- ID:
- ivo://nasa.heasarc/rasscns3
- Title:
- ROSAT All-Sky Survey: Nearby Stars
- Short Name:
- RASS/CNS3
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog presents X-ray data for all entries in the Third Catalogue of Nearby Stars (CNS3: Gliese and Jahreiss, 1991, ADC/CDS Cat. <V/70>) that have been detected as X-ray sources in the ROSAT All-Sky Survey (RASS). The catalog contains 1252 entries, yielding an average detection rate of 32.9 percent of the 3802 CNS3 stars. In addition to count rates, source detection parameters, X-ray hardness ratios, and X-ray fluxes, X-ray luminosities derived from Hipparcos parallaxes are also listed. For a star to have been considered by the authors to have been detected as an X-ray source in the RASS, an X-ray source with an existence likelihood of 7 or more (equivalent to a source existence probablity of 99.9 percent or more) had to lie within 90 arcseconds of its 1990 epoch CNS3 position. The choice of this cut-off radius was based on a Monte Carlo simulation of about the same number of random positions that were used as input positions. At an offset of 90 arcseconds between the optical and X-ray positions the probability that the X-ray source is attributable to the star and not to a unrelated background object is 50 percent; this probability increases very rapidly for smaller values of the offset, notice. This database was created in June 1999 based on tables provided by the ADC/CDS data centers supplemented by additional tabular material provided to the HEASARC by the author Dr. M. Huensch. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/rbscnvss
- Title:
- ROSAT All-Sky Survey/NVSS Bright X-Ray Source Sample
- Short Name:
- RASS/NVSS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- By cross-identifying the RASS (ROSAT All-Sky Survey) Bright Source Catalog (RBSC, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/IX/10">CDS Catalog IX/10</a>) with the NRAO VLA Sky Survey (NVSS, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/65">CDS Catalog VIII/65</a>), the authors have constructed the RBSC-NVSS sample of the brightest X-ray sources (>= 0.1 counts/s ~ 10<sup>-12</sup> erg/cm<sup>2</sup>/s in the 0.1 - 2.4keV band) that are also radio sources (S >= 2.5 mJy at 1.4 GHz) in the 7.8 sr solid angle of extragalactic sky with galactic latitude |b| > 15 degrees and declination > -40 degrees. The sky density of NVSS sources is low enough that they can be reliably identified with RBSC sources having rms positional uncertainties >= 10". The authors used the more accurate radio positions to make reliable X-ray/radio/optical identifications down to the POSS plate limits. They obtained optical spectra for many of the bright identifications lacking published redshifts. The resulting X-ray/radio sample is unique in its size (1557 objects), composition (a mixture of nearly normal galaxies, Seyfert galaxies, quasars, and clusters), and low average redshift [<z>~0.1]. This table was created by the HEASARC in September 2003 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/129/547">CDS Catalog J/ApJS/129/547</a>, files table1.dat and table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassob
- Title:
- ROSAT All-Sky Survey: OB Stars
- Short Name:
- RASS/OB
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- For detailed statistical analysis of the X-ray emission of hot stars, stars of spectral type O and B listed in the Yale Bright Star Catalogue were selected and searched for in the ROSAT All-Sky Survey. This database table displays a compilation of the derived X-ray data for a complete sample of bright OB stars. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassfirst
- Title:
- ROSAT All-Sky Survey Single FIRST Matches Catalog
- Short Name:
- RASSFIRST
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a subset of the results of a correlation of the ROSAT All-Sky Survey (RASS) with the April 1997 release of the VLA 20-cm Faint Images of the Radio Sky at Twenty cm (FIRST: <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VIII/59">CDS Cat. <VIII/59></a>) Catalog. It focusses on the analysis of the 843 X-ray sources which have unique radio counterparts. The majority of these objects (84%) have optical counterparts on the POSS 1 plates. Approximately 30% have been previously classified and the authors obtain new spectroscopic classifications for 85 sources by comparison with the ongoing FIRST Bright Quasar Survey and 106 additional sources from their own new spectroscopic data. Approximately 51% of the sources are presently classified, and the majority of the unclassified objects are optically faint. The newly classified sources are generally radio weak, exhibiting properties intermediate with previous samples of radio- and X-ray-selected AGN. This also holds for the subsample of 71 BL Lacs which includes many intermediate objects. The 146 quasars show no evidence for a bimodal distribution in their radio-loudness parameter, indicating that the supposed division between radio-quiet and radio-loud AGN may not be real. The X-ray and radio luminosities are correlated over two decades in radio luminosity, spanning the radio-loud and radio-quiet regimes, with radio-quiet quasars showing a linear correlation between the two luminosities. Many of the sources show peculiar or unusual properties which call for more detailed follow-up observations. In their paper (Table 2), the authors also give the X-ray and radio data for the 518 X-ray sources for which more than one radio object is found. Because of the difficulties inherent in identifying optical counterparts to these complex sources, they do not consider these data in the current analysis, and they are not included in the present table (but are available at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/J/A+A/356/445/">http://cdsarc.u-strasbg.fr/ftp/cats/J/A+A/356/445/</a>). This table was created by the HEASARC in March 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/356/445">CDS Catalog J/A+A/356/445</a> file table1.dat, the list of ROSAT All-Sky Survey sources with single FIRST matches. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rasshgsft2
- Title:
- ROSAT All-Sky Survey: Soft High Galactic-Latitude X-Ray Sources 2
- Short Name:
- RASSHGSFT2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a summary of spectroscopic identifications of bright soft high-galactic-latitude X-ray sources from the ROSAT All-Sky Survey (RASS) with total PSPC count rates 0.11 < CR < 0.5 cts/s and hardness ratios HR1 < 0. This study supplements the identification program of a complete sample of sources with CR >= 0.5 cts/s presented previously (Thomas et al. 1998, A&A, 335, 467; available at the HEASARC as the RASSHGSOFT table). Spectroscopic identifications are presented for 70 of 77 sources, 5 sources are identified by other means, and subsidiary information is given for 2 as yet unidentified sources. In practically all cases, a unique optical counterpart exists. As for the brighter fraction of the sample, the largest source classes are Seyfert 1 galaxies, magnetic cataclysmic variables, and hot white dwarfs. In the Galactic Pole caps at |b| > 40 degrees, Seyfert galaxies dominate, whereas at intermediate latitudes galactic objects as magnetic cataclysmic variables and white dwarfs become relatively more frequent. This table was created by the HEASARC in May 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/347/47">CDS Catalog J/A+A/347/47</a> file table3,dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rasshgsoft
- Title:
- ROSAT All-Sky Survey: Soft High Galactic-Latitude X-Ray Sources
- Short Name:
- RASS/Soft
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- A summary of spectroscopic identifications is presented for a complete sample of bright, soft, high galactic-latitude X-ray sources drawn from the ROSAT All-Sky Survey (RASS) which have PSPC count-rates CR>0.5cts/s, hardness ratios HR1<0, and galactic latitudes |b| > 20 degrees. Out of a total of 397 sources, 270 had previously catalogued counterparts, although most of these were not previously known as X-ray sources; of the remaining 127 sources neither X-ray nor optical properties were previously known. Of the whole sample of very soft X-ray sources 155 were also discovered by the Wide-Field-Camera on board ROSAT. Spectroscopic identifications are presented for 108 sources and other identifications for a further 18 sources; 1 source remains unidentified so far. In practically all cases a unique optical counterpart exists, facilitating identification. The largest source classes are AGN, magnetic cataclysmic variables, and hot white dwarfs This database was created by the HEASARC in April 1999 based on tables provided by the authors to CDS/ADC. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rass2foid
- Title:
- ROSAT All-Sky Survey Two Selected Fields Optical Identifications Catalog
- Short Name:
- RASS2FOID
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The optical identification of large number of X-ray sources such as those from the ROSAT All-Sky Survey is challenging with conventional spectroscopic follow-up observations. The authors have investigated two ROSAT All-Sky Survey fields of size 10 degrees by 10 degrees each, one at a galactic latitude b = 83<sup>o</sup> (26 Com), the other at b = -5<sup>o</sup> (gamma Sge), in order to optically identify the majority of sources. They used optical variability, among other more standard methods, as a means of identifying a large number of ROSAT All- Sky Survey sources. All objects fainter than about 12th magnitude and brighter than about 17th magnitude in or near the error circle of the ROSAT positions were tested for optical variability on hundreds of archival plates of the Sonneberg field patrol. The reference paper contains probable optical identifications of altogether 256 of the 370 ROSAT sources analyzed. In particular, the authors found 126 active galactic nuclei (some of them may be misclassified cataclysmic variables, CVs), 17 likely clusters of galaxies, 16 eruptive double stars (mostly CVs), 43 chromospherically active stars, 65 stars brighter than about 13th magnitude, 7 UV Ceti stars, 3 semi-regular or slow irregular variable stars of late spectral type, 2 DA white dwarfs, 1 Am star, 1 supernova remnant, and 1 planetary nebula. As expected, nearly all active galactic nuclei are found in the high-galactic latitude field, while the majority of CVs is located at low galactic latitudes. The authors identify in total 72 new variable objects. X-ray emission is, not unexpectedly, tightly correlated with optical variability, and thus their new method for optically identifying X-ray sources is demonstrated to be feasible. Given the large number of optical plates used, this method was most likely not more efficient than, for example, optical spectroscopy. However, it required no telescope time, only access to archival data. This table contains the optical spectroscopic and photometric properties of the 722 possible optical counterparts to the 370 ROSAT point sources found by the authors in the 2 examined fields above a maximum likelihood threshold of 8. It is essentially the union of the 314 counterparts which were listed in Table 8 (26 Com field) of the reference paper with the 408 counterparts listed in Table 9 (gamma Sge field) of that paper. We have removed 12 entries from Table 8 for which no optical counterpart was found (1033, 1050, 1060, 1085, 1091, 1103, 1129, 1166, 1177, 1190, 1217 and 1237), 1 additional entry from the same table (1071) where the X-ray emission is more likely associated with galaxy cluster gas emission rather than an individual galaxy in that cluster, and 7 entries from Table 9 (source numbers 2087-2091 and 2093-2094 which are detections of flux enhancements of an extended supernova remnant (SNR 053.6-02.2), for a total of 20 removed, since none of these entries had any positional or optical data given in the original tables. The combined lists of the X-ray sources which were given in Table 1 (26 Com field) of the reference paper and Table 2 (gamma Sge field) of that paper are available in the HEASARC table <a href="/W3Browse/rosat/rass2fxray.html">RASS2FXRAY</a> (to which the present table is linked). This table was created by the HEASARC in April 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/575/A42">CDS catalog J/A+A/575/A42</a> files table8.dat and table9.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rass2fxray
- Title:
- ROSAT All-Sky Survey Two Selected Fields X-Ray Source Catalog
- Short Name:
- RASS2FXRAY
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The optical identification of large number of X-ray sources such as those from the ROSAT All-Sky Survey is challenging with conventional spectroscopic follow-up observations. The authors have investigated two ROSAT All-Sky Survey fields of size 10 degrees by 10 degrees each, one at a galactic latitude b = 83<sup>o</sup> (26 Com), the other at b=-5<sup>o</sup> (gamma Sge), in order to optically identify the majority of sources. They used optical variability, among other more standard methods, as a means of identifying a large number of ROSAT All- Sky Survey sources. All objects fainter than about 12th magnitude and brighter than about 17th magnitude in or near the error circle of the ROSAT positions were tested for optical variability on hundreds of archival plates of the Sonneberg field patrol. The reference paper contains probable optical identifications of altogether 256 of the 370 ROSAT sources analyzed. In particular, the authors found 126 active galactic nuclei (some of them may be misclassified cataclysmic variables, CVs), 17 likely clusters of galaxies, 16 eruptive double stars (mostly CVs), 43 chromospherically active stars, 65 stars brighter than about 13th magnitude, 7 UV Ceti stars, 3 semi-regular or slow irregular variable stars of late spectral type, 2 DA white dwarfs, 1 Am star, 1 supernova remnant, and 1 planetary nebula. As expected, nearly all active galactic nuclei are found in the high-galactic latitude field, while the majority of CVs is located at low galactic latitudes. The authors identify in total 72 new variable objects. X-ray emission is, not unexpectedly, tightly correlated with optical variability, and thus their new method for optically identifying X-ray sources is demonstrated to be feasible. Given the large number of optical plates used, this method was most likely not more efficient than, for example, optical spectroscopy. However, it required no telescope time, only access to archival data. This table contains the X-ray properties of the 370 ROSAT point sources found by the authors in the 2 fields that they examined above a maximum likelihood threshold of 8. It is essentially the union of the 238 sources which were listed in Table 1 (26 Com field) of the reference paper with the 132 sources listed in Table 2 (gamma Sge field) of that paper. Notice that the source detection criterion for the ROSAT All-Sky Survey (RASS: 1RXS Catalog) had a slightly higher threshold of 10, so that the present source list is more extensive than the 1RXS Catalog source list in these two areas. The lists of the optical counterparts to these X-ray sources and their spectroscopic and photometric properties which were given in Table 8 (26 Com field) of the reference paper and Table 9 (gamma Sge field) of that paper are available in the HEASARC table RASS2FOID (to which the present table is linked). This table was created by the HEASARC in April 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/575/A42">CDS catalog J/A+A/575/A42</a> files table1.dat and table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rasswd
- Title:
- ROSAT All-Sky Survey: White Dwarfs
- Short Name:
- RASS/WDw
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table lists all white dwarf stars, both previously-cataloged and newly discovered, which have been detected in the ROSAT All-Sky Survey. The positions and count rates of the X-ray sources associated with each star are given, as well as spectral types and other star names for those stars which have been previously cataloged. This database table also lists distances estimated via Balmer line profile fitting, corrected (for IS absorption) X-ray luminosities, and each star's contribution to the X-ray luminosity function for all DA white dwarfs which were detected in the ROSAT All-Sky Survey. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rosmaster
- Title:
- ROSAT Archival Data
- Short Name:
- ROSAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains the list of all Röntgen Satellite (ROSAT) X-Ray Telescope (XRT) pointing-mode observations for which data sets are available, i.e., it excludes the ROSAT All-Sky Survey observations. Users should consult the RASSMASTER database table for those XRT observations which were made in scanning mode during the ROSAT All-Sky Survey (RASS) phase (30 July 1990 to 25 January 1991, and 3 August 1991 to 13 August 1991). For each observation listed in this table, parameters such as the focal-plane instrument used, the data processing site, and the target name and coordinates are given, as well as the ROSAT Observation Request (ROR) number, the actual and requested exposure times, the date(s) on which the observation took place, etc. For details about the ROSAT instruments, consult the ROSAT Guest Observer Facility (GOF) website at <a href="https://heasarc.gsfc.nasa.gov/docs/rosat/">https://heasarc.gsfc.nasa.gov/docs/rosat/</a>. A list of the available online ROSAT documentation can be found at <a href="https://heasarc.gsfc.nasa.gov/docs/rosat/rosdocs.html">https://heasarc.gsfc.nasa.gov/docs/rosat/rosdocs.html</a>. This table was created by the HEASARC in July 2004 by combining the data from two long-standing HEASARC Browse tables into one master table. It was updated by the HEASARC in March 2022 to add start and end times for the 157 sequence IDs which did not already have start and end times. This is a service provided by NASA HEASARC .
