre (GC) provides a unique laboratory for a detailed examination of the interplay between massive star formation and the nuclear environment of our Galaxy. Here are presented some of the results from a 100-ks Chandra Advanced CCD Imaging Spectrometer (ACIS) observation of the Arches and Quintuplet star clusters in the form of a catalog of 244 point-like X-ray sources detected in the observation. The deep Chandra ACIS-I observation (Obs. ID: 4500) was carried out on 2004 June 9. The Arches cluster was placed about 1-arcmin away from the aim point to minimize the effect of the CCD gaps on mapping the extended X-ray emission around the cluster. This table was created by the HEASARC in July 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/371/38">CDS Catalog J/MNRAS/371/38</a> file table1.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/acceptcat
- Title:
- Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) Catalog
- Short Name:
- ACCEPTCAT
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table, the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT) Catalog, contains the radial entropy profiles of the intracluster medium (ICM) for a collection of 239 clusters taken from the Chandra X-ray Observatory's Data Archive. Entropy is of great interest because it controls ICM global properties and records the thermal history of a cluster. The authors find that most ICM entropy profiles are well fitted by a model which is a power law at large radii and approaches a constant value at small radii: K(r) = K<sub>0</sub> + K<sub>100</sub> (r/100 kpc)<sup>alpha</sup>, where K<sub>0</sub> quantifies the typical excess of core entropy above the best-fitting power law found at larger radii. The authors also show that the K<sub>0</sub> distributions of both the full archival sample and the primary Highest X-Ray Flux Galaxy Cluster Sample of Reiprich (2001, Ph.D. thesis) are bimodal with a distinct gap between K<sub>0</sub> ~ 30 - 50 keV cm<sup>2</sup> and population peaks at K<sub>0</sub> ~ 15 keV cm<sup>2</sup> and K<sub>0</sub> ~ 150 keV cm<sup>2</sup>. The effects of point-spread function smearing and angular resolution on best-fit K<sub>0</sub> values are investigated using mock Chandra observations and degraded entropy profiles, respectively. The authors find that neither of these effects is sufficient to explain the entropy-profile flattening they measure at small radii. The influence of profile curvature and the number of radial bins on the best-fit K<sub>0</sub> is also considered, and they find no indication that K<sub>0</sub> is significantly impacted by either. All data and results associated with this work are publicly available via the project web site <a href="http://www.pa.msu.edu/astro/MC2/accept/">http://www.pa.msu.edu/astro/MC2/accept/</a>. The sample is collected from observations taken with the Chandra X-ray Observatory and which were publicly available in the CDA (Chandra Data Archive) as of 2008 August. This table was created by the HEASARC in January 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/182/12">CDS Catalog J/ApJS/182/12</a> files table1.dat and table5.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/bmwchancat
- Title:
- Brera Multi-scale Wavelet Chandra Source Catalog
- Short Name:
- BMWCHANCAT
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the BMW-Chandra source catalog drawn from essentially all Chandra ACIS-I pointed observations with an exposure time in excess of 10 ks that were public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999ApJ...524..414) and Campana et al. (1999ApJ...524..423C), which can characterize both point-like and extended sources, the authors identified 21325 sources. Among them, 16758 are serendipitous, i.e. not associated with the targets of the pointings, and do not require a non-automated analysis. This makes this catalog the largest compilation of Chandra sources as of the date of publication of this catalog (August 2008). The 0.5 - 10 keV absorption corrected fluxes of these sources range from ~3 x 10<sup>-16</sup> to 9 x 10<sup>-12</sup> erg/cm<sup>2</sup>/s with a median of 7 x 10<sup>-15</sup> erg/cm<sup>2</sup>/s. The catalog consists of count rates and relative errors in three energy bands (total, 0.5 - 7 keV; soft, 0.5 - 2 keV; and hard, 2 - 7 keV), and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate of the extension of the source. The authors include information drawn from the headers of the original files, as well, and extracted source counts in four additional energy bands, SB1 (0.5 - 1 keV), SB2 (1 - 2 keV), HB1 (2 - 4 keV), and HB2 (4 - 7 keV). They computed the sky coverage for the full catalog and for a subset at high Galactic latitude (|b| > 20 degrees). The complete catalog provides a sky coverage in the soft band (0.5 - 2 keV, S/N = 3) of ~8 deg<sup>2</sup> at a limiting flux of 10<sup>-13</sup> erg/cm<sup>2</sup>/s, and ~2 deg<sup>2</sup> at a limiting flux of ~10<sup>-15</sup> erg/cm<sup>2</sup>/s. The total numbers of matches with the FIRST, IRASPSC, 2MASS, and GSC2 catalogs obtained after a closest-distance selection are 13, 87, 6700, and 4485, respectively. This table was created by the HEASARC in September 2008 based on the CDS table J/A+A/488/1221 file catalog.dat. The catalog version is BMC 1.0.1F. All sources in this version of the catalog were from observations in POINTING and TIMED ACIS read modes. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cyder
- Title:
- Calan-Yale Deep Extragalactic Research Survey X-Ray Source Catalog
- Short Name:
- CYDER
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The main goal of the Calan-Yale Deep Extragalactic Research (CYDER) Survey X-ray survey is to study serendipitous X-ray sources detected by Chandra in an intermediate flux range (10<sup>-15</sup> to 10<sup>-12</sup> ergs/s) that comprises most of the X-ray background. A total of 267 X-ray sources spread over five archived fields were detected. The log N - log S distribution obtained for this sample is consistent with the results of other surveys. Deep V and I images were taken of these fields in order to calculate X-ray-to-optical flux ratios. Identifications and redshifts were obtained for 106 sources using optical spectroscopy from 8 m class telescopes to reach the optically faintest sources, to the same level as deeper X-ray fields like the Chandra Deep Fields, showing that the nature of sources detected depends mostly on the optical limit for spectroscopy. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/621/104, file table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/candelscxo
- Title:
- CANDELS H-Band Selected Chandra Source Catalog
- Short Name:
- CANDELSCXO
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Improving the capabilities of detecting faint X-ray sources is fundamental to increase the statistics on faint high-z AGN and star-forming galaxies. The authors performed a simultaneous maximum likelihood point-spread function (PSF) fit in the 0.5-2 keV and 2-7 keV energy bands of the 4 Ms Chandra Deep Field South (CDFS) data at the position of the 34,930 CANDELS H-band selected galaxies. For each detected source, they provide X-ray photometry and optical counterpart validation. The authors validated this technique by means of a ray-tracing simulation, and detected a total of 698 X-ray point-sources with a likelihood L > 4.98 (i.e.> 2.7sigma). They show that the prior knowledge of a deep sample of Optical-NIR galaxies leads to a significant increase of the detection of faint (i.e. ~ 10<sup>-17</sup> erg s<sup>-1</sup> cm<sup>-2</sup> in the 0.5-2 keV band) sources with respect to "blind" X-ray detections. By including previous catalogs, this work increases the total number of X-ray sources detected in the 4 Ms CDFS, CANDELS area to 793, which represents the largest sample of extremely faint X-ray sources assembled to date. These results suggest that a large fraction of the optical counterparts of our X-ray sources determined by likelihood ratio actually coincides with the priors used for the source detection. Most of the newly detected sources are likely star-forming galaxies or faint absorbed AGN. The authors identified a few sources with putative photometric redshift z > 4. Despite the low number statistics, this sample significantly increases the number of X-ray selected candidate high-z AGN. The 4-Ms CDFS consists of 23 observations described in Table 1 of Luo et al. (2008, ApJS, 179, 19) plus 31 other pointings described in Xue et al. (2011, ApJS, 195, 10, hereafter X11) for a total exposure of ~4 Ms. For the purpose of this paper, the authors employed only observations taken with a focal temperature of <= -120 C, since at higher temperatures the background cannot be modeled with their technique. This table was created by the HEASARC in July 2016 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/823/95">CDS Catalog J/ApJ/823/95</a> file catalog.dat. 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/carinaclas
- Title:
- Carina Nebula Chandra X-Ray Point Source Classes
- Short Name:
- CARINACLAS
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Chandra Carina Complex Project (CCCP) provides a sensitive X-ray survey of a nearby starburst region over > 1 deg<sup>2</sup> in extent. Thousands of faint X-ray sources are found, many concentrated into rich young stellar clusters. However, significant contamination from unrelated Galactic and extragalactic sources is present in the X-ray catalog. In their paper, the authors describe the use of a naive Bayes classifier to assign membership probabilities to individual sources, based on source location, X-ray properties, and visual/infrared properties. For the particular membership decision rule adopted, 75% of CCCP sources are classified as members, 11% are classified as contaminants, and 14% remain unclassified. The resulting sample of stars likely to be Carina members is used in several other studies, which appear in the special issue of Astrophysical Journal Supplement (Volume 194, May 2011 Issue) which was devoted to the CCCP. This table was created by the HEASARC in June 2011 based on the electronic version of Table 5 from the reference paper which was obtained from the ApJS web site. In the input source table, the names were truncated by 3 characters from their complete version. The HEASARC corrected these names, and also obtained the Chandra source positions, using the electronic version of Table 2 from the companion paper (Broos et al. 2011, ApJS, 194, 2: available as the HEASARC Browse table CARINACXO), also obtained from the ApJS web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/cargm31cxo
- Title:
- Carina Nebula Gum 31 Chandra X-Ray Point Source Catalog
- Short Name:
- CARGM31CXO
- Date:
- 11 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Gum 31 is a prominent, but still rather poorly studied, HII region around the stellar cluster NGC 3324 at the northwestern periphery of the Carina nebula complex. The aim of the authors aim was to reveal and characterize the young stellar population in Gum 31. An X-ray survey is the only efficient way to identify young stars in this region, which has extremely high galactic field-star contamination, that can avoid the strong biases of infrared-excess-selected samples of disk-bearing young stars. The authors used the Chandra observatory to perform a deep (70 ks) X-ray observation of the Gum 31 region and detected 679 X-ray point sources. This extends and complements the X-ray survey of the central Carina nebula regions performed in the Chandra Carina Complex Project (CCCP, available in the HEASARC database system as the CARINACXO table). Using deep near-infrared images from their recent VISTA survey of the Carina nebula complex, their comprehensive Spitzer point-source catalog, and optical archive data, the authors identify counterparts for 75% of these X-ray sources. The aimpoint of the ACIS-I observation was set to be RA(J2000) = 10<sup>h</sup> 37<sup>m</sup> 36.6<sup>s</sup>, Dec(J2000) = -58<sup>o</sup> 41' 18". This position is close to the center of the H II region, and allows both the stellar cluster NGC 3324 and the cluster G286.38-0.26 to be in the inner parts of the field-of-view, where the point-spread function is still very good. The pointing roll angle (i.e., the orientation of the detector with respect to the celestial north direction) was 138.35<sup>o</sup>. The ACIS field-of-view is just wide enough to cover the full spatial extent of the optically bright Gum 31 H II region and some parts of the surrounding dust shell (see Fig. 1 of the reference paper). The ACIS-I field of view is 17' x 17', which corresponds to 11.3 p x 11.3 pc at the Gum 31 distance of 2.3 kpc). The total net exposure time of the observation was 68,909s (19.14 h). The details of the source detection procedures are described in Section 21. of the reference paper. The final X-ray catalog contains 679 individual point sources. The number of extracted counts ranges from 3 for the faintest sources, up to 920 for the strongest source, while the median value is 11 counts. This table contains the basic X-ray properties and near- and mid-infrared photometry of the X-ray sources detected in the Gum 31 field. The details of the IR matching to the X-ray sources are given in Sections 4.1, 4.2 and 4.3 of the reference paper. This table was created by the HEASARC in May 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/564/A120">CDS Catalog J/A+A/564/A120</a> files table1.dat and table3.dat. This is a service provided by NASA HEASARC .
