- ID:
- ivo://nasa.heasarc/fornaxacxo
- Title:
- Fornax A (NGC 1316) Chandra X-Ray Source Catalog
- Short Name:
- FORNAXACXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the results from a Chandra ACIS sub-arcsecond resolution X-ray observation of the archetypal merger radio galaxy NGC 1316 (Fornax A). The authors detect 81 point sources within the 25th magnitude isophotal ellipse D<sub>25</sub> of NGC 1316 (L<sub>X</sub> in the range of 2 x 10<sup>37</sup> to 8 x 10<sup>39</sup> ergs s<sup>-1</sup>), with hard (kT ~ 5 keV) X-ray spectra, typical of X-ray binaries, and a spatial radial distribution consistent with that of the optical (i.e., stellar) surface brightness. In the reference paper, they derive the X-ray luminosity function (XLF) of these sources, correcting for the incompleteness at the faint end caused by the presence of the diffuse emission from the hot ISM in the central regions of NGC 1316 and by the widening of the Chandra point-spread functions at increasing distance from the aim point. With these corrections, the XLF is well reproduced by a single unbroken power law with a slope of -1.3 down to their threshold luminosity of ~ 3 x 10<sup>37</sup> ergs s<sup>-1</sup>. NGC 1316 was observed for 30 ks on 2001 April 17 (ObsID 2022), with the Chandra Advanced CCD Imaging Spectrometer (ACIS). The authors used the back-illuminated (BI) CCD S3 (CCD ID 7) because of its sensitivity at low energies. To include NGC 1317 (6.3 arcminutes away from NGC 1316) in the same S3 chip, a small offset was applied to the SIM (Science Instrument Module) position. NGC 1316 was kept close to on-axis to achieve the best spatial resolution. To detect X-ray sources, the authors used WAVDETECT, a wavelet detection algorithm available in CIAO. They set the WAVDETECT significance threshold parameter to be 10<sup>-6</sup>, which corresponds to 1 possibly spurious source, and the scale parameter to cover seven steps between 1 and 64 pixels. This made them sensitive to sources ranging from point-like to 32 arcseconds in size, and in particular accommodates the variation of the point-spread function (PSF) as a function of the off-axis angle of the sources. To extract source properties (such as count rates, spectra, etc.), the authors used the 95% encircled energy (at 1.5 keV) radius centered at the WAVDETECT centroid, with a minimum of 3 arcseconds to accommodate the radial variation of he PSF. Background counts were determined locally for each source from an annulus from 2 to 5 times the source radius, after excluding nearby sources. Extended sources were found at the locations of NGC 1316 and NGC 1317. In addition, the Chandra observations reveal 94 sources (the HEASARC notes that 95 are contained in this table), 83 of them in CCD S3. Of these, 81 sources (77 in S3 and 4 in S2) are within the D<sub>25</sub> ellipse. The source density increases toward the center of NGC 1316, indicating that most of them are related to NGC 1316. Three sources are found within the D<sub>25</sub> ellipse of NGC 1317, with the brightest, extended one at the center of NGC 1317. The list of detected sources also includes sources found on CCDs other than S3 (CCD number 7). After correcting for effective exposure and vignetting, the X-ray flux in the 0.3 - 8.0 keV band is calculated with an energy conversion factor (ECF) assuming a power-law source spectrum with a slope of 1.7 and N<sub>H</sub> = 3 x 10<sup>20</sup> cm<sup>-2</sup>; ECF = 6.037 x 10<sup>-12</sup> erg cm<sup>-2</sup> s<sup>-1</sup> ergs per 1 count s<sup>-1</sup> for the back-illuminated (BI) chips and 9.767 x 10<sup>-12</sup> ergs per 1 count s<sup>-1</sup> for the front-illuminated (FI) CCD chips. With the adopted distance of 18.6 Mpc, the X-ray luminosities of the point sources range from ~ 2 x 10<sup>37</sup> to ~ 8 x 10<sup>39</sup> erg s<sup>-1</sup>. This table was created by the HEASARC in July 2014 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/586/826">CDS Catalog J/ApJ/586/826</a> file table1.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/fornaxxmm
- Title:
- Fornax Dwarf Galaxy XMM-Newton X-Ray Point Source Catalog
- Short Name:
- FORNAXXMM
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the results of a deep archive XMM-Newton observation of the Fornax spheroidal galaxy that the authors analyzed with the aim of fully characterizing the X-ray source population (in most of the cases likely to be background active galactic nuclei) detected towards the target. A cross-correlation with the available databases allowed them to find a source that may be associated with a variable star belonging to the galaxy. The authors also searched for X-ray sources in the vicinity of the Fornax globular clusters GC 3 and GC 4 and found two sources probably associated with the respective clusters. The deep X-ray observation was also suitable for the search for the intermediate-mass black hole (of mass ~ 10<sup>4</sup> solar masses) expected to be hosted in the center of the galaxy. In the case of Fornax, this search is extremely difficult since the galaxy centroid of gravity is poorly constrained because of the large asymmetry observed in the optical surface brightness. Since the authors cannot firmly establish the existence of an X-ray counterpart of the putative black hole, they put constraints only on the accretion parameters. In particular, they found that the corresponding upper limit on the accretion efficiency, with respect to the Eddington luminosity, is as low as a few 10<sup>-5</sup>. This table was created by the HEASARC in February 2013 based on an electronic version of Table 1 from the reference paper which was obtained from the A&A web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/gleamegcat
- Title:
- GaLactic and Extragalactic All-sky MWA Survey (GLEAM) Extragalactic Catalog
- Short Name:
- GLEAMEGCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Using the Murchison Widefield Array (MWA), the low-frequency Square Kilometre Array (SKA1 LOW) precursor located in Western Australia, the authors have completed the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, and present the resulting extragalactic catalog, utilizing the first year of observations. The catalog covers 24,402 square degrees, over Declinations south of +30 degrees and Galactic latitudes outside 10 degrees of the Galactic Plane, excluding some areas such as the Magellanic Clouds. It contains 307,455 radio sources with 20 separate flux density measurements across 72 - 231 MHz, selected from a time- and frequency-integrated image centered at 200 MHz, with a resolution of ~ 2 arcminutes. Over the catalogued region, the authors estimate that the catalog is 90% complete at 170 mJy, and 50% complete at 55 mJy, and large areas are complete at even lower flux density levels. Its reliability is 99.97% above the 5-sigma detection threshold, which itself is typically 50 mJy. These observations constitute the widest fractional bandwidth and largest sky area survey at radio frequencies to date, and calibrate the low frequency flux density scale of the southern sky to better than 10%. The reference paper presents details of the flagging, imaging, mosaicking, and source extraction/characterization, as well as estimates of the completeness and reliability. All source measurements and images are available online at <a href="http://www.mwatelescope.org/">http://www.mwatelescope.org/</a>. This is the first in a series of publications describing the GLEAM survey results. GLEAM observes in week-long drift scan campaigns, with a single Dec strip observed each night. The observing bandwidth of 72-231 MHz is covered by shifting frequencies by 30.72 MHz every two minutes, avoiding the Orbcomm satellite constellation at 134-139 MHz. Thus, the frequencies of observation are 72-103, 103-134, 139-170, 170-200. and 200-231 MHz. These may be further subdivided for imaging purposes; in this study, the 30.72 MHz bandwidth is commonly subdivided into four 7.68 MHz sub-channels. The native channel resolution of these observations is 40 kHz and the native time resolution is 0.5 seconds. This paper concerns only data collected in the first year, i.e. four weeks between June 2013 and July 2014. The authors also do not image every observation, since the survey is redundant across approximately 50% of the observed RA ranges, and some parts are adversely acted by the Galactic plane and Centaurus A. Table 1 in the reference paper lists the observations which have been used to create this first GLEAM catalog. The HEASARC has converted the flux density units from those given in the original table (Jy and Jy/beam) to its standard units for radio flux densities (mJy and mJy/beam). This table was originally ingest by the HEASARC in February 2017 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/100">CDS Catalog VIII/100</a> file gleamegc.dat, the GLEAM Extragalactic Catalog. It was updated in May 2018 to the corrected version provided to the CDS by the author. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/galcencxo
- Title:
- Galactic Center Chandra X-Ray Point Source Catalog
- Short Name:
- GALCENCXO
- Date:
- 07 Mar 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 .
- ID:
- ivo://nasa.heasarc/galccxonid
- Title:
- Galactic Center Chandra X-Ray Source Near-IR Counterparts
- Short Name:
- GALCCXONID
- Date:
- 07 Mar 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:
- 07 Mar 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:
- 07 Mar 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:
- 07 Mar 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:
- 07 Mar 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:
- 07 Mar 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 .
