HRASSOPTID - Hamburg/RASS Catalog: Optical Identifications
The Hamburg/RASS Catalogue of optical identifications. Northern high-galactic latitude ROSAT Bright Source Catalogue X-ray sources. Zickgraf F.-J., Engels D., Hagen H.-J., Reimers D., Voges W. <Astron. Astrophys. 406, 535 (2003)> =2003A&A...406..535Z
The catalog can be used for scientific purposes if the paper listed in the References section is referenced. For more detailed information about the identification code and the classification scheme for objective prism spectra, the catalog user is also referred to this paper.
The research on which this table is based made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. It has been funded by the Deutsche Forschungsgemeinschaft under Re 353/22-1 to 4 and by the BMBF under DARA 50 0R 96016.
The STScI Digitized Sky Surveys were produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. The National Geographic Society - Palomar Observatory Sky Atlas (POSS-I) was made by the California Institute of Technology with grants from the National Geographic Society.
The name of the proposed or possible optical counterpart to the X-ray source, using the naming convention recommended by the Dictionary of Nomenclature of Celestial Objects.
The name of the X-Ray source, using the original ROSAT All-Sky Survey designation.
This parameter is a flag which is set to 'Y' to indicates that this object is the proposed Optical counterpart to the X-ray source, else it is set to 'N'. (In the published and CDS versions of the HRC, the values were '+' and ' ', respectively).
The running number of the optical object(s) that were visible within the error circle of the X-ray source.
The Right Ascension of the optical object in the selected equinox. This was given in J2000.0 coordinates and to a precision of 0.1 seconds of time in the original catalog. Two of the objects in the latter, '[ZEH2003] RX J1714.7+6442 2' and '[ZEH2003] RX J0138.5+2458 2', had blank ra and dec values: in this HEASARC table, we have placed these objects at the positions implied by their X-ray names.
The Declination of the optical object in the selected equinox. This was given in J2000.0 coordinates and to a precision of 1 arcsecond in the original catalog. Two of the objects in the latter, '[ZEH2003] RX J1714.7+6442 2' and '[ZEH2003] RX J0138.5+2458 2', had blank ra and dec values: in this HEASARC table, we have placed these objects at the positions implied by their X-ray names.
The Galactic Longitude of the optical object.
The Galactic Latitude of the optical object.
The Right Ascension offset, in arcseconds, between the X-Ray position and the position of the optical counterpart.
The Declination offset, in arcseconds, between the X-Ray position and the position of the optical counterpart.
The total offset, in arcseconds, between the X-Ray position and the position of the optical counterpart.
This parameter is a flag which indicates a limit on the B magnitude of the optical object.
The B magnitude of the optical object. B photometry was usually taken from the Hamburg Quasar Survey (HQS: Hagen et al. 1995, A&AS, 111, 195). The HQS B magnitudes are calibrated in the Johnson system. In the cases of bright stars, however, the HQS photometry, based on the low-resolution scans of the prism plates, did not allow the B magnitude to be measured because of the spectra being saturated. The USNO Catalog was then searched, in such cases, for the corresponding entry, and the USNO B magnitude was adopted if a matching entry was found within 5 arcseconds. This was not always the case, due to proper motion effects, and the search radius was then enlarged to 10 arcseconds. (In such cases, the value of the bmag_flag parameter has been set to 'p'). If no match was found even within 10 arcseconds, only a limit of <10.0 is given for the object's B magnitude. Occasionally, source confusion caused problems in the automatic assignment of B magnitudes from the HQS for a faint object located close to brighter objects. In order to detect these cases, the authors compared their B magnitudes with those in the USNO Catalog, and substituted USNO values if the HQS magnitude was brighter by at least 0.7 magnitudes. In such cases, the value of the bmag_flag parameter has been set to 'u'. A correction of +0.4 was applied to the USNO magnitudes in order to transform the photographic O magnitudes of the USNO to Johnson B.
This parameter is a flag indicating a note about the B magnitude of the optical object: 'u' means that the B magnitude was taken from the USNO Catalog, 'e' means that the object was extended, 'p' means that the B magnitude was also taken from the USNO Catalog, but that, since the object has a high proper motion, the USNO - HRC matching radius which was used was 10" rather than 5", and ':' means that the B magnitude is uncertain.
The B-R color index of the optical object, taken from the USNO-A2.0 Catalog (CDS Catalog <I/252>).
The classification of the optical object based on the objective prism spectra, according to the following scheme:
SUBDWARF Hot Subdwarfs (sdO,sdB) W-DWARF White Dwarfs STAR-BA Balmer absorption lines, point-like image STAR-FG G-Band, Ca H+K, point-like image STAR-K G-Band, Ca H+K, redder continuum, point-like image STAR-M Very red, TiO lines, Ca I 4226, point-like image CV Cataclysmic variable, Balmer emission lines GALAXY Extended image on direct plate, no emission lines, red continuum AGN Emission line(s), blue continuum, weak extension on direct plate allowed BLUE GAL moderately blue continuum, extended image on direct plate QSO Emission line(s), extremely blue continuum, no extension on direct plate EBL-WK Extremely blue continuum, weak point-like object BLUE-WK Moderately blue continuum, weak point-like object RED-WK Red continuum, weak point-like object UNIDENT Classification open OVERLAP Classification not possible due to overlapping spectra SATURATE Classification not possible due to amplifier saturation
In the case of the object '[ZEH2003] RX J1116.2+4942 3', the value of this parameter in the original CDS table was 'ED-WK', and the HEASARC has changed this to 'RED-WK', assuming it was a transcription error.
A note when no position is given for the optical object.
The HEASARC Browse object classification, based on the value of the spectral_id parameter.