This table is the Chandra Deep Field North 1-Megasecond Catalog. It lists point sources detected in an extremely deep X-ray survey (1 Ms) of the Hubble Deep Field North (HDF-N) and its environs (~450 square arcminutes) which has been performed with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. This is one of the two deepest X-ray surveys ever performed; for point sources near the aim point, it reaches 0.5 - 2.0 keV and 2 - 8 keV flux limits of ~3 x 10^-17 and ~2 x 10^-16 ergs cm-2 s-1, respectively. 370 distinct point sources have been detected: 360 in the full (0.5 - 8.0 keV) band, 325 in the soft (0.5 - 2.0 keV) band, 265 in the hard (2 - 8 keV) band, and 145 in the ultrahard (4 - 8 keV) band. Source positions are accurate to within 0.6 - 1.7 arcseconds (at ~90% confidence), depending mainly on the off-axis angle. Source densities of 7100 (+1100, -940) deg^-2 (at 4.2 x 10^-17 ergs cm^-2 s^-1) and 4200 (+670, -580) deg^-2 (at 3.8 x 10^-16 ergs cm^-2 s^-1) are observed in the soft and hard bands, respectively. This online catalog was created by the HEASARC in March 2002 based on a machine-readable version of Table 3 of Brandt et al. (2001) that was obtained from the Astronomical Journal website. This is a service provided by NASA HEASARC .

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_s <~ 23^m) 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 arcmin² region of ~1.9 x 10^-17, 6.4 x 10^-18, and 2.7 x 10^-17 erg cm^-2 s^-1 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^-2, and 47% +/- 4% of these sources are AGNs (~23,900 deg^-2). The authors adopted a binomial no-source probability value, P_B < 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_B 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_B < 0.1 are associated with bright, K_s <= 23^m, 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_H,Gal = 8.8 * 10¹⁹ cm^-2 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 H₀ = 67.8 km s^-1 Mpc^-1, Omega_M = 0.308, and Omega_Lambda = 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

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 arcmin². It contains 740 X-ray sources that are detected with wavdetect at a false-positive probability threshold of 10^-5 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^-5, 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^-2 and 6900 (+1100,-900) deg^-2, 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^-1 pixel^-1 (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^-17, 9.1 x 10^-18, and 5.5 x 10^-17 erg cm^-2 s^-1 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 .

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 arcmin² and reaches on-axis sensitivity limits of ~1.9 x 10^-17 and ~1.3 x 10^-16 erg cm^-2 s^-1 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^-1 pixel^-1, 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^-16 erg cm^-2 s^-1, while the CDF-S number counts are up to ~25% smaller than those for the CDF-N at fluxes below ~2 x 10^-16 erg cm^-2 s^-1 in the soft band and ~2 x 10^-15 erg cm^-2 s^-1 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 .

The Extended Chandra Deep Field-South (ECDFS) survey consists of four Chandra X-Ray Observatory (CXO) ACIS-I pointings and covers ~1100 arcmin² (~0.3 deg²) centered on the original CDF-S field to a depth of approximately 228 ks. This is the largest Chandra survey ever conducted at such depth, and only one XMM-Newton survey reaches a lower flux limit in the hard 2.0-8.0 keV band. The authors detect 651 unique sources: 587 using a conservative source-detection threshold (identified by source_type = 'P' for primary source) and 64 (identified by source_type = 'S' for secondary source) using a lower source-detection threshold. These are combined in this HEASARC representation but were presented as two separate catalogs (Table 4 contained the primary sources, and Table 5 the secondary sources) in the original reference paper. Of the 651 total sources, 561 are detected in the full 0.5-8.0 keV band, 529 in the soft 0.5-2.0 keV band, and 335 in the hard 2.0-8.0 keV band. For point sources near the aim point, the limiting fluxes are approximately 1.7 x 10^-16 and 3.9 x 10^-16 ergs/cm²/s in the 0.5-2.0 and 2.0-8.0 keV bands, respectively. In their paper, the authors present the differential and cumulative flux distributions, which are in good agreement with the number counts from previous deep X-ray surveys and with the predictions from an active galactic nucleus (AGN) population synthesis model that can explain the X-ray background. In general, fainter sources have harder X-ray spectra, consistent with the hypothesis that these sources are mainly obscured AGNs. All nine observations of the ECDFS survey field were conducted with the Advanced CCD Imaging Spectrometer (ACIS) on board Chandra as part of the approved guest observer program in Cycle 5. Notice that Lehmer et al. (2005, ApJS, 161, 21) conducted a somewhat different analysis on these same data and obtained similar, but not identical results, e.g., Lehmer et al. found 809 total X-ray sources compared to 651 in the present table. This table was created by the HEASARC in April 2009 based on the electronic versions of Tables 4 and 5 from the paper which were obtained from the CDS (their catalog J/AJ/131/2373 files table4.dat and table5.dat). This is a service provided by NASA HEASARC .

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 R_AB < 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. 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. This is a service provided by NASA HEASARC .

The authors of this table have obtained a series of deep X-ray images of the nearby (4.61 Mpc) galaxy M 83 using Chandra, with a total exposure of 729 ks. Combining the new data with earlier archival observations totaling 61 ks, they find 378 point sources within the D₂₅ contour of the galaxy. The authors find 80 more sources, mostly background active galactic nuclei (AGNs), outside of the D₂₅ contour. Of the X-ray sources, 47 have been detected in a new radio survey of M 83 obtained using the Australia Telescope Compact Array (ATCA). Of the X-ray sources, at least 87 seem likely to be supernova remnants (SNRs), based on a combination of their properties in X-rays and at other wavelengths. The authors attempt to classify the point source population of M 83 through a combination of spectral and temporal analysis. As part of this effort, in the reference paper they carry out an initial spectral analysis of the 29 brightest X-ray sources. The soft X-ray sources in the disk, many of which are SNRs, are associated with the spiral arms, while the harder X-ray sources, mostly X-ray binaries (XRBs), do not appear to be. After eliminating AGNs, foreground stars, and identified SNRs from the sample, the authors construct the cumulative luminosity function (CLF) of XRBs brighter than 8 x 10³⁵ erg s^-1. Despite M 83's relatively high star formation rate, the CLF indicates that most of the XRBs in the disk are low mass X-ray binaries (XRBs). The X-ray observations of M 83 in this survey were all carried out with the ACIS-S in order to maximize the sensitivity to soft X-ray sources, such as SNRs, and to diffuse emission. The nucleus of M 83 was centered in the field of the back-illuminated S3 chip to provide reasonably uniform coverage of M 83. In addition to the S3 chip, data were also obtained from chips S1, S2, S4, I2, and I3. All of the observations were made in the "very faint" mode to optimize background subtraction. Observations were spaced over a period of one year from 2010 December to 2011 December, as indicated in Table 1 of the reference paper. The only difference among observations was the roll orientation of the spacecraft and the differing exposure times. All of the observations were nominal, and yielded a total of 729 ks of useful data. In order to maximize their sensitivity and more importantly to improve their ability to identify time variable sources, the authors included in their analysis earlier Chandra observations of M 83 in 2000 and 2001 totaling 61 ks which were obtained by G. Rieke (Prop ID. 1600489) and by A. Prestwich (Prop ID. 267005758). These data were obtained in a very similar manner to that of the present survey, and increased the total exposure to 790 ks. The authors used ACIS EXTRACT (AE) to derive net count rates from the sources in various energy bands: 0.35 - 8.0 keV (total or T), 0.35 - 1.1 keV (soft or S), 1.1 - 2.6 keV (medium or M), 2.6 - 8.0 keV (hard or H), 0.5 - 2.0 keV ("normal" soft band) and 2.0 - 8.0 keV ("normal" hard band). Their choice of these bands was based on a variety of overlapping goals. The broad 0.35 - 8.0 keV band samples the full energy range accessible to Chandra observations. The three bands S, M and H provide energy ranges intended to classify sources on the basis of their hardness ratios. The boundary at 1.1 keV, in particular, is just above the region containing strong features due to Ne and Fe seen in the spectra of most SNRs. The 0.5 - 2.0 keV and 2.0 - 8.0 keV bands are needed because number counts of active galactic nuclei (AGNs) and of X-ray binary populations are normally carried out in these bands and because the 0.5 - 2.0 keV band, encompassing the peak of the response curve, provides better statistics for some purposes than S+M. The AE count rates were used to establish which of the sources in the candidate list were statistically valid. The authors retained any source that had a probability-of-no-source < 5 x

The ACIS instrument on board the Chandra X-Ray Observatory has been used to carry out the first systematic study of low-mass X-ray binaries (LMXBs) in M 87 (NGC 4486), the giant elliptical galaxy near the dynamical center of the Virgo Cluster. These images - with a total exposure time of 154 ks - are the deepest X-ray observations obtained as of 2004 of M 87. The authors identified 174 X-ray point sources, (contained in this Browse table) of which ~ 150 are likely LMXBs. This LMXB catalog was combined with deep F475W and F850LP images taken with ACS on the Hubble Space Telescope (HST) (as part of the ACS Virgo Cluster Survey) to examine the connection between LMXBs and globular clusters in M87. Of the 1688 globular clusters in the authors' catalog, a fraction f_X = 3.6% +/- 0.5% contain an LMXB. M 87 (NGC 4486) was observed with the Chandra Advanced CCD Imaging Spectrometer (ACIS) for 121 ks on 2002 July 5-6. In this table, only the S3 chip data are used. The data were processed following the CIAO data reduction threads, including a correction for charge transfer inefficiency (CTI). In addition, the authors used 38 ks of archival ACIS observations of M 87 taken on 2000 July 29. These data were processed in a fashion similar to the 2002 July data, except that no CTI correction was possible because the data were telemetered in graded mode. All reductions were carried out with CIAO, version 2.3, coupled with CALDB, version 2.21. In order to combine the event files into a single image for point-source detection, the authors obtained relative offsets by matching the celestial coordinates of two X-ray point sources. The relative offset was ~ 0.5". The total exposure time of the co-added image, excluding four background flares totaling ~ 2.5 ks, was 154 ks. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/613/279, file table1.dat. This is a service provided by NASA HEASARC .