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BHRFSCID - Byurakan/Hamburg/ROSAT Catalog of Optical IDs

HEASARC
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Overview

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.


Catalog Bibcode

2006A&A...449..425M

References

Optical identification of ROSAT-FSC sources.
    Mickaelian A.M., Hovhannisyan L.R., Engels D., Hagen H.-J., Voges W.
    <Astron. Astrophys. 449, 425 (2006)>
    =2006A&A...449..425M        (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in June 2006 based on CDS table J/A+A/449/425/table1.dat

Parameters

Name
The ROSAT source name in the usual form, e.g., 1RXS Jhhmmss.s+ddmmss.

Error_Radius
The ROSAT positional error, in arcsecs.

Count_Rate
The ROSAT-FSC count rate, in ct/s.

Count_Rate_Error
The uncertainty in the ROSAT-FSC count rate, in ct/s.

Hardness_Ratio_1
The ROSAT HR1 hardness ratio, defined as HR1=(B-A)/(B+A), where A is the count rate in the PHA range 11-41 and B is the count rate in the PHA range 52-201.

Hardness_Ratio_1_Error
The error in the ROSAT hardness ratio HR1.

Hardness_Ratio_2
The ROSAT HR2 hardness ratio, defined as HR1=(D-C)/(D+C), where C is the count rate in the PHA range 52-90and D is the count rate in the PHA range 91-201.

Hardness_Ratio_2_Error
The error in the ROSAT hardness ratio HR2.

Opt_Ctrprt_Component
The optical counterpart component, in cases with >1 counterparts.

RA
The Right Ascension of the DSS2 red counterpart in the selected equinox. This was given in J2000 coordinates to a precision of 0.01 seconds of time in the original table.

Dec
The Declination of the DSS2 red counterpart in the selected equinox. This was given in J2000 coordinates to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the DSS2 red counterpart.

BII
The Galactic Latitude of the DSS2 red counterpart.

Offset
The `distance' (angular offset) between the DSS2 red and X-ray positions, in arcseconds.

Offset_Error_Radius
The `distance' (angular offset) between the DSS2 red and X-ray positions, in terms of the ROSAT positional error.

Maps_Omag
The MAPS O magnitude of the optical counterpart, as measured from the POSS1 blue plate.

Maps_Oe_Color
The MAPS O-E color index of the optical counterpart, using the MAPS O and E magnitudes, as measured from the POSS1 blue and red plates, respectively.

PM_Tot
The USNO-B1.0 total proper motion of the optical counterpart, in mas/yr.

USNO_Omag
The USNO-B1.0 O magnitude of the optical counterpart, being the mean of the DSS1 blue and DSS2 blue magnitudes.

USNO_Emag
The USNO-B1.0 E magnitude of the optical counterpart, being the mean of the DSS1 red and DSS2 red magnitudes.

USNO_Oe_Color
The USNO-B1.0 O-E color index of the optical counterpart, being the mean of the DSS1 O-E and DSS2 O-E colors.

USNO_Imag
The USNO-B1.0 I magnitude of the optical counterpart, i.e., the DSS2 IR magnitude.

Diff_USNO_Mag
The USNO-B1.0 magnitude difference between the DSS2 and DSS1 magnitudes of the optical counterpart, ie., the mean of the blue and red differences.

Source_Type
The general classification of the object based on the DSS images, HQS spectra, MAPS and USNO-B1.0 catalogs, and SIMBAD/NED/AGN/WD/CV associations.

Comments
Comments on the object: e.g., binary and multiple stars, pairs, groups and clusters of galaxies, and QSOs, variability, etc.

Other_Source_Type
The object type, based on its association with a known optical object from SIMBAD, NED, and/or AGN/WD/CV catalogs.

Opt_Name
The name of the optical counterpart object to the X-ray source.

Cat_DSS2_Offset
The `distance' (angular offset) between the catalog position of the optical object and the DSS2 red position measured by the BHRC authors, in arcseconds.

Cat_ROSAT_Offset
The `distance' (angular offset) between the catalog position of the optical object and the ROSAT position, in arcseconds.

Detailed_Source_Type
A more detailed source type for the optical counterpart to the X-ray source, e.g., galaxy or AGN type, or stellar spectral type.

App_Mag
The apparent magnitude of the catalog source, typically the B magnitude.

App_Mag_Band
This parameter indicates the band of the apparent magnitude: B, g or R.

Redshift
The redshift of the catalog source.

Alt_Name_Band
The energy band of other association(s) of the X-ray source with non-optical counterparts: radio, IR, or other X-ray.

Alt_Name
The name of the non-optical counterpart to the X-ray source.

Alt_DSS2_Offset
The `distance' (angular offset) between the catalog position of the non-optical object and the DSS2 red position measured by the BHRC authors, in arcseconds.

Alt_ROSAT_Offset
The `distance' (angular offset) between the catalog position of the non-optical object and the ROSAT position measured by the BHRC authors, in arcseconds.

Class
The HEASARC Browse object classification, based on the detailed_source_type, else the source_type parameter.


Contact Person

Questions regarding the BHRFSCID database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 7-Jun-2006