- ID:
- ivo://nasa.heasarc/euvexrtcat
- Title:
- All-Sky Catalog of Faint EUV Sources
- Short Name:
- EUV/Faint
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The All-Sky Catalog of Faint Extreme-Ultraviolet (EUV) Sources is a list of 534 objects detected jointly in the Extreme Ultraviolet Explorer (EUVE) (100 Angstrom (AA) band) All-Sky Survey and in the ROSAT X-ray Telescope (XRT) (0.25 keV band) All-Sky Survey. The joint selection criterion within a 1.5 arcminute positional tolerance permitted the use of a low count rate threshold in each survey. This low threshold was roughly 60% of the threshold used in the previous EUVE all-sky surveys, and 166 of the objects listed in this table were new EUV sources, appearing neither in the Second EUVE Source Catalog nor in the ROSAT Wide Field Camera Second Catalog. Preliminary identifications are offered for 105 of the 166 sources not previously reported in any EUV catalog: by far the most numerous (81) of the identifications are late-type (F-M) stars, while 18 are other stellar types, only 5 are white dwarfs, and none are extragalactic. The paucity of WDs and extragalactic objects may be explained by a strong horizon effect wherein interstellar absorption strongly limits the effective new-source search volume, and, thereby, selectively favors low-luminosity nearby sources over more luminous but distant objects. Notice that, with the adopted 1.5 arcminute acceptance criterion, about 50 spurious detections are expected. This Browse table was created in July 2003 based on CDS table IX/35/faint.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/bmwhricat
- Title:
- Brera Multi-scale Wavelet ROSAT HRI Source Catalog
- Short Name:
- BMW-HRI
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Brera Multi-scale Wavelet ROSAT High Resolution Imager Source Catalog (BMW-HRI) is derived from all ROSAT HRI pointed observations with exposure time longer than 100 seconds available in the ROSAT public archives. The data were analyzed automatically using a wavelet detection algorithm suited to the detection and characterization of both point-like and extended sources. This algorithm is able to detect and disentangle sources in very crowded fields and/or in presence of extended or bright sources. Images have been also visually inspected after the analysis to ensure verification. The final catalog, derived from 4,303 observations, consists of 29,089 sources detected with a detection probability of greater or equal 4.2 sigma. For each source, the primary catalog entries provide name, position, count rate, flux and extension along with the relative errors. In addition, results of cross-correlations with existing catalogs at different wavelengths (FIRST, IRAS, 2MASS, and GSC2) are also reported. As an external check, the authors compared their catalog with the previously available ROSHRICAT catalog (both in its short and long versions) and were able to recover, for the short version, ~90% of the entries. The sky coverage of the entire HRI data set was computed by means of simulations. The complete BMW-HRI catalog provides a sky coverage of 732 square degrees down to a limiting flux of ~1x10<sup>-12</sup> erg/s/cm<sup>2</sup> and of 10 square degrees down to ~1x10<sup>-14</sup> erg/s/cm<sup>2</sup>. The authors were able to compute the cosmological log(N)-log(S) distribution down to a flux of about 1.2x10<sup>-14</sup> erg/s/cm<sup>2</sup>. This catalog was ingested by the HEASARC in March 2003, based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/IX/34">CDS Catalog IX/34</a> file catalog.dat.gz. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/bhrfscid
- Title:
- Byurakan/Hamburg/ROSAT Catalog of Optical IDs
- Short Name:
- BHROSATOpt.
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the Byurakan/Hamburg/ROSAT Catalog (BHRC) of the optical identifications of X-ray sources. The BHRC includes all 2791 X-ray sources from the ROSAT Faint Source Catalog (ROSAT-FSC, CDS Catalog <IX/29>) with galactic latitude |b| >= 30 degrees, declination >= 0 degrees, and ROSAT PSPC count rate CR > 0.04 ct/s. The optical identifications were carried out using the Hamburg Quasar Survey (HQS) digitized spectroscopic plates, the DSS1 and DSS2 (blue, red, and IR) images, the MAPS photometric data, the USNO-B1.0 (for proper motion), the NVSS and FIRST radio, and the IRAS and 2MASS infrared catalogs. From the DSS images, positional, brightness, color, extension, variability, and proper-motion information, the optical-to-X-ray positional offsets were obtained and a morphological classification was made. Available SIMBAD and NED data were also utilized. Cross-correlations were made with AGN, white dwarf, and cataclysmic variable catalogs (322, 8 and 7 associations, respectively). The authors managed to identify 97% of the sources (2696/2791 sources) that are associated with 3202 optical objects. 2248 X-ray sources have a single optical counterpart, 144 have a double or multiple optical counterpart (binaries, galaxy groups, etc.), and 304 have ambiguous identifications (some of the latter might actually be blends of two X-ray sources that were not resolved by ROSAT). The QSOs and AGN represent the largest group of X-ray counterparts (56.2%); bright stars (including late-type stars, but excluding WDs and CVs) are counterparts for 33.2% of the sources, and bright galaxies and groups of galaxies comprise 9.2%. A number of close galaxy pairs (possibly interacting/merging galaxies) are found as counterparts for X-ray sources (3.0%), as well as 1.0% WDs and 0.4% CVs. The BHRC may be used for the selection and study of samples of the various classes of X-ray emitters: the table gives all the available multiwavelength data for the identified sources. This table was created by the HEASARC in June 2006 based on CDS table J/A+A/449/425/table1.dat This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/etgalxray
- Title:
- Early-Type Galaxies X-Ray Luminosities Catalog
- Short Name:
- ETGALXRAY
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of X-ray luminosities for 401 early-type galaxies (and 24 other galaxies which were listed in previuous studies as early but which have LEDA T-types >= -1.5), of which 136 are based on newly analysed ROSAT PSPC pointed observations. The remaining luminosities are taken from the literature and converted to a common energy band, spectral model and distance scale. In their paper, the authors use this sample to fit the L<sub>X</sub>/L<sub>B</sub> relation for early-type galaxies and find a best-fit slope for the catalog of ~ 2.2. The authors demonstrate the influence of group-dominant galaxies on the fit and present evidence that the relation is not well modeled by a single power-law fit. They also derive estimates of the contribution to galaxy X-ray luminosities from discrete-sources and conclude that they provide L<sub>(discrete-source-contribution)</sub>/L<sub>B</sub> ~ 29.5 erg s<sup>-1</sup>/L<sub>Bsun</sub>. The authors compare this result with luminosities from their catalog. Lastly, they examine the influence of environment on galaxy X-ray luminosity and on the form of the L<sub>X</sub>/L<sub>B</sub> relation. They conclude that although environment undoubtedly affects the X-ray properties of individual galaxies, particularly those in the centres of groups and clusters, it does not change the nature of whole populations. The sample of early-type galaxies was selected from the Lyon-Meudon Extragalactic Data Archive (LEDA). This catalog at that time contained information on ~ 100,000 galaxies, of which ~ 40,000 had redshift and morphological data. Galaxies were selected using the following criteria: (i) Morphological Type T < -1.5 (i.e. E, E-S0 and S0 galaxies). (ii) Virgo-corrected recession velocity V <= 9,000 km s<sup>-1</sup>. (iii) Apparent Magnitude B<sub>T</sub> <= 13.5. The redshift and apparent magnitude restrictions were chosen in order to minimize the effects of incompleteness on their sample. The LEDA catalogue is known to be 90 per cent complete at B<sub>T</sub> = 14.5, so the selection should be close to statistical completeness. The selection process produced ~ 700 objects. The authors then cross-correlated this list with a list of public ROSAT PSPC pointings. Only pointings within 30 arcminutes of the target were accepted, as, further off-axis, the PSPC point-spread function becomes large enough to make analysis problematic. This left 209 galaxies with X-ray data available. The authors also added data from previously published catalogs, ROSAT PSPC All-Sky Survey values from Beuing et al. (1999, MNRAS, 302, 209), and Einstein IPC values from Fabbiano et al. (1992, ApJS, 80, 531) and Roberts et al. (1991, ApJS, 75, 751). These other references use a range of models to fit the data, different wavebands, distances and blue luminosities. O'Sullivan et al. corrected for these differences by converting the catalogs to a common set of values, as used for their own results. All of the X-ray luminosities have been converted to a common format based on a reliable distance scale (assuming H<sub>0</sub> = 75 km s<sup>-1</sup> Mpc<sup>-1</sup>), and correcting for differences in spectral fitting techniques and waveband. This table was created by the HEASARC in October 2010 based on CDS catalog J/MNRAS/328/461 file table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/hrasscat
- Title:
- Hamburg/RASS Catalog: X-Ray Sources
- Short Name:
- RASS/HRC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table is a representation of part of the Hamburg/ROSAT All-Sky Survey (RASS) Catalog (HRC) of optical identifications of X-ray sources at high-galactic latitude, namely the list of X-ray sources. (The list of proposed and possible optical counterparts is given in the linked Browse table HRASSOPTID). The HRC includes all X-ray sources from the ROSAT Bright Source Catalog (RASS-BSC) with galactic latitude |b| >= 30 degrees and declination Dec >= 0 degrees. In this part of the sky covering ~10,000 square degrees, the RASS-BSC contains 5341 X-ray sources. For the optical identification, the HRC authors used blue Schmidt prism and direct plates taken for the northern hemisphere Hamburg Quasar Survey (HQS) which are now available in digitized form. The limiting magnitudes are 18.5 and 20, respectively. For 82% of the selected RASS-BSC, an identification could be given. For the rest, either no counterpart was visible in the error circle, or a plausible identification was not possible. With ~42%, AGN represent the largest group of X-ray emitters, ~31% have a stellar counterpart, whereas galaxies and cluster of galaxies comprise only ~4% and ~5%, respectively. In ~3% of the RASS-BSC sources, no object was visible on the blue direct plates within 40" around the X-ray source position. The catalog has been used as a source for the selection of (nearly) complete samples of the various classes of X-ray emitters. This table was produced by the HEASARC in February 2005 based on the CDS Catalog table J/A+A/406/353/x-ray.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassasaseb
- Title:
- RASS/All-Sky Automated Survey Eclipsing Binaries Catalog
- Short Name:
- RASSASASEB
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have combined their catalog of eclipsing binaries from the All-Sky Automated Survey (ASAS) with the ROSAT All-Sky Survey (RASS) Bright and Faint Source Catalogs (RASSBSC and RASSFSC). The combination using a matching radius of 50 arcseconds results in 836 eclipsing binaries that display coronal activity and is the largest sample of active binary stars assembled to the date of publication. By using the (V-I) colors of the ASAS eclipsing binary catalog, the authors are able to determine the distances and thus bolometric luminosities for the majority of eclipsing binaries that display significant stellar activity. A typical value for the ratio of soft X-ray to bolometric luminosity is L<sub>X</sub>/L<sub>bol</sub> ~ a few x 10<sup>-4</sup>, similar to the ratio of soft X-ray to bolometric flux F<sub>X</sub>/F<sub>bol</sub> in the most active regions of the Sun. Unlike rapidly rotating isolated late-type dwarfs - stars with significant outer convection zones - a tight correlation between Rossby number and activity of eclipsing binaries is absent. The authors find evidence for the saturation effect and marginal evidence for the so-called "super-saturation" phenomena. Their work shows that wide-field stellar variability searches can produce a high yield of binary stars with strong coronal activity. The authors expect that only 1.4% (i.e., 12 out of 836) of the matches between the ASAS eclipsing binary and RASS sources will be false given their maximum angular separation criterion of 50 arcseconds. This Browse table excludes 29 contact binaries for which the separate distance estimates made by the authors using the source V-band and I-band magnitudes differed by more than 20%, and hence contains 807 (836 - 29) eclipsing and X-ray emitting binary systems. Complete information on ASAS and its freely accessible data are available at the ASAS web site: <a href="http://www.astrouw.edu.pl/asas/">http://www.astrouw.edu.pl/asas/</a>. This table was created by the HEASARC in July 2010 based on CDS catalog J/AcA/58/405 file catalog.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassvars
- Title:
- RASS X-Ray Variable Sources Catalog
- Short Name:
- ROSAT/Vars
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The RASS X-Ray Variable Sources Catalog contains the results of a systematic search for variability among the ROSAT All-Sky Survey (RASS) X-ray sources. Lightcurves were generated for about 30,000 X-ray point sources which were detected sufficiently high above the background. For the variability study different search algorithms were developed in order to recognize flares, periods and trends, respectively. The variable X-ray sources were optically identified with counterparts in the SIMBAD, the USNO-A2.0 and NED data bases, but a significant part of the X-ray sources remain without cataloged optical counterparts. A complete list of the 1207 X-ray variable sources that were found is presented in this table. This table was created by the HEASARC in July 2003 based on CDS table J/A+A/403/247/table7.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassaeqso
- Title:
- ROSAT All-Sky Survey/ASIAGO-ESO QSO Survey Catalog
- Short Name:
- RASSAEQSO
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the first results of a survey for bright quasars (V < 14.5 and R < 15.4) covering the northern hemisphere at Galactic latitudes |b| > 30 degrees. The photometric database is derived from the Guide Star and USNO catalogs. Quasars are identified on the basis of their X-ray emission measured in the ROSAT All-Sky Survey (RASS). The surface density of quasars brighter than 15.5 magnitudes turns out to be (10 +/- 2) x 10<sup>-3</sup> degrees<sup>-2</sup>, about 3 times higher than that estimated by the Palomar-Green (PG) survey. In the paper, the quasar optical luminosity function (LF) at 0.04 < z <= 0.3 is computed and shown to be consistent with a luminosity-dependent luminosity evolution of the type derived by La Franca & Cristiani (1997AJ....113.1517L) in the range 0.3 < z <=2.2. The predictions of semianalytical models of hierarchical structure formation agree remarkably well with the present observations. This table was created by the HEASARC in September 2010 based on the combination of the electronic versions of Tables 2, 3, and 4 from the reference paper which were obtained from the CDS (their catalog J/AJ/119/2540). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassbsc
- Title:
- ROSAT All-Sky Survey: Bright Sources
- Short Name:
- RASS/BSC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSAT All-Sky Survey Bright Source Catalog (RASS-BSC, revision 1RXS) was released online at <a href="http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/">http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/</a> (cf. IAU Circular No. 6420, June 19, 1996). It has been superseded by the <a href="/W3Browse/rosat/rass2rxs.html">Second ROSAT All-Sky Survey Point Source Catalog (2RXS)</a>. This catalog was derived from the all-sky survey performed during the first half year of the ROSAT mission in 1990-1991; 18,811 sources are catalogued, with a limiting ROSAT PSPC countrate of 0.05 cts/s in the energy band 0.1- 2.4 keV. The sources have a detection likelihood of at least 15 and contain at least 15 source photons. At a brightness limit of 0.1 cts/s (8547 sources), the catalog represents a sky coverage of 92 percent. The ROSAT name, the position in equatorial coordinates, the positional error, the source countrate and error, the background countrate, exposure time, hardness-ratios HR1 and HR2 and errors, extent and likelihood of extent, and likelihood of detection are provided for each source. For 94 percent of the sources, visual inspection confirmed the results of the standard processing with respect to existence and position; the remaining 6 percent were reanalyzed and appropriately flagged. Broadband images are available for a subset of the flagged sources. This table was originally ingested by the HEASARC in June 1996, based upon the data files from <a href="http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/">http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/</a>. An updated version can be found in the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/IX/10A">CDS Catalog IX/10A</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rasscndins
- Title:
- ROSAT All-Sky Survey Candidate Isolated Neutron Stars
- Short Name:
- RASSCNDINS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Using new and archival observations made with the Swift satellite and other facilities, the authors examine 147 X-ray sources selected from the ROSAT All-Sky-Survey Bright Source Catalog (RASS/BSC) to produce a new limit on the number of isolated neutron stars (INSs) in the RASS/BSC, the most constraining such limit to date. Independent of X-ray spectrum and variability, the number of INSs is <= 48 (90% confidence). Restricting attention to soft (kT<sub>eff</sub> < 200 eV), non-variable X-ray sources - as in a previous study - yields an all-sky limit of <= 31 INSs. In the course of their analysis, the authors identify 5 new high-quality INS candidates for targeted follow-up observations. A future all-sky X-ray survey with eROSITA, or another mission with similar capabilities, can be expected to increase the detected population of X-ray-discovered INSs from the 8 - 50 in the BSC, to (for a disk population) 240 - 1500, which will enable a more detailed study of neutron star population models. Following selection of the INS candidates, short (~ 1 ks) follow-up observations with Swift/XRT were obtained for 92 of the candidates; these observations decreased the X-ray positional uncertainty (the systematic positional error associated with Swift blind pointing observations is on the order of 3.5"). The authors obtained (where possible) contemporaneous UV observations with Swift/UVOT for counterpart identification with off-band objects. This table was created by the HEASARC in May 2012 based on CDS Catalog J/ApJ/714/1424 files table1.dat and table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassfsc
- Title:
- ROSAT All-Sky Survey: Faint Sources
- Short Name:
- RASS/FSC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSAT All-Sky Survey Faint Source Catalog (RASS-FSC) was first released by the Max-Planck-Institut fuer extraterrestrische Physik, Garching group (voges et al. 2000) in May 2000. It is derived from the All-Sky Survey performed during the ROSAT mission using the Position-Sensitive Proportional Counter (PSPC) in the energy range 0.1 to 2.4 keV. Over one hundred thousand (105,924 to be exact) sources are catalogued herein, representing the faint extension of the RASS Bright Source Catalog (RASS-BSC, cf. IAU Circular 6420 and Voges et al. 1999, A&A, 349, 389: this is also available at the HEASARC as the RASSBSC database). The sources in this catalog have a detection likelihood of at least seven, and contain at least six source photons. The likelihood L of source detection is defined as L = -ln (1 - P), where P = the probability of source detection. For each source, the ROSAT name, position and positional error, the source count rate and error, the background count rate, the exposure time, the date of observation, two hardness ratios and their associated errors, the source extent and the extent likelihood, and the likelihood of source detection are given, inter alia. This HEASARC database was created in July 2000 based on the May 26 2000 release of the ROSAT All-Sky Survey Faint Source Catalog obtained from the Max-Planck-Institut fuer extraterrestrische Physik, Garching Website: <a href="http://www.xray.mpe.mpg.de/rosat/survey/rass-fsc/">http://www.xray.mpe.mpg.de/rosat/survey/rass-fsc/</a> 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:
- 10 May 2024
- 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:
- 10 May 2024
- 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:
- 10 May 2024
- 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:
- 10 May 2024
- 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:
- 10 May 2024
- 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/rbs
- Title:
- ROSAT Bright Survey (Schwope et al. 2000)
- Short Name:
- RASS/RBS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSAT Bright Survey (RBS) is an identification program of the more than 2000 X-ray sources at high galactic latitude (absolute latitude b > 30 degrees) with a count rate of more than 0.2 ct/s detected during the ROSAT All-Sky Survey (Voges et al. 1999, A&A, 349, 389). The RBS identification program is more than 99.5% complete. A sub-sample of 931 sources with a count rate of more than 0.2 ct/s in the hard spectral band from 0.5 to 2.0 keV is 100% identified. The total survey area comprises 20391 square degrees at a flux limit of 2.4 x 10<sup>-12</sup> erg/s/cm<sup>2</sup> in the 0.5 to 2.0 keV band. About 1500 sources of the complete sample were identified by correlating the RBS with the SIMBAD and NED databases. The remaining ~500 sources were identified by low-resolution optical spectroscopy and CCD imaging utilizing various telescopes. The RBS Catalog contains optical and X-ray information for each source, including the most massive complete sample of X-ray selected AGN ever assembled, with a total of 669 members, and a well-populated X-ray selected sample of 302 clusters of galaxies with redshifts of up to 0.52. Three X-ray sources in the RBS remain without optical counterparts, RBS 378, RBS 1223, and RBS 1556. While the first is a possible X-ray transient, the latter two sources are isolated neutron star candidates (Motch et al. 1999, A&A, 351, 177; Schwope et al. 1999, 341, L51). As noted elsewhere, this electronic version of the RBS Catalog has a small number of additions/corrections compared to the published version. This database was created by the HEASARC in August 2000 based on a machine-readable table supplied to the HEASARC by Axel Schwope in April 2000. Note that this table is an expanded version of Table 2 in the published paper and contains the following additional parameters: HR2 (hardness_ratio_2), and the Galactic hydrogen column density (nh_21cm). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/wgacat
- Title:
- ROSAT Catalog PSPC WGA Sources
- Short Name:
- WGACAT
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- WGACAT is a point source catalog generated from all ROSAT PSPC pointed observations. This catalog has been generated by N.E. White (HEASARC/GSFC), P. Giommi (SDC/ASI) and L. Angelini (HEASARC/GSFC) and is a private research effort, not related to the official catalogs generated by the ROSAT project. The WGACAT was made first publicly available in November 1994 through the HEASARC on-line service (White, Giommi and Angelini 1994), with a first minor revision in March 1995 (WGACAT95 hereafter). It was generated using all the public ROSAT PSPC pointed data available than, corresponding to 75 % of the entire set, and featured ~ 68000 detections of which 62000 were unique sources. The current version, released in May 2000 (see also the update section), is the final and complete version of WGACAT and includes the remaining sequences not processed in the WGACAT95. WGACAT (May 2000) contains about 88,000 detections, with more than 84,000 individual sources, obtained from 4160 sequences. The catalog was generated using an optimized sliding cell detect algorithm in XIMAGE (first developed for the EXOSAT project). The inner and outer parts of the images were run separately, to maximize the sensitivity to source detection. This method is very sensitive in finding point sources, but can also find spurious sources where there is extended emission. We have visually inspected each detection, removed the obvious spurious cases and assigned a quality flag to each detection. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/roswfc2re
- Title:
- ROSAT Catalog WFC 2RE Sources
- Short Name:
- ROSAT/WFC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSWFC2RE database is the ROSAT Wide Field Camera 2RE Source Catalogue. It contains 479 EUV sources found during the ROSAT all-sky survey of July 1990 to January 1991. The information in this database is based on what will be published by Pye et al. (1995, MNRAS, in press). It supersedes the earlier Bright Source Catalogue (BSC; Pounds et al. 1993, MNRAS, 260, 77). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/roshritotal
- Title:
- ROSAT Complete Results Archive Sources for the HRI
- Short Name:
- ROSAT/HRI
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ROSHRITOTAL data table contains a list of sources detected by the Standard Analysis Software System (SASS) in reprocessed, public HRI datasets. In addition to the parameters returned by SASS (like position, count rate, signal-to-noise, etc.) each source in the table has associated with it a set of source and sequence "flags." These flags are provided by the ROSAT data centers in the US, Germany and the UK to help the user of the ROSHRITOTAL database table quickly judge the reliability of a given source. The ROSHRITOTAL database table is a superset of the ROSHRI database table. The ROSHRI table excludes sources that meet the following parameter criteria: false_det = 'T' or deferred = 'T' or not_checked = 'T' or un_unique ='T'. See the documentation below for descriptions of these parameters. These data have been screened by ROSAT data centers in the US, Germany, and the UK as a step in the production of the ROSAT Results Archive. The RRA contains extracted source and associated products with an indication of reliability for the primary parameters. This database table was last updated in August 2001. More information about the ROSAT Results Archive for HRI sources can be obtained at the following web pages: <pre> <a href="http://heasarc.gsfc.nasa.gov/docs/rosat/rra/RRA.html">http://heasarc.gsfc.nasa.gov/docs/rosat/rra/RRA.html</a> <a href="http://hea-www.harvard.edu/rosat/rra.html">http://hea-www.harvard.edu/rosat/rra.html</a> <a href="http://www.aip.de/groups/xray/rosat/rra.html">http://www.aip.de/groups/xray/rosat/rra.html</a> <a href="http://ledas-www.star.le.ac.uk/rra">http://ledas-www.star.le.ac.uk/rra</a> </pre> This is a service provided by NASA HEASARC .