The NGC 2516 Chandra X-Ray Point Source Catalog is the result of a comprehensive study of the Chandra X-ray observations of the young open star cluster NGC 2516. The authors have analyzed eight individual Chandra observations, comprising 5 ACIS and 3 HRC-I observations. They have combined these datasets to achieve the greatest sensitivity, reaching down to a threshold level of log f_X = -14.56 (erg/s/cm²), or log L_X = 28.69 (erg/s) at the 387 pc distance of NGC 2516. Out of 284 X-ray sources detected, 155 are identified with photometric cluster members, with very little ambiguity, another 60 with non-members. There are 4 X-ray sources with two possible optical identifications (one cluster member and one nonmember for each), with no obvious choice between the two candidates. These 4 X-ray sources are listed in this Browse table twice, one for each optical counterpart, hence there are (284 + 4 =) 288 entries. There remain 73 X-ray sources without an optical identification with the authors' optical catalog stars. This Browse table was created by the HEASARC in December 2006, based on CDS table J/ApJ/588/1009, files table4.dat and table5.dat. This is a service provided by NASA HEASARC .

This table contains a comprehensive X-ray point source catalog of the galaxy NGC 2403, an outlying member of the M 81 group of galaxies, as part of the Chandra Local Volume Survey. The combined archival observations of this galaxy have an effective exposure time of 190 ks. When combined with the catalogs of sources in NGC 55 and NGC 4214 given in this same reference paper, and the authors' previously published catalogs for NGC 300 (Binder et al. 2012, ApJ, 758, 15) and NGC 404 (Binder et al. 2013, ApJ, 763, 128), the CLVS contains 629 high-significance X-ray sources total down to a limiting unabsorbed luminosity of ~ 5 x 10³⁵ erg s^-1 in the 0.35-8.0 keV band in each of the five galaxies. In the reference paper, the authors present X-ray hardness ratios, spectral analysis, radial source distributions, and an analysis of the temporal variability for the X-ray sources detected at high significance. To constrain the nature of each X-ray source, they carried out cross-correlations with multi-wavelength data sets. They searched overlapping Hubble Space Telescope observations for optical counterparts to their X-ray detections to provide preliminary classifications for each X-ray source as a likely X-ray binary, background active galactic nucleus, supernova remnant, or foreground star. The authors utilized archival X-ray observations: NGC 2403 was observed by the Chandra X-Ray Observatory using the ACIS-S array on five occasions for a total of 190 ks:

 Obs. ID Date Eff. Exposure time (ks) 2014 2001 Apr 17 35 4627 2004 Aug 09 31 4628 2004 Aug 23 42 4629 2004 Oct 03 40 4630 2004 Dec 22 42 

The iterative source detection strategy that was used is described in Section 2.3 of Binder et al. (2012, ApJ, 758, 15). ACIS-Extract (AE) was run a final time on the source list that was produces after an initial run of wavdetect followed by several iterations of AE, and the Poisson probability of not being a source (pns) value was computed in each of the following nine energy bands: 0.5 - 8.0, 0.5 - 2.0, 2.0 - 8.0, 0.5 - 1.0, 1.0 - 2.0, 2.0 - 4.0, 4.0 - 8.0, 0.35 - 1.0 or 0.35 - 8.0 keV. To be included in the final NGC 2403 catalog, a source was required to have a pns value less than 4 x 10^-6 in any of the nine energy bands. The final CLVS source catalog for NGC 2403 contains 190 sources. This table was created by the HEASARC in September 2015 based on machine-readable versions of those parts of Table 5 and 8 from the reference paper which pertained to the 190 high-significance (pns < 4 x 10^-6) X-ray sources which were detected in NGC 2403. It does not include the 108 lower-significance sources in NGC 2403 which had 4 x 10^-6 < pns < 1.0 x 10^-3, some of which are likely to be genuine X-ray sources. This is a service provided by NASA HEASARC .

This table contains the point source catalog based on the first high spatial resolution X-ray study of NGC 2244, the 2 Myr old stellar cluster in the Rosette Nebula, using Chandra. Over 900 X-ray sources are detected within 20 arcminutes of the cluster central position (J2000.0 RA and Dec of 6 31 59.9, +4 55 36); 77% of these X-ray sources have optical or FLAMINGOS NIR stellar counterparts and are mostly previously uncataloged young cluster members. The X-ray-selected population is estimated to be nearly complete between 0.5 and 3 M_solar. A number of further results emerge from the analysis: (1) The X-ray luminosity function (XLF) and the associated K-band LF indicate a normal Salpeter IMF for NGC 2244. This is inconsistent with the top-heavy IMF reported from earlier optical studies that lacked a good census of < 4 M_solar stars. By comparing the NGC 2244 and Orion Nebula Cluster XLFs, the authors estimate a total population of ~2000 stars in NGC 2244. (2) The spatial distribution of X-ray stars is strongly concentrated around the central O5 star, HD 46150. The other early O star, HD 46223, has few companions. The cluster's stellar radial density profile shows two distinctive structures: a power-law cusp around HD 46150 that extends to ~0.7 pc, surrounded by an isothermal sphere extending out to 4 pc with core radius 1.2 pc. This double structure, combined with the absence of mass segregation, indicates that this 2 Myr old cluster is not in dynamical equilibrium. (3) The fraction of X-ray-selected cluster members with K-band excesses caused by inner protoplanetary disks is 6%, slightly lower than the 10% disk fraction estimated from the FLAMINGOS study based on the NIR-selected sample. (4) X-ray luminosities for 24 stars earlier than B4 confirm the long-standing log (L_X/L_bol) ~ -7 relation. The Rosette OB X-ray spectra are soft and consistent with the standard model of small-scale shocks in the inner wind of a single massive star. This table was created by the HEASARC in July 2008 based on electronic versions of Tables 2, 3, 4, 5 and 6 of the reference paper which were obtained from the electronic ApJ web site. This is a service provided by NASA HEASARC .

The authors have obtained high spatial resolution Chandra X-ray images of the NGC 2237 young stellar cluster on the periphery of the Rosette Nebula. They detect 168 X-ray sources, 80% of which have stellar counterparts in USNO, Two Micron All Sky Survey, and deep FLAMINGOS images. These constitute the first census of the cluster members with 0.2 <~ M <~ 2 M_sun. Star locations in near-infrared color-magnitude diagrams indicate a cluster age of around 2 Myr with a visual extinction of 1 <~ AV <~ 3 at 1.4 kpc, the distance of the Rosette Nebula's main cluster NGC 2244. The authors derive the K-band luminosity function and the X-ray luminosity function of the cluster, which indicate a population of ~ 400-600 stars. The X-ray-selected sample shows a K-excess disk frequency of 13%. The young Class II counterparts are aligned in an arc ~3 pc long suggestive of a triggered formation process induced by the O stars in NGC 2244. The diskless Class III sources are more dispersed. Several X-ray emitting stars are located inside the molecular cloud and around gaseous pillars projecting from the cloud. These stars, together with a previously unreported optical outflow originating inside the cloud, indicate that star formation is continuing at a low level and the cluster is still growing. This X-ray view of young stars on the western side of the Rosette Nebula complements the authors' earlier studies of the central cluster NGC 2244 and the embedded clusters on the eastern side of the Nebula. The large-scale distribution of the clusters and molecular material is consistent with a scenario in which the rich central NGC 2244 cluster formed first, and its expanding H II region triggered the formation of the now-unobscured satellite clusters Rosette Molecular Cloud (RMC) XA and NGC 2237. A large swept-up shell of material around the H II region is now in a second phase of collect-and-collapse fragmentation, leading to the recent formation of subclusters. Other clusters deeper in the molecular cloud appear unaffected by the Rosette Nebula expansion. Some sources which have information from published catalogs are listed by their source_number value below, where for convenience, [OI81] = Ogura & Ishida (1981, PASJ, 33, 149), [MJD95] = Massey, Johnson, & Degioia-Eastwood (1995, ApJ, 454, 151) and [BC02] = Berghofer & Christian (2002, A&A, 384, 890):

 53 = [OI81] 14 = [MJD95] 104; spectral type B1V; pmRA=11.0 mas/yr, pmDE=-2.8 mas/yr; 54 = [OI81] 10 = [MJD95] 108; spectral type B2V; pmRA=-2.3 mas/yr, pmDE=-11.9 mas/yr; 61 = V539 Mon [OI81] 13 = [MJD95] 110; MSX6C G206.1821-02.3456; pmRA=2.8 mas/yr, pmDE=0.4 mas/yr; 71 = [OI81] 12 = [MJD95] 102; pmRA=6.8 mas/yr, pmDE=0.6 mas/yr; 128 = [OI81] 35 = [MJD95] 471; spectral type A2:; pmRA=-0.8 mas/yr, pmDE=3.6 mas/yr; 138 = [OI81] 36 = [MJD95] 497; spectral type B5; pmRA=6.5 mas/yr, pmDE=2.1 mas/yr; 141 = [MJD95] 498; pmRA=-3.0 mas/yr, pmDE=1.9 mas/yr; 149 = [BC02] 11; known X-ray source; log(Lx(ROSAT/PSPC))=31.01 erg/s; pmRA=0.6 mas/yr, pmDE=-12.6 mas/yr; 161 = [MJD95] 653; pmRA=-1.0 mas/yr, pmDE=-5.4 mas/yr 

This table was created by the HEASARC in July 2010 based on electronic versions of Tables 1, 2, 3 and 4 of the reference paper which were obtained from the electronic ApJ web site. To distinguish between the 130 X-ray sources in the primary sample (Table 1 of the reference paper) and the 38 X-ray sources in the tentative sample (Table 2 of the reference paper), the HEASARC has created a parameter called source_sample which is set to 'P' for the primary sources and to 'T' for the tentative sources. This is a service provided by NASA HEASARC .

This table contains the sources detected in a Chandra X-ray observation of the Galactic globular cluster NGC 2808, as well as the corresponding XMM-Newton data for those sources which have XMM-Newton X-ray counterparts. Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble Space Telescope far-ultraviolet observations, the authors aim to detect and identify the faint X-ray sources belonging to NGC 2808 in order to understand their role in the evolution of globular clusters. The authors classify the X-ray sources associated with the cluster by analysing their colors and variability. Previous observations with XMM-Newton and far-ultraviolet observations with Hubble are re-investigated to help identify the Chandra sources associated with the cluster. The authors compare their results to population synthesis models and observations of other Galactic globular clusters. NGC 2808 was observed with the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer-Imager (ACIS-I) on 2007 June 19-21 (28 months after the XMM-Newton observation referred to the reference paper) for two distinct exposures of 46 and 11 kiloseconds. The authors detect 113 sources, of which 16 fall inside the half-mass radius of NGC 2808 and are concentrated towards the cluster core. This table was created by the HEASARC in February 2009 based on the electronic version of Table 1 from the paper which was obtained from the CDS (their catalog J/A+A/490/641 file table1.dat). This is a service provided by NASA HEASARC .

This table contains the main X-ray source catalog for the Chandra monitoring observations of the 16.5-Mpc distant elliptical galaxy, NGC 4649. The galaxy has been observed with Chandra ACIS-S3 in six separate pointings, reaching a total exposure of 299 ks. There are 501 X-ray sources detected in the 0.3-8.0 keV band in the merged observation or in one of the six individual observations; 399 sources are located within the D₂₅ ellipse. The observed 0.3-8.0 keV luminosities of these 501 sources range from 9.3 x 10³⁶ erg s^-1 to 5.4 x 10³⁹ erg s^-1. The 90% detection completeness limit within the D₂₅ ellipse is 5.5 x 10³⁷ erg s^-1. Based on the surface density of background active galactic nuclei (AGNs) and the detection completeness, we expect ~ 45 background AGNs among the catalog sources (~ 15 within the D₂₅ ellipse). There are nine sources with luminosities greater than 10³⁹ erg s^-1, which are candidates for ultraluminous X-ray sources. The nuclear source of NGC 4649 is a low-luminosity AGN, with an intrinsic 2.0-8.0 keV X-ray luminosity of 1.5 x 10³⁸ erg s^-1. The X-ray colors suggest that the majority of the catalog sources are low-mass X-ray binaries (LMXBs). The authors find that 164 of the 501 X-ray sources show long-term variability, indicating that they are accreting compact objects, and discover four transient candidates and another four potential transients. They also identify 173 X-ray sources (141 within the D₂₅ ellipse) that are associated with globular clusters (GCs) based on Hubble Space Telescope and ground-based data; these LMXBs tend to be hosted by red GCs. Although NGC 4649 has a much larger population of X-ray sources than the structurally similar early-type galaxies, NGC 3379 and NGC 4278, the X-ray source properties are comparable in all three systems. This HEASARC table contains the main Chandra source catalog of the basic properties of the 501 X-ray detected sources (Table 3 in the reference paper which includes both sources detected in the merged X-ray image as well as a number only detected in the individual observations), and also the information on source counts, hardness ratios and soft and hard X-ray colors in the merged observation for the same 501 X-ray detected sources (Table 4 in the reference paper). It does not contain the information on source counts, hardness ratios and soft and hard X-ray colors for these same sources in the six individual observations that were contained in Tables 5 - 10 of the reference paper. This table was created by the HEASARC in March 2013 based on the electronic version of Tables 3 and 4 from the reference paper which were obtained from the ApJS website.. This is a service provided by NASA HEASARC .

This table contains a comprehensive X-ray point source catalog of the SB(s)m galaxy NGC 55, a member of the nearby Sculptor group of galaxies, as part of the Chandra Local Volume Survey. The combined archival observations of this galaxy have an effective exposure time of 56.5 ks. When combined with the catalogs of sources in NGC 2403 and NGC 4214 given in this same reference paper, and the authors' previously published catalogs for NGC 300 (Binder et al. 2012, ApJ, 758, 15) and NGC 404 (Binder et al. 2013, ApJ, 763, 128), the CLVS contains 629 high-significance X-ray sources total down to a limiting unabsorbed luminosity of ~ 5 x 10³⁵ erg s^-1 in the 0.35-8.0 keV band in each of the five galaxies. In the reference paper, the authors present X-ray hardness ratios, spectral analysis, radial source distributions, and an analysis of the temporal variability for the X-ray sources detected at high significance. To constrain the nature of each X-ray source, they carried out cross-correlations with multi-wavelength data sets. They searched overlapping Hubble Space Telescope observations for optical counterparts to their X-ray detections to provide preliminary classifications for each X-ray source as a likely X-ray binary, background active galactic nucleus, supernova remnant, or foreground star. The authors utilized archival X-ray observations: NGC 55 was observed by the Chandra X-Ray Observatory on 2001 September 11 for 47 ks using the ACIS-I array (Obs. ID 2255), and on 2004 June 29 for 9.5 ks using the ACIS-I array (Obs. ID 4744). The iterative source detection strategy that was used is described in Section 2.3 of Binder et al. (2012, ApJ, 758, 15). ACIS-Extract (AE) was run a final time on the source list that was produces after an initial run of wavdetect followed by several iterations of AE, and the Poisson probability of not being a source (pns) value was computed in each of the following nine energy bands: 0.5 - 8.0, 0.5 - 2.0, 2.0 - 8.0, 0.5 - 1.0, 1.0 - 2.0, 2.0 - 4.0, 4.0 - 8.0, 0.35 - 1.0 or 0.35 - 8.0 keV. To be included in the final NGC 55 catalog, a source was required to have a pns value less than 4 x 10^-6 in any of the nine energy bands. The final CLVS source catalog for NGC 55 contains 154 sources. This table was created by the HEASARC in September 2015 based on machine-readable versions of those parts of Table 5 and 8 from the reference paper which pertained to the 154 high-significance (pns < 4 x 10^-6) X-ray sources which were detected in NGC 55. It does not include the 76 lower-significance sources in NGC 55 which had 4 x 10^-6 < pns < 1.0 x 10^-3, some of which are likely to be genuine X-ray sources. This is a service provided by NASA HEASARC .

This table contains a comprehensive X-ray point source catalog of the IAB(s)m galaxy NGC 4214 similar to the LMC, one of the nearest examples of a starburst galaxy with a substantial population of Wolf-Rayet stars, as part of the Chandra Local Volume Survey. The combined archival observations of this galaxy have an effective exposure time of 79 ks. When combined with the catalogs of sources in NGC 55 and NGC 2403 given in this same reference paper, and the authors' previously published catalogs for NGC 300 (Binder et al. 2012, ApJ, 758, 15) and NGC 404 (Binder et al. 2013, ApJ, 763, 128), the CLVS contains 629 high-significance X-ray sources total down to a limiting unabsorbed luminosity of ~ 5 x 10³⁵ erg s^-1 in the 0.35-8.0 keV band in each of the five galaxies. In the reference paper, the authors present X-ray hardness ratios, spectral analysis, radial source distributions, and an analysis of the temporal variability for the X-ray sources detected at high significance. To constrain the nature of each X-ray source, they carried out cross-correlations with multi-wavelength data sets. They searched overlapping Hubble Space Telescope observations for optical counterparts to their X-ray detections to provide preliminary classifications for each X-ray source as a likely X-ray binary, background active galactic nucleus, supernova remnant, or foreground star. The authors utilized archival X-ray observations: NGC 4214 was observed by the Chandra X-Ray Observatory using the ACIS-S array on three occasions for a total of 79 ks:

 Obs. ID Date Eff. Exposure time (ks) 2030 2001 Oct 16 25 4743 2004 Apr 03 26 5197 2004 Jul 30 28 

The iterative source detection strategy that was used is described in Section 2.3 of Binder et al. (2012, ApJ, 758, 15). ACIS-Extract (AE) was run a final time on the source list that was produces after an initial run of wavdetect followed by several iterations of AE, and the Poisson probability of not being a source (pns) value was computed in each of the following nine energy bands: 0.5 - 8.0, 0.5 - 2.0, 2.0 - 8.0, 0.5 - 1.0, 1.0 - 2.0, 2.0 - 4.0, 4.0 - 8.0, 0.35 - 1.0 or 0.35 - 8.0 keV. To be included in the final NGC 4214 catalog, a source was required to have a pns value less than 4 x 10^-6 in any of the nine energy bands. The final CLVS source catalog for NGC 2403 contains 116 sources. This table was created by the HEASARC in September 2015 based on machine-readable versions of those parts of Table 5 and 8 from the reference paper which pertained to the 116 high-significance (pns < 4 x 10^-6) X-ray sources which were detected in NGC 4214. It does not include the 95 lower-significance sources in NGC 4214 which had 4 x 10^-6 < pns < 1.0 x 10^-3, some of which are likely to be genuine X-ray sources. This is a service provided by NASA HEASARC .