- ID:
- ivo://nasa.heasarc/rass6dfgs
- Title:
- ROSAT All-Sky Survey/6dF Galaxy Survey Catalog of X-Ray Selected AGN
- Short Name:
- RASS6DFGS
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of 3405 X-ray sources from the ROSAT All Sky Survey (RASS) Bright Source Catalog which fall within the area covered by the 6dF Galaxy Survey (6dFGS). The catalog is count-rate limited at 0.05 ct s<sup>-1</sup> in the X-ray and covers the area of sky with Declination < 0 degrees and |b| > 10 degrees. The RASS-6dFGS sample was one of the additional target catalogs of the 6dFGS and as a result the authors obtained optical spectra for 2224 (65 per cent) RASS sources. Of these, 1715 (77%) have reliable redshifts with a median redshift of z = 0.16 (excluding the Galactic sources). For the optically bright sources (b_J <= 17.5) in the observed sample, over 90% have reliable redshifts. The catalog mainly comprises quasi-stellar objects (QSOs) and active galaxies but also includes 238 Galactic sources. Of the sources with reliable redshifts, the majority are type 1 active galactic nuclei (AGN, 69%), while 12% are type 2 AGN, 6% absorption-line galaxies and 13% are stars. The authors also identify a small number of optically faint, very low redshift, compact objects which fall outside the general trend in the b_J - z plane. The RASS-6dFGS catalog complements a number of Northern hemisphere samples, particularly the ROSAT Bright Source Catalogue-NRAO VLA Sky Survey (RBSC-NVSS) sample (Bauer et al. 2000, ApJS, 129, 547), and furthermore, in the same region of sky (-40 degrees < Declination < 0 degrees) reveals an additional 561 sources that were not identified as part of that sample. The authors detect 918 sources (27%) of the RASS-6dFGS sample in the radio using either the 1.4 GHz NVSS or the 843 MHz Sydney University Molonglo Sky Survey (SUMSS) catalogues and find that the detection rate changes with redshift. At redshifts larger than 1 virtually all of these sources have radio counterparts and with a median flux density of 1.15 Jy, they are much stronger than the median flux density of 28.6 mJy for the full sample. The authors attribute this to the fact that the X-ray flux of these objects is being boosted by a jet component, possibly Doppler boosted, that is only present in radio-loud AGN. The RASS-6dFGS sample provides a large set of homogeneous optical spectra ideal for future studies of X-ray emitting AGN. This table was created by the HEASARC in April 2010 based on an electronic version of Table 3 from the reference paper obtained from the MNRAS web site. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/rassfsc
- Title:
- ROSAT All-Sky Survey: Faint Sources
- Short Name:
- RASS/FSC
- Date:
- 18 Apr 2025
- 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:
- 18 Apr 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/rasshgsoft
- Title:
- ROSAT All-Sky Survey: Soft High Galactic-Latitude X-Ray Sources
- Short Name:
- RASS/Soft
- Date:
- 18 Apr 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/rasshgsft2
- Title:
- ROSAT All-Sky Survey: Soft High Galactic-Latitude X-Ray Sources 2
- Short Name:
- RASSHGSFT2
- Date:
- 18 Apr 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/rass2foid
- Title:
- ROSAT All-Sky Survey Two Selected Fields Optical Identifications Catalog
- Short Name:
- RASS2FOID
- Date:
- 18 Apr 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:
- 18 Apr 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/rbs
- Title:
- ROSAT Bright Survey (Schwope et al. 2000)
- Short Name:
- RASS/RBS
- Date:
- 18 Apr 2025
- 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:
- 18 Apr 2025
- 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:
- 18 Apr 2025
- 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 .
