RASSBSC - ROSAT All-Sky Survey: Bright Sources

Overview

The ROSAT All-Sky Survey Bright Source Catalog (RASS-BSC, revision 1RXS) was released online at http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/ (cf. IAU Circular No. 6420, June 19, 1996). It has been superseded by the Second ROSAT All-Sky Survey Point Source Catalog (2RXS).

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.

Catalog Bibcode

1999A&A...349..389V

References

The ROSAT all-sky survey bright source catalogue.
    Voges W., Aschenbach B., Boller T., Braeuninger H., Briel U., Burkert W.,
    Dennerl K., Englhauser J., Gruber R., Haberl F., Hartner G., Hasinger G.,
    Kuerster M., Pfeffermann E., Pietsch W., Predehl P., Rosso C.,
    Schmitt J.H.M.M., Truemper J., Zimmermann H.U.
   <Astron. Astrophys. 349, 389 (1999)>
   =1999A&A...349..389V

Provenance

This table was originally ingested by the HEASARC in June 1996, based upon the data files from http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/. An updated version can be found in the CDS Catalog IX/10A.

Parameters

Name
The ROSAT All-Sky Survey source designation.

RA_B1950
The Right Ascension in 1950 coordinates.

Dec_B1950
The Declination in 1950 coordinates.

RA
The source RA (displayed in the specified equinox).

Dec
The source Dec (displayed in the specified equinox).

LII
The Galactic longitude of the source.

BII
The Galactic latitude of the source.

Positional_Error
The error on the position given in arcseconds. (This includes a 6-arcsecond systematic error.)

Screen_Flag
Screening flags.

New_Data_Flag
The new data flag is a 4-character string composite of 4 flags (RIV?), each indicating additional screening criteria.

    R: source counts and extracted radius recalculated
    I: broad band image available (images are not available at HEASARC)
    V: variability flag (not populated)
    ?: dummy flag

Each character (flag) in the string can have the following values: 'T' for true, 'F' or '_' for false, and '.' for 'not used'.

Count_Rate
The source count rate, with vignetting corrected, in the PHA range 11-235.

Count_Rate_Error
The error on count rate vignetting corrected. If this field is set to zero, that means the error has not been determined.

Background_Count_Rate
The background count rate, vignetting corrected, in counts/sec/arcmin².

Exposure
The exposure time of field, in seconds.

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

Hardness_Ratio_1_Error
The hardness ratio 1 error.

Hardness_Ratio_2
The hardness ratio defined as HR2=(D-C)/(D+C), where C are the counts in the PHA range 52-90 and D are the counts in the PHA range 91-201.

Hardness_Ratio_2_Error
The hardness ratio 2 error.

Source_Extent
The amount is specified, by which the source image exceeds the point spread function. The value is given in arcsec.

Extent_Likelihood
The likelihood of source extent. If the value is greater than 9999, it has been set to 9999.

Detect_Likelihood
The likelihood of source detection algorithm. If the value is greater than 9999, it has been set to 9999.

Extraction_Radius
The source extraction radius in arcsec. If the value is greater than 9999 (e.g. Vela SNR), it has been set to 9999.

Priority_Flags
The priority flag is a string composite of 6 characters, each indicating the following flags:

    M-broad
    L-broad
    M-hard
    L-hard
    M-soft
    L-soft

Sliding window detection history using either the background map (M) or the local background (B): 0 = no detection, 1 = detection.

High_Detect_Range
The PHA range with the highest detection likelihood.

Vignetting_Factor
The telescope vignetting correction (1 = on-axis; lower than 1 = off-axis)

Date_Included
Date when source was included. Format: yymmdd; 000000: removed.

Date_Modified
Date when source properties were changed. Format: yymmdd; 000000: not changed.

SASS_Field_ID
Identification number of the SASS field. An overview of the field structure is available at the URL http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/sup/psplit.ps.gz.

SASS_Source_Number
The SASS source number (MASOL number) in the SASS field.

Contact Person

Questions regarding the RASSBSC database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Thursday, 19-Sep-2024 13:49:41 EDT