- ID:
- ivo://nasa.heasarc/galcencxo
- Title:
- Galactic Center Chandra X-Ray Point Source Catalog
- Short Name:
- GALCENCXO
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of 9017 X-ray sources identified in Chandra observations of a 2 degrees by 0.8 degrees field around the Galactic center. This enlarges the number of known X-ray sources in the region by a factor of 2.5. The catalog incorporates all of the ACIS-I observations as of 2007 August, which total 2.25 Ms of exposure. At the distance to the Galactic center (8 kpc), we are sensitive to sources with luminosities of 4 x 10<sup>32</sup> erg s<sup>-1</sup> (0.5-8.0 keV; 90% confidence) over an area of 1 degree<sup>2</sup>, and up to an order of magnitude more sensitive in the deepest exposure (1.0 Ms) around Sgr A*. The positions of 60% of the sources are accurate to <1 arcsecond (95% confidence), and 20% have positions accurate to <0.5 arcsec. The authors search for variable sources, and find that 3% exhibit flux variations within an observation, and 10% exhibit variations from observation-to-observation. They also find one source, CXOUGC J174622.7-285218, with a periodic 1745 s signal (1.4% chance probability), which is probably a magnetically accreting cataclysmic variable. The authors compare the spatial distribution of X-ray sources to a model for the stellar distribution, and find 2.8 sigma evidence for excesses in the numbers of X-ray sources in the region of recent star formation encompassed by the Arches, Quintuplet, and Galactic center star clusters. These excess sources are also seen in the luminosity distribution of the X-ray sources, which is flatter near the Arches and Quintuplet than elsewhere in the field. These excess point sources, along with a similar longitudinal asymmetry in the distribution of diffuse iron emission that has been reported by other authors, probably have their origin in the young stars that are prominent at a galactic lonitude ~ 0.1 degrees. This tables was designed to be inclusive, so sources of questionable quality are included, according to the authors. For instance, 134 sources have net numbers of counts in the 0.5-8.0 keV band that are consistent with 0 at the 90% confidence level. These sources are only detected in a single band and are presumably either very hard or very soft, detected in single observations because they were transients, or detected in stacked observations with wvdecomp at marginal significance. The authors have chosen to include them because they passed the test based on Poisson statistics from Weisskopf et al. (2007, ApJ, 657, 1026). The observations which were used to generate the source list herein tabulated are listed in Table 1 of the reference paper. This HEASARC table GALCENCXO supercedes and replaces the previous HEASARC tables CHANGALCEN and CHANC150PC, which were based on Muno et al. (2003, ApJ, 589, 225) and Muno et al. (2006, ApJS, 165, 173), respectively. This table was created by the HEASARC in March 2009 based on the machine-readable versions of Table 2, 3 and 4 from the paper which were obtained from the electronic ApJ website. The information on short-term variability given in Table 5 of the reference paper was not included in this HEASARC table, notice. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/galccxonid
- Title:
- Galactic Center Chandra X-Ray Source Near-IR Counterparts
- Short Name:
- GALCCXONID
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of 5184 candidate infrared counterparts to X-ray sources detected toward the Galactic center. The X-ray sample contains 9017 point sources detected in this region by the Chandra X-ray Observatory during the past decade, including data from a recent deep survey of the central 2 degrees x 0.8 degrees of the Galactic plane. A total of 6760 of these sources have hard X-ray colors, and the majority of them lie near the Galactic center, while most of the remaining 2257 soft X-ray sources lie in the foreground. The authors have cross-correlated the X-ray source positions with the 2MASS and SIRIUS near-infrared catalogs, which collectively contain stars with a 10-sigma limiting flux of K<sub>s</sub> <= 15.6 mag. In order to distinguish absorbed infrared sources near the Galactic center from those in the foreground, they defined red and blue sources as those which have H - K<sub>s</sub> >= 0.9 and < 0.9 mag, respectively. The authors find that 5.8% =/- 1.5% (2 sigma) of the hard X-ray sources have real infrared counterparts, of which 228 +/- 99 are red and 166 +/- 27 are blue. The red counterparts are probably comprised of Wolf-Rayet and O stars, high-mass X-ray binaries, and symbiotic binaries located near the Galactic center. Foreground X-ray binaries suffering intrinsic X-ray absorption could be included in the sample of blue infrared counterparts to hard X-ray sources. The authors also find that 39.4% +/- 1.0% of the soft X-ray sources have blue infrared counterparts; most of these are probably coronally active dwarfs in the foreground. There is a noteworthy collection of ~20 red counterparts to hard X-ray sources near the Sagittarius B H II region, which are probably massive binaries that have formed within the last several Myr. For each of the infrared matches to X-ray sources in their catalog, the authors derived the probability that the association is real, based on the source properties and the results of the cross-correlation analysis. These data are included in this catalog and will serve spectroscopic surveys to identify infrared counterparts to X-ray sources near the Galactic center. This table was created by the HEASARC in October 2009 based on the electronic version of Table 3 from the reference paper which was obtained from the Astrophysical Journal web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gcps
- Title:
- Galactic Center P-Band (330 MHz) Survey
- Short Name:
- GCPS
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Galactic Center P-Band (330 MHz) Survey (GCPS) is based on wide-field, subarcminute-resolution Very Large Array (VLA) imagery of the Galactic center region at 330 MHz. With a resolution of ~7"x12" and an rms noise of 1.6 mJy/beam, this image represented a significant increase in resolution and sensitivity over the previously published VLA image at this frequency. The improved sensitivity more than tripled the census of small-diameter sources in the region, resulted in the detection of two new nonthermal filaments (NTFs), 18 NTF candidates, and 30 pulsar candidates, revealed previously known extended sources in greater detail, and has resulted in the first detection of Sagittarius A* in this frequency range. Two sets of observations were obtained. The first was conducted at 330 MHz in the A configuration of the VLA in 1996 October. The second set of P-band observations were obtained in the A and B configurations of the VLA between 1998 March and 1999 May. This Browse table was created by the HEASARC in May 2005 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/128/1646">CDS Catalog J/AJ/128/1646</a>, tables table2.dat and table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/duerbeck
- Title:
- Galactic Novae References Catalog
- Short Name:
- Nova
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains the Reference Catalog of Galactic Novae, Duerbeck, version 1990. It lists all objects known or believed to be novae at one time or other. Objects that were later found to be spurious have been omitted. Completeness was attempted only for novae and not for dwarf novae, X-ray novae, etc. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ostars
- Title:
- Galactic O Stars Catalog
- Short Name:
- OStars
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table is based upon the information contained in the Catalog of Galactic O-Type Stars (Garmany, Conti, and Chiosi 1982), which is a compilation from the literature of all O-type stars for which spectral types, luminosity classes, and UBV photometry exist. Most of the entries come from Cruz-Gonzalez, et al. (1974) and Humphreys (1978), with additional stars from Garrison and Kormendy (1976); Garrison, Hiltner, and Schild (1977); Garrison and Schild (1979); Feinstein, Marraco, and Muzzio (1973); Feinstein, Marraco, and Forte (1976); and Moffat, Fitzgerald, and Jackson (1979). As discussed below, the HEASARC has deleted 5 of the original 765 entries which we believe to be erroneous and/or redundant, and modified the names and/or positions of 14 other entries. As part of the checking process, the HEASARC created new, more accurate positions for all the entries using the SIMBAD database. The catalog contains 760 stars, for each of which designations (HD, DM, etc.), spectral types, V magnitudes, B-V magnitudes, cluster memberships, positional information, and source references are given. In addition, the authors have included derived values of absolute visual and bolometric magnitudes, and distances. The source reference should be consulted for additional details concerning the derived quantities. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/goscat
- Title:
- Galactic O Stars with Accurate Spectral Classes Catalog
- Short Name:
- GOSCAT
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have produced a catalog of 378 Galactic O stars (the GOS Catalog) with accurate spectral classifications that is complete for V < 8 but includes many fainter stars. The catalog provides cross-identifications with other sources; coordinates (obtained in most cases from Tycho-2 data); astrometric distances for 24 of the nearest stars; optical (Tycho-2, Johnson, and Stroemgren) and NIR photometry; group membership, runaway character, and multiplicity information. There is also a web-based version of this catalog with links to online services at <a href="http://www-int.stsci.edu/~jmaiz/research/GOS/GOSmain.html">http://www-int.stsci.edu/~jmaiz/research/GOS/GOSmain.html</a> This table was created by the HEASARC in February 2009 based on the electronic versions of Tables 1, 2, 5, 6, 8, 9, 10, 11, 12 and 13 obtained from the CDS, namely their catalog V/116 (files main.dat, posplx.dat, tyc2mmag.dat, ubvmag.dat and dist.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/plnebulae
- Title:
- Galactic Planetary Nebulae Catalog
- Short Name:
- Plan.Neb.
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is the 1992 Version of the Strasbourg-ESO Catalog of Galactic Planetary Nebulae (Acker et al.1992). It includes 1143 true and probable planetary nebulae (from Table 1 of the publication) and 347 objects whose status was still unclear and were thus classified among the "possible" planetary nebulae (from Table 2 of the publication); it does not include 330 objects once considered as possible planetary nebulae but which the authors have since rejected (listed in Table 3 of the publication). The designation system for the planetary nebulae listed in this catalog follows the recommendations of IAU Commission 5 (Astronomical Nomenclature) with the structure: "PN Glll.l+bb.b", where PN means "Planetary Nebula", G stands for "Galactic Coordinates", and lll.l+bb.b are the galactic longitude and latitude respectively, truncated to one decimal place. Copies of the complete catalog, including the Finding Charts (Part I) can be ordered from the ESO Information Service, Karl-Schwarzschildstr. 2, D-85748 Garching bei Muenchen, Germany. This database was created by the HEASARC in May 2001 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/V/84">CDS Catalog V/84</a>, tables main.dat, diam.dat, dist.dat, dista.dat, hbeta.dat, iras.dat, nir.dat, radio.dat, vel.dat, cstar.dat, and pospn.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/galexlog
- Title:
- Galaxy Evolution Explorer (GALEX) Observation Log
- Short Name:
- GALEXLOG
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the Galaxy Evolution Explorer (GALEX) observation log of the extant and planned observations to be made by this satellite observatory. The Galaxy Evolution Explorer (GALEX) is a NASA Small Explorer Mission launched on April 28, 2003. GALEX has been performing the first Space Ultraviolet sky survey. Five imaging surveys in each of two bands (FUV: 1350-1750 Angstroms and NUV: 1750-2800 Angstroms) range from an all-sky survey (limiting m<sub>AB</sub> ~ 20 - 21) to an ultra-deep survey of 4 square degrees (limiting m<sub>AB</sub> ~ 26). Three spectroscopic grism surveys (spectral resolution R = 100 - 300) are underway with various depths (m<sub>AB</sub> ~ 20 - 25) and sky coverage (100 to 2 square degrees) over the 1350 - 2800 Angstroms spectral range. The instrument includes a 50-cm modified Ritchey-Chretien telescope, a dichroic beam splitter and astigmatism corrector, two large, sealed-tube microchannel plate detectors to simultaneously cover the two bands and the 1.2-degree field of view. A rotating wheel provides either imaging or grism spectroscopy with transmitting optics. The GALEX mission also includes an Associate Investigator program for additional observations and supporting data analysis which supports a wide variety of investigations made possible by the first UV sky survey. The HEASARC provides this table of GALEX observations as an assistance to the high-energy astrophysics community, e.g., to enable cross-correlations of GALEX with X-ray observations. The GALEX data are available via MAST at <a href="http://galex.stsci.edu/">http://galex.stsci.edu/</a>. More information about GALEX can be found at <a href="http://www.galex.caltech.edu/">http://www.galex.caltech.edu/</a> and <a href="https://asd.gsfc.nasa.gov/archive/galex/">https://asd.gsfc.nasa.gov/archive/galex/</a>. This table was first created in July 2010 using the input file <a href="http://sherpa.caltech.edu/gips/ref/galex_obs_status.csv">http://sherpa.caltech.edu/gips/ref/galex_obs_status.csv</a> obtained from the Caltech GALEX site. This table is updated within a week of the update of the original file. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/glxsdssqso
- Title:
- GALEX/SDSS Quasar Catalog
- Short Name:
- GLXSDSSQSO
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the result of an analysis of the broad-band UV and optical properties of z ~< 3.4 quasars matched in the Galaxy Evolution Explorer (GALEX) General Data Release 1 (GR1) and the Sloan Digital Sky Survey (SDSS) Data Release 3 (DR3). Of the 6371 SDSS DR3 quasars covered by 204 GALEX GR1 tiles and listed in this table, 5380 (84%) have near-UV detections, while 3034 (48%) have both near-UV and far-UV detections using a matching radius of 7 arcseconds. Most of the DR3 sample quasars are detected in the near-UV until z ~ 1.7, with the near-UV detection fraction dropping to ~50% by z ~ 2. Statistical tests performed on the distributions of non-detections indicate that the optically selected quasars missed in the UV tend to be optically faint or at high redshift. The GALEX positions are shown to be consistent with the SDSS astrometry to within an rms scatter of 0.6 - 0.7 arcsecs in each coordinate, and the empirically determined photometric errors from multi-epoch GALEX observations significantly exceed the Poissonian errors quoted in the GR1 object catalogs. The UV-detected quasars are well separated from stars in UV-optical color-color space, with the UV-optical relative colors suggesting a marginally detected population of reddened objects due to absorption along the line of sight or dust associated with the quasar. The resulting spectral energy distributions (SEDs) cover ~350 - 9000 Angstroms (rest frame), where the overall median SED peaks near the Lyman-Alpha emission line, as found in other UV quasar studies. The large sample size allows the authors to construct median SEDs in small bins of redshift and luminosity, and they find that the median SED becomes harder (bluer) at UV wavelengths for quasars with lower continuum luminosity. The detected UV-optical flux as a function of redshift is qualitatively consistent with attenuation by intervening Lyman-absorbing clouds. This table was created by the HEASARC in October 2009 based on the electronic version of Table 2 from the reference paper which was obtained from the CDS (their catalog J/AJ/133/1780 file table2.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/glxsdssqs2
- Title:
- GALEX/SDSS z=0.5-1.5 QSO Candidates Catalog
- Short Name:
- GLXSDSSQS2
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- A sample of ~60,000 objects from the combined Sloan Digital Sky Survey-Galaxy Evolution Explorer (SDSS-GALEX) database with UV-optical colors that should isolate QSOs in the redshift range 0.5 to 1.5 is discussed. The authors use SDSS spectra of a subsample of ~ 4,500 to remove stellar and galaxy contaminants in the sample to a very high level, based on the 7-band photometry. In their paper, they discuss the distributions of redshift, luminosity, and reddening of the 19,100 QSOs (~96%) that they estimate to be present in their final sample of 19,812 point sources. This latter catalog is available in the present table. This paper is based on archival data from the Galaxy Evolution Explorer (GALEX) which is operated for NASA by the California Institute of Technology under NASA contract NAS5-98034, and on data from the SDSS. This table was created by the HEASARC in March 2011 based on the electronic version of Table 2 from the reference paper which was obtained from the AJ 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 .
