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ROSGALCLUS - ROSAT PSPC Catalog of Clusters of Galaxies

HEASARC
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Overview

This is a catalog of 203 clusters of galaxies serendipitously detected in 647 ROSAT PSPC high Galactic latitude pointings covering 158 square degrees. This is one of the largest X-ray-selected cluster samples, comparable in size only to the ROSAT All-Sky Survey sample of nearby clusters (Ebeling et al. 1997). Clusters in the inner 17.'5 of the ROSAT PSPC field of view are detected using the spatial extent of their X-ray emission. Fluxes of detected clusters range from 1.6 x 10^-14 to 8 x 10^-12 ergs s^-1 cm^-2 in the 0.5-2 keV energy band. X-ray luminosities range from 10^42 ergs s^-1, corresponding to very poor groups, to ~5 x 10^44 ergs s^-1, corresponding to rich clusters. The cluster redshifts range from z = 0.015 to z > 0.5. The catalog lists X-ray fluxes, core radii, and spectroscopic redshifts for 73 clusters and photometric redshifts for the remainder. Of 223 X-ray sources, 203 have been optically confirmed as clusters of galaxies. Of the remaining 20 sources, 19 are likely false detections arising from blends of unresolved point X-ray sources. Optical identifications of the remaining object are hampered by a nearby bright star. Above a flux of 2 x 10^-13 ergs s^-1 cm^-2, 98% of extended X-ray sources are optically confirmed clusters. The number of false detections and their flux distribution are in perfect agreement with simulations. The log N-log S relation for clusters derived from this catalog shows excellent agreement with counts of bright clusters derived from the Einstein Extended Medium Sensitivity Survey and the ROSAT All-Sky Survey. At fainter fluxes, its log N-log S relation agrees with the smaller area WARPS survey. The cluster counts appear to be systematically higher than those from a 50 square degree survey by Rosati et al.

Catalog Bibcode

1998ApJ...502..558V

References

Vikhlinin, A., McNamara, B. R., Forman, W., Jones, C., Quintana, H., and Hornstrup, A. 1998, ApJ, 502, 558; bibcode = 1998ApJ...502..558V

Provenance

This database was created by the HEASARC in December 2001 based on the CDS/ADC catalog J/ApJ/502/558/ (table3.dat).

Parameters

Name
The name of the cluster of galaxies using the prefix 'VMF98' recommended by the Dictionary of Nomenclature of Celestial Objects and the running number given in the published paper (and CDS table).

RA
The Right Ascension of the cluster of galaxies in the selected equinox. This was given in J2000 coordinates and to a precision of 0.1 seconds of time in the originating table.

Dec
The Declination of the cluster of galaxies in the selected equinox. This was given in J2000 coordinates and to a precision of 1 arcsecond in the originating table.

LII
The Galactic Longitude of the cluster of galaxies.

BII
The Galactic Latitude of the cluster of galaxies.

Flux
The total unabsorbed X-ray flux in the 0.5 - 2 keV energy band (observer frame), in units of erg s^-1 cm^-2.

Flux_Error
The RMS uncertainty in the total unabsorbed X-ray flux in the 0.5 - 2 keV energy band (observer frame), in units of erg s^-1 cm^-2.

Core_Radius
The angular core radius, in arcseconds.

Core_Radius_Error
The RMS uncertainty in the angular core radius, in arcseconds.

Redshift
The heliocentric spectroscopic or photometric redshift.

Min_Redshift
The minimum value of the 90% confidence interval of the photometric redshift. If the redshift value given is spectroscopic, no value is given for this parameter.

Max_Redshift
The maximum value of the 90% confidence interval of the photometric redshift. If the redshift value given is spectroscopic, no value is given for this parameter.

Dss_Redshift_Flag
This parameter is set to 'DSS' for the 7 clusters for which the Digitized Sky Survey (DSS) was used to obtain the photometric redshift.

Error_Radius
The angular radius of the 90% X-ray position error circle, in arcseconds.

Uncertainty_Flag
This parameter has two possible non-null values: 'F' is used to indicate a likely false detection, while 'U' is used for three clusters which show clear concentrations of galaxies near the X-ray position, but for which the choice of brightest cluster galaxy is uncertain because of the large angular size of the cluster.

Note_Flag
A reference number to a note according to the following rubric:

  Value    Note

   1     J1888.16 cluster, z=0.563
   2     A122, z=0.11278
   3     Abell S154
   4     APMBGC 244-064-098, z=0.08764
   5     A227, z=0.17625
   6     A3038
   7     Abell S346, z=0.067
   8     A3259
   9     A744, z=0.0756
  10     2' of PDCS 040
  11     A899
  12     J101016.1+543006 group, z=0.045
  13     z=0.340 cluster (Schmidt et al., 1998A&A...329..495S)
  14     UGC 06057 group, z=0.0382
  15     MS 1157.3+5548, z=0.081
  16     MS 1201.5+2824, z=0.167
  17     MS 1208.7+3928, z=0.340
  18     MS 1308.8+3244, z=0.245
  19     MKW 11, z=0.02314
  20     z=0.308 cluster (McHardy et al., 1998MNRAS.295..641M)
  21     z=0.382 cluster (McHardy et al., 1998MNRAS.295..641M)
  22     RX J13406+4018 group, z=0.171
  23     A1774, z=0.1691
  24     A1775, z=0.0696
  25     Probably part of A1877, z=0.2493
  26     Image saturated by a nearby star
  27     A1969, z=0.29809
  28     Distant cluster behind the nearby group
  29     MCG +04-39-010 group
  30     A2220, z=0.1106
  31     TTR95 1646+82 cluster
  32     QSO 1640+400, z=1.59
  33     A2246, z=0.225
  34     Abell S840, z=0.0152
  35     UGC 11780 group
  36     Part of A2465, z from Jones et al. (1995, in MPE Report 263, 591)
  37     Part of A2465, z from Jones et al. (1995, in MPE Report 263, 591)
  38     Zw2255.5+2041, z=0.288
  39     A4043
  

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 8-Nov-2004