- ID:
- ivo://nasa.heasarc/tartarus
- Title:
- Tartarus: Reduced ASCA AGN Data (Version 3.1)
- Short Name:
- ASCA/AGN
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Tartarus database contains the results of a detailed but systematic analysis of ASCA observations of active galactic nuclei (AGN). It contains source and background events files, spectra, ancillary response files and response matrices, images, and assorted light curves for a large number of ASCA AGN observations. Spectral fit results are done by automatic XSPEC fitting. This database table allows easy access to reduced AGN data for the whole community, allowing the maximum scientific return from the data. Availability of publishable light curves, images, and spectra (which can also be readily re-fitted) should be particularly valuable to astronomers with little direct experience in the reduction of X-ray data. Version 3.1 has been created by analyzing all ASCA observing sequences with targets designated as AGN, as indicated by a leading "7" in the ASCA observing sequence number. Version 3.1 contains products for all 611 observing sequences designated as AGN observations. This is a significant improvement over Versions 1 and 2. Moreover, the 611 sequences for which products are available are complete in the sense that either the target object was not detected (in which case an upper limit on GIS2 source counts is given) or the intended AGN target was detected and the data were fully analyzed. In order to obtain the most accurate background subtraction and minimize contamination from any nearby sources, version 3.1 makes more use of custom extraction regions than previous versions. It is expected that version 3.1 will be replaced when the final ASCA calibration is completed. This database table has been created by the Tartarus Team, and they, rather than Imperial College London or the HEASARC, are responsible for the contents. It was ingested by the HEASARC in August, 2005. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/taurusxmm
- Title:
- Taurus Molecular Cloud XMM-Newton X-Ray Source Catalog
- Short Name:
- TAURUSXMM
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) surveys the most populated ~5 square degrees of the Taurus Molecular Cloud, using the XMM-Newton X-ray observatory to study the thermal structure, variability, and long-term evolution of hot plasma, to investigate the magnetic dynamo, and to search for new potential members of the association. The authors present overall correlations with fundamental stellar parameters that were derived from the previous literature. The present overview paper introduces the project and provides the basic results from the X-ray analysis of all sources detected in the XEST survey. Comprehensive tables in the published paper summarize the stellar properties of all the targets surveyed. The survey goes deeper than previous X-ray surveys of Taurus by about an order of magnitude and for the first time systematically accesses very faint and strongly absorbed TMC objects. The authors find a detection rate of 85% and 98% for classical and weak-line T Tauri stars (CTTS and WTTS), respectively, and identify about half of the surveyed protostars and brown dwarfs. Overall, 136 out of 169 surveyed stellar systems were detected. The authors describe an X-ray luminosity vs. mass correlation, discuss the distribution of X-ray-to-bolometric luminosity ratios, and show evidence for lower X-ray luminosities in CTTS compared to WTTS. The complete catalog of all X-ray sources (stellar and non-stellar) detected in the 28 XEST fields is presented in this table. The catalog provides X-ray coordinates, their uncertainties, X-ray count rates and their uncertainties, and X-ray hardness ratios for 2347 detected X-ray sources. If two XEST fields overlap, the same sources may have been identified twice, with different XEST IDs assigned, notice. This table was created by the HEASARC in July 2007 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/468/353">CDS Catalog J/A+A/468/353</a> file table14.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/td1
- Title:
- TD1 Stellar Ultraviolet Fluxes Catalog
- Short Name:
- TD1
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Belgian/UK Ultraviolet Sky Survey Telescope (S2/68) in the ESRO TD1 satellite carried out a controlled scan of the entire sky. It measured the absolute ultraviolet flux distribution between 2740A and 1350A of point sources down to 10th visual magnitude for unreddened early B stars. The S2/68 experiment has been described by Boksenberg et al. (1973MNRAS.163..291B), and the absolute calibration by Humphries et al. (1976A&A....49..389H). The TD1 Catalog of Stellar Ultraviolet Fluxes represents results from the sky-scan experiment on the TD1 satellite of the European Space Research Organization (ESRO), now part of ESA. It lists the absolute fluxes, in four passbands, for 31,215 stars: <pre> Passband Center: 274.0nm 236.5nm 196.5nm 156.5nm Effective Width: 31.0nm 33.0nm 33.0nm 33.0nm </pre> The stars have been selected subject to the constraint that the signal-to-noise ratio should be at least 10.0 in any one of the four passbands. Null values of a flux field and an error field indicate there are no valid data for the star. This usually arises with close pairs of stars whose spectra overlap. Five standard flux error values are greater than 99.99, and were too large for the format of the flux field in the original table. Thus, the flux error values which were greater than 99.99 are given as 99.99. Many of the fainter stars of spectral type later than A5 do not have significant signals in all of the spectrophotometric channels (particularly the 1565A channel). Consequently, after the removal of the background, they can randomly give rise to small negative values of flux. Those negative values were not suppressed, but are given together with their error, as they can be significant when considered as part of a statistical sample. Although the sky coverage is essentially complete, the catalog does not contain the fluxes for all stars that fall within the limit of the sensitivity of the instrument. If any star expected to be present is missing, then its signal is probably blended with that of a nearby star, in which case the data have been discarded. The original contents of the HEASARC's TD1 database table came from a magnetic tape sent to NASA/Goddard Space Flight Center by Dr. G.I. Thompson of the Royal Observatory in Edinburgh, Scotland. The HEASARC recreated this database table in August 2005, based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/59B">CDS Catalog II/59B</a> file catalog.dat.gz, in an effort to modernize its parameter names and documentation, as well as to add Galactic coordinates. The data in the CDS version originally came from "Selected Astronomical Catalogs" Vol. 1 CD-ROM released by the NASA Astronomical Data Center (ADC) in 1991. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/tevcat
- Title:
- TeV Gamma-Ray Source Catalog
- Short Name:
- TEVCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- TeVCat (<a href="http://tevcat.org/">http://tevcat.org/</a>) is an online, interactive catalog for very-high-energy (VHE: energies, E >~ 50 GeV) gamma-ray astronomy. As VHE astronomy continues to grow, the usefulness of a one-stop clearing house for information on new sources is increasingly evident. TeVCat is intended to be such a resource. With sky maps, scientific information, visibility plotters and linked references available at the website, it will help the wider gamma-ray community stay up-to-date and informed on this exciting and rapidly developing field. This HEASARC database table provides the TeVCat list of VHE sources as well as links to the TeV source resource pages on the TeVCat website. The catalog and <a href="http://tevcat.org/">the website at the University of Chicago</a> are maintained by Scott Wakely and Deirdre Horan. This table was first ingested by the HEASARC in July 2017 based on the catalog of VHE gamma-ray sources available at <a href="http://tevcat.org/">http://tevcat.org/</a>. It is updated automatically within a few days of the catalog being updated on the University of Chicago website. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/texas
- Title:
- Texas Survey of Radio Sources at 365 MHz
- Short Name:
- Texas
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog is from the Texas Survey of discrete radio sources between -35.5 degrees and +71.5 degrees declination (B1950), which was carried out at a frequency of 365 MHz (82 cm wavelength) with the Texas Interferometer during the period from 1974 to 1983. The Survey lists accurate positions with internal errors of about an arcsecond, flux densities (which for strong point sources have internal errors of about 1% and total errors of about 5%), simple structure models and indications of spectrum and variability for 66841 sources. Results of comparisons with other data show that the Survey is 90% complete at 0.4 Jy and 80% complete at 0.25 Jy, is nearly free from spurious sources, and has a lobeshift incidence which is reasonably described by quality flags associated with each source. The University of Texas Radio Astronomy Observatory (UTRAO) carried out, with the Texas Interferometer, this 365 MHz survey of the sky, which was intended to be complete to a flux density level of 0.25 Jy, to provide positions with an accuracy of about 1 arcsec in both coordinates, to give accurate flux densities and indication of source variability, and to give rough structure models for each source. The observations began in 1974 and were completed in 1983. A preliminary version of one declination strip was published (Douglas et al., Publ. Dept. Astron. Univ. Texas, No. 17, Oct. 1980), and a number of intermediate versions of the survey were privately circulated for various purposes, pending completion of the final analysis and adjustment of the data. This database was created by the HEASARC in February 2001, based on CDS/ADC catalog VIII/42. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/swif1swxrt
- Title:
- The Seven-Year Swift-XRT Point Source Catalog (1SWXRT)
- Short Name:
- SWIF1SWXRT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the 1SWXRT catalog of point sources detected by X-ray Telescope (XRT) on board of the Swift satellite during the first seven years of operation (Jan 2005 - Dec 2011). Swift is a NASA mission with international participation dedicated to gamma-ray burst study. It carries three instruments. The BAT is the large field of view instrument and operates in the 10-300 keV energy band; and two narrow field instruments, XRT and UVOT, that operate in the X-ray and UV/optical regime, respectively. The seven-year Swift-XRT point source catalog (1SWXRT) was built using all the observations performed by Swift-XRT in PC observing mode with an exposure longer than 500 s. The total number of observations considered is 35011, for an overall exposure time of ~140 Ms. Different observations with same pointing were not merged, but analyzed separately, thus retaining information about the variability of the catalogued sources. Most of the observations have short exposures. In fact, ~18% have t<sub>exp</sub> < 1 ks and ~77% have t<sub>exp</sub> < 5 ks. Only 7% of the observations have an exposure time > 10 ks, which are mostly (but not exclusively) fields associated with GRBs. The catalog was generated by running the detection algorithm in the XIMAGE package version 4.4.1 that locates the point sources using a sliding-cell method. The average background intensity is estimated in several small square boxes uniformly located within the image. The position and intensity of each detected source are calculated in a box whose size maximizes the signal-to-noise ratio. For each detection the catalog reports three count rates in the 0.3-3 (Soft), and 2-10 (Hard), and 0.3-10 (Full) keV energy bands. Each are corrected for dead times and vignetting using exposure maps and for the PSF. Hardness ratios are calculated using the three energy band and defined as HR = (c<sub>H</sub> - c<sub>S</sub>)/(c<sub>H</sub> + c<sub>S</sub>) where c<sub>S</sub> and c<sub>H</sub> are the count rates in the S(oft) and H(ard) bands, respectively. The catalog was cleaned from spurious and extended sources by visual inspection of all the observations. Count rates in the three bands were converted to 0.5-10, 0.5-2, and 2-10 keV observed fluxes, respectively. For the fluxes these energy bands were adopted to easy comparison with other X-ray catalogs (Watson, M. G. et al. 2009, A&A, 493, 339; Evans, I. N. et al. 2010, ApJ, 189, 37). The count rate to flux conversion was made using an absorbed power-law. The absorption is the Galactic hydrogen column density in the direction of the source and the photon spectral index has been estimated through the hardness ratio. Each row in the catalog is a detection not a unique source since the analysis was done by observation. Since multiple observations have covered the same part of the sky, a source may be detected more than once. The total number of detections is 84979 with an estimated 36000 unique sources as reported in the D'Elia et al. paper. The number of unique sources is derived by considering as one source all detections that have their positions within 12 arcsec. However, the catalog does not have a marker to identify all detections of a unique source. This database table was created by the HEASARC in November 2021 based on the electronic version available from the ASI Data Center <a href="https://www.asdc.asi.it/1swxrt/">https://www.asdc.asi.it/1swxrt/</a> and published in the Astronomy and Astrophysics Journal. This catalog is also available as <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/551/A142">CDS catalog J/A+A/551/A142</a>. The HEASARC added the id_number parameter, a counter to numerically identify each detection in the catalog (since the names of the detections are not unique), . Note that there is a discrepancy in the number of detections in the electronic version which has 84979 records and the number of detections reported in the paper (84992). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/wrcat
- Title:
- The VIIth Catalog of Galactic Wolf-Rayet Stars
- Short Name:
- WR
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The VIIth Catalogue of Galactic Population I Wolf-Rayet (WR) Stars provides improved coordinates, spectral types, and bv photometry of known WR stars and adds 71 new stars compared to the VIth Catalog. This census of galactic WR stars has reached 227 stars (226 entries in this catalog), comprising 127 WN stars, 87 WC stars, 10 WN/WC stars, and 3 WO stars. This includes 15 WNL and 11 WCL stars within 30 pc of the Galactic Center. The catalog includes information on periodicity, binarity, terminal wind velocities, correlations with open clusters, OB associations, H I bubbles, H II regions, and ring nebulae, observed and dereddened narrow-band bv photometry, and distances, both heliocentric and galactocentric, and lists the references from which this information was obtained. This catalog was created by the HEASARC in April 2001, based on electronic versions of Tables 13, 14, 15, and 28 from the published paper containing the catalog which were directly supplied to the HEASARC by the author. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermi3fhl
- Title:
- Third Catalog of Hard Fermi-LAT Sources (3FHL)
- Short Name:
- FERMI3FHL
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is a catalog of sources detected above 10 GeV by the Fermi-Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. It contains 1558 objects characterized in the 10 GeV to 2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog at the same energies (1FHL). The vast majority of detected sources (79%) are extragalactic, including 16 sources located at very high redshift (z > 2). Nine percent of the sources are Galactic and 12% are unassociated (or associated with a source of unknown nature). The high-latitude sky and the Galactic plane are observed with an average sensitivity of 0.5% and 1% of the Crab Nebula flux above 10 GeV, respectively. The catalog includes 225 new gamma-ray sources. The substantial increase in the number of photons (more than 4 times relative to the 1FHL and 10 times to the 2FHL) also allows us to characterize spectral curvature for 32 sources and flux variability for 163 of them. Furthermore, we estimate that for the same energy flux limit of 10<sup>-12</sup> erg cm<sup>2</sup> s<sup>-1</sup>, the energy range above 10 GeV has twice as many sources as the range above 50 GeV, which confirms and quantifies the importance of lowering the energy threshold of Cherenkov telescopes as much as possible in order to increase the number of available sources. This database table was first ingested by the HEASARC in December 2017 using electronic data obtained from the Fermi Science Support Center (FSSC). That data is available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/3FHL/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/3FHL/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rc3
- Title:
- Third Reference Catalog of Bright Galaxies
- Short Name:
- RC3
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the machine-readable version of the Third Reference Catalogue of Bright Galaxies (RC3) by G. de Vaucouleurs, A. de Vacouleurs, H.G. Corwin, R.J. Buta, P. Fouque, and G. Paturel, originally published by Springer-Verlag in 1991, and including some corrections and additions made by Corwin et al. (1994, AJ, 108, 2128). Only brief parameter descriptions are given in this help file. Detailed information about, for example, how certain quantities were derived, or exactly what a given code means, can be found in the printed version of RC3. This table was created by the HEASARC in March 2007 based on CDS table VII/155/rc3, and replaced an earlier version which did not contain the corrections made by Corwin et al. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/trifidcxo
- Title:
- Trifid Nebula (M 20) Chandra X-Ray Point Source Catalog
- Short Name:
- TRIFIDCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a list of the Trifid Nebula (M 20) X-Ray point sources detected by the Chandra X-ray Observatory (CXO) in an observation carried out on 2002 June 13. The Trifid Nebula, a young star-forming H II region, was observed for 16 hr by the Advanced CCD Imaging Spectrometer imaging array, ACIS-I, detector. 304 X-ray sources were detected, 30% of which are hard sources (defined as those sources having a 0.5-2.0 keV to 2.0-8.0 keV hardness ratio > -0.2) and 70% of which have near-infrared counterparts. This table was created by the HEASARC in January 2007 based on CDS table J/ApJ/607/904/table1.dat. This is a service provided by NASA HEASARC .
