The Chandra data archive is a treasure trove for various studies, and in this study the author exploits this valuable resource to study the X-ray point source populations in nearby galaxies. By 2007 December 14, 383 galaxies within 40 Mpc with isophotal major axes above 1 arcminute had been observed by 626 public ACIS observations, most of which were for the first time analyzed by this survey to study the X-ray point sources. Uniform data analysis procedures were applied to the 626 ACIS observations and led to the detection of 28,099 point sources, which belong to 17,559 independent sources. These include 8700 sources observed twice or more and 1000 sources observed 10 times or more, providing a wealth of data to study the long-term variability of these X-ray sources. Cross-correlation of these sources with galaxy isophotes led to 8,519 sources within the D₂₅ isophotes of 351 galaxies, 3,305 sources between the D₂₅ and 2 * D₂₅ isophotes of 309 galaxies, and an additional 5,735 sources outside the 2 * D₂₅ isophotes of galaxies. This survey has produced a uniform catalog, by far the largest, of 11,824 X-ray point sources within 2 * D₂₅ isophotes of 380 galaxies. Contamination analysis using the log N-log S relation shows that 74% of the sources within the 2 * D₂₅ isophotes above 10³⁹ erg s^-1, 71% of the sources above 10³⁸ erg s^-1, 63% of the sources above 10³⁷ erg s^-1, and 56% of all sources are truly associated with the galaxies. Meticulous efforts have identified 234 X-ray sources with galactic nuclei of nearby galaxies. This archival survey leads to 300 ultraluminous X-ray sources (ULXs) with L_X in the 0.3-8 keV band >= 2 x 10³⁹ erg s^-1 within the D₂₅ isophotes, 179 ULXs between the D₂₅ and the 2 * D₂₅ isophotes, and a total of 479 ULXs within 188 host galaxies, with about 324 ULXs truly associated with the host galaxies based on the contamination analysis. About 4% of the sources exhibited at least one supersoft phase, and 70 sources are classified as ultraluminous supersoft sources with L_X (0.3-8 keV) >= 2 x 10³⁸ erg s^-1. With a uniform data set and good statistics, this survey enables future works on various topics, such as X-ray luminosity functions for the ordinary X-ray binary populations in different types of galaxies, and X-ray properties of galactic nuclei. This table contains the list of 17,559 'independent' X-ray point sources that was contained in table 4 of the reference paper. As the author notes in Section 5 of this paper, there are 341 sources projected within 2 galaxies with overlapping domains which are listed for both galaxies. The 5,735 sources lieing outside the 2* D₂₅ isophotes of the galaxies are also included in this table. For these sources, the X-ray luminosities are computed as if they were in a galaxy of that group, which may or may not be the case; thus, they may not be their 'true' luminosities, but are listed for the purposes of comparison. This table was created by the HEASARC in March 2011 based on the electronic version of Table 4 of the reference paper which was obtained from the Astrophysical Journal web site. 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 .

This table contains the Chandra X-ray point source catalogs for 9 Hickson Compact Groups (HCGs, 37 galaxies) at distances of 34 to 89 Mpc. The authors perform detailed X-ray point source detection and photometry and interpret the point source population by means of simulated hardness ratios. They thus estimate X-ray luminosities (L_X) for all sources, most of which are too weak for reliable spectral fitting. For all sources, they provide counts, count rates, power-law indices (Gamma), hardness ratios, and L_X, in the full (0.5-8.0 keV), soft (0.5-2.0 keV) and hard (2-8 keV) bands. In their paper, the authors use optical emission-line ratios from the literature to re-classify 24 galaxies as star-forming, accreting onto a supermassive black hole (AGNs), transition objects, or low-ionization nuclear emission regions. Two-thirds of their galaxies have nuclear X-ray sources with Swift/UVOT counterparts. Two nuclei have full-band X-ray luminosities >= 10⁴² erg s^-1, are strong multi-wavelength AGNs, and follow the known alpha_OX - nu L_nu(near-UV)_ correlation for strong AGNs. Otherwise, most nuclei are X-ray faint, consistent with either a low-luminosity AGN or a nuclear X-ray binary population, and fall into the 'non-AGN' locus in alpha_OX - nu L_nu(near-UV)_ space, which also hosts other normal galaxies. Each group was observed at the aim point of the back-illuminated S3 CCD of Chandra's Advanced CCD Imaging Spectrometer (ACIS), with the exception of HCG 90, which was observed with the ACIS-I array. The details of the 9 Chandra observations analyzed herein are given in Table 1 of the reference paper. The full details of the X-ray analysis and point source detection procedures are given in Section 3 of the reference paper. This table was created by the HEASARC in June 2014 based on electronic versions of Tables 2 and 3 from the reference paper which were obtained from the ApJS web site. 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 .

This table lists some of the properties of the discrete X-ray sources detected in the authors' monitoring program of the globular cluster (GC)-rich elliptical galaxy, NGC 4278, observed with Chandra ACIS-S in six separate pointings, resulting in a co-added exposure of 458 ks. From this deep observation, 236 sources have been detected within the region overlapped by all observations, 180 of which lie within the D₂₅ ellipse angular diameter of the galaxy. These 236 sources range in X-ray luminosity L_X from 3.5 x 10³⁶ erg s^-1 (with 3-sigma upper limit <= 1 x 10³⁷ erg s^-1) to ~2 x 10⁴⁰ erg s^-1, including the central nuclear source which has been classified as a LINER. From optical data, 39 X-ray sources have been determined to be coincident with a GC, these sources tend to have high X-ray luminosity, with 10 of these sources exhibiting L_X > 1 x 10³⁸ erg s^-1. From X-ray source photometry, it has been determined that the majority of the 236 point sources that have well-constrained colors have values that are consistent with typical low-mass X-ray binary spectra, with 29 of the sources expected to be background objects from the log N-log S relation. There are 103 sources in this population that exhibit long-term variability, indicating that they are accreting compact objects. Three of these sources have been identified as transient candidates, with a further three possible transients. Spectral variations have also been identified in the majority of the source population, where a diverse range of variability has been identified, indicating that there are many different source classes located within this galaxy. This HEASARC table contains the master source list (Table 3 of the reference paper) and the X-ray properties of the sources in the co-added observations (Table 4 of the reference paper), but not the X-ray properties of the sources in the 6 individual observations (Tables 5-10 of the reference paper). The details of the six individual pointings used in this study, e.g., the Chandra ObsIDs, dates, exposure times and cleaned exposure times, are given in Table 1 of the reference paper, and repeated here:

 Obs. No.OBSID Date Exposure (s) Cleaned Exposure (s) 1 4741 2005 Feb 3 37462.0 37264.5 2 7077 2006 Mar 16 110303.8 107736.7 3 7078 2006 Jul 25 51433.2 48076.2 4 7079 2006 Oct 24 105071.7 102504.6 5 7081 2007 Feb 20 110724.0 107564.5 6 7080 2007 Apr 20 55824.8 54837.5 Total Co-added 470819.5 457984.0 

Notes. The pointing OBSID 7181 was taken before OBSID 7080, so to maintain the time sequence of the exposures these observation numbers have been labeled as above in the reference paper. The details of the energy bands and X-ray colors used in this study are given in Table 2 of the reference paper, and repeated here:

 Band/Color Energy Range/Definition Broad (B) 0.3-8 keV Soft (S) 0.3-2.5 keV Hard (H) 2.5-8 keV Soft 1 (S1) 0.3-0.9 keV Soft 2 (S2) 0.9-2.5 keV Conventional broad (Bc) 0.5-8 keV Conventional soft (Sc) 0.5-2 keV Conventional hard (Hc) 2-8 keV Hardness ratio HR (Hc-Sc)/(Hc+Sc) X-ray color C21 -log(S2) + log(S1) = log(S1/S2) X-ray color C32 -log(H) + log(S2) = log(S2/H) 

This table was created by the HEASARC in April 2009 based on machine-readable versions of Tables 3 and 4 from the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .

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_XP 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_XP 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 .

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