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BHRFSCID: Help

BHRFSCID - Byurakan/Hamburg/ROSAT Catalog of Optical IDs


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.
If you have any problems, please consult the help page or mail ledas-help@star.le.ac.uk
 
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