- ID:
- ivo://nasa.heasarc/mystixmpcm
- Title:
- MassiveYoungStar-FormingComplexStdyinIR&X-Rays:MYStIXProbComplexMbrs
- Short Name:
- MYSTIXMPCM
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Massive Young Star-forming complex Study in Infrared and X-rays (MYStIX) project requires samples of young stars that are likely members of 20 nearby Galactic massive star-forming regions. Membership is inferred from statistical classification of X-ray sources, from detection of a robust infrared excess that is best explained by circumstellar dust in a disk or infalling envelope and from published spectral types that are unlikely to be found among field stars. This table contains the MYStIX membership lists, which total 31,549 probable complex members. In their reference paper, the authors describe in detail the statistical classification of X-ray sources via a "Naive Bayes Classifier". These membership lists provide the empirical foundation for subsequent MYStIX science studies. The MYStIX project, described by Feigelson et al. (2013, ApJS, 209, 26), seeks to identify and study samples of young stars in 20 nearby (0.4 < D < 3.6kpc) Galactic massive star-forming regions (MSFRs). These samples are derived using X-ray data from the Chandra X-ray Observatory, near-infrared (NIR) photometry from the United Kingdom InfraRed Telescope (UKIRT) and from the Two Micron All Sky Survey (2MASS), mid-infrared (MIR) photometry from the Spitzer Space Telescope, and from published spectroscopically-identified massive stars. The purpose of this study is to describe the authors' efforts to minimize contaminants in the MYStIX catalogs of young stars. They refer to these latter objects as the "MYStIX Probable Complex Members" or MPCMs. This table contains the combined MPCM catalog for all 20 of the MYStIX MSFRs. This MPCM catalog is the union of three sets of probable members identified by three different established methods for identifying young stars (see Feigelson et al. 2013, ApJS, 209, 26, Fig. 3). Most of the X-ray information on the MPCMs (with the exception of the X-ray luminosities and absorbing column densities obtained using XPHOT) was produced by the ACIS Extract (AE) software package (Broos et al. 2010, ApJ, 714, 1582 and 2012, Astrophysics Source Code Library, 1203.001). The AE software and User's Guide are available at <a href="http://www.astro.psu.edu/xray/acis/acis_analysis.html">http://www.astro.psu.edu/xray/acis/acis_analysis.html</a>. X-ray quantities using the 'fb' prefix are for the full or total energy band from 0.5 - 8.0 keV, those using the 'sb' prefix are for the soft band from 0.5 - 2.0 keV, and those using the 'hb' prefix are for the hard band from 2.0 - 8.0 keV. L. K. Townsley and P. S. Broos (2013, in preparation) and Kuhn et al. (2013, ApJS, 209, 27) identify a few very bright X-ray sources in each region that suffer from a type of instrumental non-linearity known as photon pile-up (<a href="http://cxc.harvard.edu/ciao/why/pileup_intro.html">http://cxc.harvard.edu/ciao/why/pileup_intro.html</a>); X-ray properties reported for those sources are biased and should be used with caution. This table was created by the HEASARC in February 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/209/32">CDS Catalog J/ApJS/209/32</a> file mpcm.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/mystixxray
- Title:
- MassiveYoungStar-FormingComplexStudyinIR&X-Rays:X-RaySourceCatalog
- Short Name:
- MYSTIXXRAY
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Massive Young Star-forming complex Study in Infrared and X-ray (MYStIX) uses data from the Chandra X-Ray Observatory to identify and characterize the young stellar populations in 20 Galactic (d < 4 kpc) massive star-forming regions. In this present study, the X-ray analysis for Chandra ACIS-I observations of 10 of the MYStIX fields is described, and a catalog of > 10,000 X-ray sources is presented in this table. In comparison to other published Chandra source lists for the same regions, the number of MYStIX-detected faint X-ray sources in a region is often doubled. While the higher catalog sensitivity increases the chance of false detections, it also increases the number of matches to infrared stars. X-ray emitting contaminants include foreground stars, background stars, and extragalactic sources. The X-ray properties of sources in these classes are discussed in the reference paper. The X-ray observations were made with the imaging array on the Advanced CCD Imaging Spectrometer (ACIS-I) on board the Chandra X-Ray Observatory. This array of four CCD detectors subtends 17' x 17' on the sky. The number of different Chandra pointings for each region, the total exposures for these pointings, and details of how the observations were taken are provided in Table 1 of the reference paper. Overall, 29 Chandra ObsIDs are included with typical integration times for a pointing of 40 - 100 ks, sufficient to detect most OB stars and lower-mass pre-main-sequence stars down to ~ 0.5 - 1 solar masses for the MYStIX regions. The 10 MYStIX MSFRs treated herein are listed in Table 2 of the reference paper. The data were acquired from the Chandra Data Archive from 2001 Jan to Mar 2008 for 10 MYStIX fields (the Flame Nebula, RCW 36, NGC 2264, the Rosette Nebula, the Lagoon Nebula, NGC 2362, DR 21, RCW 38, Trifid Nebula and NGC 1893). The X-ray photometry is from Broos et al. (2010, ApJ, 714, 1582; ACIS Extract); see also the CCCP, Broos et al. (2011, ApJS, 194, 2). The source significance quantities (fb_prob_no_src, sb_prob_no_src, hb_prob_no_src and prob_no_src_min) are computed using a subset of each source's extractions chosen to maximize significance (Broos et al. 2010, ApJ, 714, 1582, Section 6.2). The source position and positional uncertainty quantities are computed using a subset of each source's extractions chosen to minimize the position uncertainty (Broos et al. 2010, ApJ, 714, 1582, Sections 6.2 and 7.1). All other quantities are computed using a subset of each source's extractions chosen to balance the conflicting goals of minimizing photometric uncertainty and of avoiding photometric bias (Broos et al. 2010, ApJ, 714, 1582, Sections 6.2 and 7). The observed and absorption-corrected energy fluxes and their associated errors and the estimated hydrogen column densities and their uncertainties are derived using non-parametric procedures (XPHOT, Getman et al. 2010, ApJ, 708, 1760). XPHOT assumes the X-ray spectral shapes of young, low-mass stars, which come from coronal X-ray emission. XPHOT quantities will therefore be unreliable for high-mass stars, for which X-ray emission is associated with the stellar wind. This table was created by the HEASARC in January 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/209">CDS Catalog J/ApJS/209</a> 27 file xmystix.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m31cxo2
- Title:
- M 31 Bulge Chandra X-Ray Point Source Catalog
- Short Name:
- M31CXO2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors explore the population of X-ray point sources in the bulge of M 31 so as to contrast properties of various subpopulations, such as persistent and transient sources and primordial LMXBs and dynamically formed ones. Based on the data from 26 archival Chandra ACIS observations with aim-points within 10 arcminutes of the center of M 31 (J2000 coordinates of 00:42:44.31, +41:16:09.4), the authors study the source content and properties of various subpopulations of X-ray sources to a maximum distance of 12 arcminutes from the center of M 31. To a limiting luminosity of ~10<sup>35</sup> erg s<sup>-1</sup>, the authors find 263 X-ray point sources, with ~1/3 of these being background galaxies. A study of the spatial distribution and the luminosity function of the X-ray sources shows that the distribution of primordial LMXBs is consistent with the distribution of the K-band light and that their luminosity function flattens below ~10<sup>37</sup> erg s<sup>-1</sup> to the dN/dL ~ L<sup>-1</sup> law in agreement with the behavior found earlier for LMXBs in the Milky Way and in Cen A. Within a radius of 12 arcminutes, the luminosity function is independent of distance to the center of M 31, in contrast to earlier Chandra studies. The LMXBs located in globular clusters and within ~1 arcminute from the center of M 31 are presumably created via dynamical interactions. The dynamical origin of the r < 1 arcminute sources is strongly suggested by their radial distribution which follows the rho<sub>*</sub><sup>2</sup> profile rather than the K-band light distribution. Their luminosity function shows a prominent fall-off below log(L<sub>X</sub>) <~ 36.5. Although the statistics are insufficient to claim a genuine low-luminosity cut-off in the luminosity function, the best fit power-law with a slope of -0.6 +/- 0.2 is significantly flatter than the dN/dL ~ L<sup>-1</sup> law. The authors also searched for transients and found 28 sources that varied by a factor larger than 20. Their spatial distribution follows the distribution of the persistent LMXBs within the accuracy allowed by the limited number of transients. This HEASARC table was created in March 2010 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/468/49">CDS catalog J/A+A/468/49</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m31cfcxo
- Title:
- M 31 Central Field Chandra HRI X-Ray Point Source Catalog
- Short Name:
- M31CFCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The central field of the Andromeda galaxy (M 31) was monitored from 2006 to 2012 using the Chandra HRC-I detector (about 0.1 - 10 keV energy range) with the main aim of detecting X-rays from optical novae. The authors present a systematic analysis of all X-ray sources found in the 41 nova monitoring observations, along with 23 M 31 central field HRC-I observations available from the Chandra data archive starting in December 1999. Based on these observations, they studied the X-ray long-term variability of the source population and especially of the X-ray binaries in M31. The authors created a catalog of sources detected in the 64 available observations that adds up to a total exposure time of about 1 Ms. To study the variability, they developed a processing pipeline to derive long-term Chandra HRC-I light curves for each source over the 13 years of observations, and also searched for extended X-ray sources in the merged images. This table contains the point-source catalog of 318 X-ray sources with detailed long-term variability information, 28 of which are published for the first time. The spatial and temporal resolution of the catalog allows the authors to classify 115 X-ray binary candidates showing high X-ray variability or even outbursts, as well as 14 globular cluster X-ray binary candidates showing no significant variability. The analysis may suggest that outburst sources are less frequent in globular clusters than in the field of M 31. Seven supernova remnants (not included in the point-source catalog) were detected, one of which is a new candidate, and also the first X-rays from a known radio supernova remnant were resolved. In addition to 33 known optical nova/X-ray source correlations, the authors discovered one previously unknown super-soft X-ray outburst and several new nova candidates. A large sample of detailed long-term X-ray light curves of sources in the M31 central field has been obtained in this study (see Appendix B.1 of the reference paper), which helps in understanding the X-ray population of our neighboring spiral galaxy M 31. Based on all the available Chandra HRC-I observations (see Table A.1 in the reference paper for the complete list), a source catalog has been created (available in this HEASARC table) and the energy flux of each source in every individual observation derived (these are not available in this HEASARC table, but are obtainable at the CDS: for more details, see the files <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A%2BA/555/A65/ReadMe">https://cdsarc.cds.unistra.fr/ftp/cats/J/A%2BA/555/A65/ReadMe</a> and <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J_A%2BA/555/A65/table2.dat.gz">https://cdsarc.cds.unistra.fr/ftp/cats/J_A%2BA/555/A65/table2.dat.gz</a>). One thing to be aware of is that, in the latter file, upper limits are denoted by a '>' symbol rather than the more usual '<' symbol!). These fluxes were calculated assuming a generic power law spectrum and Galactic foreground absorption for each source. This table was created by the HEASARC in August 2013 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/555/A65">CDS catalog J/A+A/555/A65</a> files table1.dat and xcorr.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m31cxoxray
- Title:
- M 31 Central Region Chandra X-Ray Point Source Catalog
- Short Name:
- Chan/M31
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table countains the M 31 Central Region Catalog of Chandra X-Ray Point Sources. It is based on Chandra observations of the central region of M 31. By combining eight Chandra ACIS-I observations which were taken between 1999 and 2001, the authors have identified 204 X-ray sources within the central ~17'x17' region of M 31, with a detection limit of ~2x10<sup>35</sup> erg/s. Of these 204 X-ray sources, 22 are identified with globular clusters, two with supernova remnants, nine with planetary nebulae, and nine with supersoft sources. By comparing individual images, about 50% of the sources were found to be variable on timescales of months. The authors also found 13 transients, with light curves showing a variety of shapes. They also extracted the energy spectra of the 20 brightest sources; they can be well fitted by a single power law with a mean photon index of 1.8. The spectral shapes of 12 sources were variable, suggesting that they went through state changes. All sources in the catalog have S/N > 2.5 and only five have S/N < 3.0. The detection limit for the sources varies across the image due to the variation of exposure time, background, and instrumental PSF, and is highest near the edges, where the PSF broadens rapidly and the exposure time is lowest. Over the inner 4' of the field, the detection limit is 2.1 x 10<sup>-4</sup> ct/s, which is equivalent to an X-ray luminosity of about 2 x 10<sup>35</sup> erg/s. Additional information about optical identifications and cross-correlated ROSAT X-ray sources not provided in this HEASARC table is available in the published paper (Tables 4 and 5) and/or the CDS at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/577/738/">https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/577/738/</a> (table4.dat & table5.dat). This table was created by the HEASARC in October 2004 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/577/738/table2">CDS Catalog J/ApJ/577/738/table2</a>.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m33chase
- Title:
- M 33 Chandra ACIS Survey (ChASeM33) Final Source Catalog
- Short Name:
- M33CHASE
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the final source catalog of the Chandra ACIS Survey of M33 (ChASeM33). With a total exposure time of 1.4 Ms, ChASeM33 covers ~70% of the D<sub>25</sub> isophote (radial extent ~ 4.0 kpc) of M33 and provides the deepest, most complete, and detailed look at a spiral galaxy in X-rays. The source catalog includes 662 sources, reaches a limiting unabsorbed luminosity of ~2.4 x 10<sup>34</sup> erg s<sup>-1</sup> in the 0.35-8.0 keV energy band, and contains source positions, source net counts, fluxes and significances in several energy bands, and information on source variability. The analysis challenges posed by ChASeM33 and the techniques adopted to address these challenges are discussed. To constrain the nature of the detected X-ray source, hardness ratios were constructed and spectra were fit for 254 sources, follow-up Multiple Mirror Telescope (MMT) spectra of 116 sources were acquired, and cross-correlations with previous X-ray catalogs and other multi-wavelength data were generated. Based on this effort, 183 of the 662 ChASeM33 sources could be identified. Finally, in the reference paper, the luminosity function (LF) for the detected point sources as well as the one for the X-ray binaries (XRBs) in M33 were presented. The LFs in the soft band (0.5-2.0 keV) and the hard band (2.0-8.0 keV) have a limiting luminosity at the 90% completeness limit of 4.0 x 10<sup>34</sup> erg s<sup>-1</sup> and 1.6 x 10<sup>35</sup> erg s<sup>-1</sup> (for an assumed distance D to M33 of 817 kpc), respectively, which is significantly lower than what was reported by previous XRB population studies in galaxies more distant than M33. The resulting distribution is consistent with a dominant population of high-mass XRBs as would be expected for M33. The list of all the Chandra ACIS observations that were used in the construction of this source catalog is given in table 2 of the 2011 reference paper. X-ray source properties, such as counts, dns values, and photon fluxes were computed in the following energy bands: <pre> Band Energy Range (keV) 1 0.5 - 8.0 2 0.5 - 2.0 3 2.0 - 8.0 4 0.35- 8.0 5 0.35- 1.1 6 1.1 - 2.6 7 2.6 - 8.0 8 0.35- 2.0 </pre> This table was created by the HEASARC in April 2011 based on electronic versions of Tables 3, 4, 5, 6, 7 and 9 from the 2011 reference paper which were obtained from the ApJS web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m31cxohrc2
- Title:
- M 31 Chandra HRC X-Ray Source Catalog
- Short Name:
- M31CXOHRC2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have obtained 17 epochs of Chandra High Resolution Camera (HRC) snapshot images, each covering most of the M31 disk. The data cover a total baseline of ~2.5 yr and contain a mean effective exposure of 17 ks. The authors measured the mean fluxes and long-term light curves for 166 objects detected in these data. At least 25% of the sources show significant variability. The cumulative luminosity function (CLF) of the disk sources is well fitted by a power law with a slope comparable to those observed in typical elliptical galaxies. The CLF of the bulge is a broken power law similar to measurements made by previous surveys. The authors note several sources in the southwestern disk with L<sub>X</sub> > 10<sup>37</sup> ergs s<sup>-1</sup>. They cross-correlate all of their sources with published optical and radio catalogs, as well as new optical data, finding counterpart candidates for 55 sources. In addition, 17 sources are likely X-ray transients. Finally, the frequency of bright X-ray transients in the M31 bulge suggests that the ratio of neutron star to black hole primaries in low-mass X-ray binaries (NS/BH) is 1. The data for this project were originally part of a survey program to look for X-ray transients in M31. Nearly every month from 1999 November to 2001 February, Chandra took HRC-I images of five fields covering most of M31. Observations were then made every few months until 2002 June. The details of the 81 Chandra observations are summarized in Table 1 of the reference paper, which is available in a machine-readable form at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J_ApJ/609/735/">http://cdsarc.u-strasbg.fr/ftp/cats/J_ApJ/609/735/</a>. The authors combined all the data into three data sets using the task merge_all. One set contained the data for the northern half of the galaxy, another contained the southern half, and the last contained the center. The authors searched for sources in the three data sets using the CIAO task wavdetect. They ran this task searching for sources on four size scales: 1, 2, 4, and 8 pixels. The pixels in the merged images were 1 arcsecond in the central 18 arcmin by 18 arcmin and 2 arcsec outside of this region. By searching on several scales, wavdetect is able to overcome the large changes in the size of the Chandra PSF from about 0.5 arcsec near the center of the field to over 10 arcsec in the outer regions of the field. A total of 166 sources were detected above their 3.5-sigma detection threshold. This table was created by the HEASARC in September 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/609">CDS Catalog J/ApJ/609</a>, 735 file table2.dat . This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m108cxo
- Title:
- M 108 Chandra X-Ray Compact Source Catalog
- Short Name:
- M108CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a list of discrete sources found in a 60-ks Chandra ACIS-S observation of the isolated edge-on spiral galaxy NGC 3556 (M108). In the reference paper in which the authors present this table, they also give a multiwavelength analysis of the various discrete X-ray sources and of the diffuse X-ray features. Among 33 discrete X-ray sources detected within the I<sub>B</sub> = 25 mag arcsec<sup>-2</sup> isophotal ellipse of the galaxy, the authors identify a candidate for the galactic nucleus, an ultraluminous X-ray source that might be an accreting intermediate-mass black hole, a possible X-ray binary with a radio counterpart, and two radio-bright giant H II regions. They also detect large amounts of extraplanar diffuse X-ray emission, which extend about 10 kpc radially in the disk and >~4 kpc away from the galactic plane. The diffuse X-ray emission exhibits significant substructures, possibly representing various blown-out superbubbles or chimneys of hot gas heated in massive star-forming regions. This Chandra observation of NGC 3556 (observation ID 2025) was taken between 2001 September 8 and 9 for an exposure of 60 ks. The ACIS-S instrument was at the focal plane of the telescope. This table was created by the HEASARC in August 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/598/969">CDS Catalog J/ApJ/598/969</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m51cxo
- Title:
- M 51 Chandra X-Ray Discrete Source Catalog
- Short Name:
- M51CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of two Chandra observations (separated by 1 year) of the population of X-ray sources in the spiral galaxy M 51 (NGC 5194 and NGC 5195). One hundred and thirteen X-ray sources have been detected in an 8.4' x 8.4'(20.4 x 20.4kpc) region, and 84 and 12 of them project within the disks of NGC 5194 and NGC 5195, respectively. Nine and 28 sources have luminosities exceeding 1 x 10<sup>39</sup> erg/s (ultraluminous X-ray sources or ULXs) and 1 x 10<sup>38</sup> erg/s in the 0.5 - 8 keV band, respectively, assuming that they are associated with M 51. The number of ULXs is much higher than found in most normal spiral and elliptical galaxies. Most of the X-ray sources and all seven of the ULXs in NGC 5194 are located in, or close to, a spiral arm, suggesting a connection with recent star formation. The Chandra observations of M 51 were performed on 2000 June 20 and 2001 June 23 with the ACIS instrument. The background was stable in both observations, and effective exposure times of 14.9 and 26.8ks were obtained for the observations in 2000 and 2001, respectively. This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/601/735">CDS catalog J/ApJ/601/735</a> files table2.dat, table3.dat and table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/m81cxo
- Title:
- M 81 Chandra X-Ray Discrete Source Catalog
- Short Name:
- M81CXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- A Chandra X-Ray Observatory ACIS-S imaging observation is used to study the population of X-ray sources in the nearby (3.6 Mpc) Sab galaxy M 81 (NGC 3031). A total of 177 sources are detected, with 124 located within the D_25 isophote to a limiting X-ray luminosity of ~ 3 x 10<sup>36</sup> erg/s. Source positions, count rates, luminosities in the 0.3 - 8.0 keV band, limiting optical magnitudes, and potential counterpart identifications are tabulated. Spectral and timing analysis of the 36 brightest sources are reported, including the low-luminosity active galactic nucleus, SN 1993J, and the Einstein-discovered ultraluminous X-ray source X6. The primary X-ray data set is a 49926 s observation of M81 obtained on 2000 May 7 with the Chandra Advanced CCD Imaging Spectrometer (ACIS) spectroscopy array operating in imaging mode. The X-ray data were reprocessed by the Chandra X-ray Center (CXC) on 2001 January 4. These reprocessed data were used in this work. There are no significant differences between the reprocessed data and the originally distributed data analyzed by Tennant et al. (2001ApJ...549L..43T). The observation was taken in faint timed exposure mode at 3.241 s/frame at a focal plane temperature of -120 C. Standard CXC processing has applied aspect corrections and compensated for spacecraft dither. The primary target, SN 1993J, was located near the nominal aimpoint on the back-illuminated (BI) device S3. The nucleus of M81 lies 2.79' from SN 1993J toward the center of S3 in this observation. Accurate positions of these two objects and two G0 stars located on device S2 were used to identify any offset and to determine absolute locations of the remaining Chandra sources as well as objects in other X-ray images and those obtained at other wavelengths. No offset correction was applied to the Chandra X-ray positions. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJS/144/213, files table2.dat and table3.dat. This is a service provided by NASA HEASARC .
