SMCROSXRAY - ROSAT PSPC Survey of the Small Magellanic Cloud

Overview

This catalog presents the results of a systematic search for point-like and moderately extended soft (0.1-2.4 keV) X-ray sources in a raster of nine pointings covering a field of 8.95 square degrees which was performed with the ROSAT PSPC between October 1991 and October 1993 in the direction of the Small Magellanic Cloud (SMC). 248 objects were detected and are included in this first version of the SMC catalog of soft X-ray sources. The authors set up seven source classes defined by selections in the count rate, hardness ratio and source extent parameters. They found five high luminosity super-soft sources (1E 0035.4-7230, 1E 0056.8-7146, RX J0048.4-7332, RX J0058.6-7146 and RX J0103-7254), one low-luminosity super-soft source RX J0059.6-7138 correlating with the planetary nebula L357, 51 candidate hard X-ray binaries including eight bright hard X-ray binary candidates, 19 supernova remnants (SNRs), 19 candidate foreground stars and 53 candidate background active galactic nuclei (and quasars). Likely classifications are given for about 60% of the catalogued sources. The total count rate of the detected point-like and moderately extended sources in the catalog is 6.9 +/- 0.3 counts s^-1, comparable to the background subtracted total rate from the integrated field of about 6.1 +/- 0.1 counts s^-1.

Catalog Bibcode

1999A&AS..136...81K

References

A ROSAT PSPC X-Ray Survey of the Small Magellanic Cloud
       Kahabka P., Pietsch W., Filipovic M.D., Haberl F.
      <Astron. Astrophys. Suppl. Ser. 136, 81 (1999)>
      =1999A&AS..136...81K

Provenance

This online catalog was created by the HEASARC in July 1999 based on tables obtained from the ADC/CDS data centers. It was last updated in October 2025 in order to rename some parameters to conform to HEASARC norms.

Parameters

Catalog_Name
The source designation constructed from the catalog sequential number together with the prefix 'KPF99' recommended by the Dictionary of Nomenclature for this catalog.

Name
The ROSAT source designation.

RA
The right ascension in the selected equinox. The equinox of the positions in the input table for this catalog was J2000.

Dec
The declination in the selected equinox. The equinox of the positions in the input table for this catalog was J2000.

LII
Galactic longitude of the source.

BII
Galactic latitude of the source.

Error_Radius
The 90% confidence positional uncertainty of the X-ray position, in arcseconds.

Count_Rate
The total count rate of the X-ray source in the 0.1-2.4 keV energy range.

Count_Rate_Error
The 1-sigma error of the total count rate.

Hardness_Ratio_1
The soft hardness ratio HR1 = (H-S)/(H+S), where H is the counts in ROSAT PSPC channels 52-201 (energies from 0.5-2.1 keV), and S is the counts in ROSAT PSPC channels 11-41 (0.1-0.4 keV).

Hardness_Ratio_1_Error
The 1-sigma error of the soft hardness ratio.

Hardness_Ratio_2
The hard hardness ratio HR2 = (H2-H1)/(H2+H1), where H1 is the counts in ROSAT PSPC channels 52-90 (energies from 0.5-0.9 keV), and H2 is the counts in ROSAT PSPC channels 91-201 (0.9-2.0 keV).

Hardness_Ratio_2_Error
The 1-sigma error of the hard hardness ratio.

Source_Extent
The source extent of the X-ray source, in arcseconds, in those cases where the likelihood ratio for extent is greater than 10.

Likelihood
The likelihood ratio of existence LH_exist which is related to the probability of existence P by P ~ (1-exp(-LH_exist)). Only sources for which LH_exist > 10 (P > (1 - 4.5 x 10^-5)) are included in this catalog.

Off_Axis
The off-axis angle of the X-ray source, in arcminutes, for the detecttion with the highest LH_exist from the different bands.

Ww_Number
The source number of the corresponding Einstein identification given by Wang & Wu, 1992, ApJS, 78, 391.

Einstein_Offset
The offset, in arcseconds, of the ROSAT PSPC position from the Einstein source position.

Spect_Type
The spectral type of the Simbad-identified star.

App_Mag
The magnitude of the Simbad-identified star.

SIMBAD_Offset
The offset, in arcseconds, of the ROSAT PSPC position from the position of the Simbad-identified star.

Broad_Class
The source classification scheme used in the catalog (more details on how sources were assigned to these classes can be found in Table 3 of the published version of this catalog):

            A: background AGN or quasar
            B: hard X-ray binary
           BL: luminous hard X-ray binary
           BW: weak hard X-ray binary
            D: (possible) artifact
            F: foreground star
            R: supernova remnant or extended structure
            S: super-soft source
           SL: luminous super-soft source
           SW: low-luminosity super-soft source

Refined_Class
A refined source classification for candidate AGN and hard X-ray binaries:

            AB: class A or B (see broad class definitions)
             H: HII region

Note
A note on either the radio or the optical identification.

Class
An approximate browse classification, derived from the value of the broad_class field. Notice that in some cases, the refined_class parameter gives additional or different classification information.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Thursday, 23-Oct-2025 17:53:01 EDT