NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-04-25 T20:04:45 PDT
Help | Comment | NED Home

For refcode 1989ApJS...70..723M:
Retrieve 49 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1989ApJS...70..723M X-RAY MORPHOLOGIES OF ABELL CLUSTERS S. L. W. McMILLAN Department of Physics and Atmospheric Science, Drexel University M. P. KOWALSKI E. O. Hulbert Center for Space Research, Naval Research Laboratory AND M. P. ULMER Department of Physics and Astronomy, Northwestern University Received 1988 September 6; accepted 1988 December 12 ABSTRACT We have determined the orientations and ellipticities of the X-ray images of a sample of 49 Abell clusters. The techniques used in determining the level of noise in the images (and removing it) are described, and a variety of approaches to the problem of defining reliable cluster morphological parameters are discussed and compared. For each cluster, we (1) determine overall parameters (using the faintest flux levels) and (2) investigate the variation of those parameters with flux level. We find that around one-half of the cluster images show unambiguous elongation, approximately one-quarter exhibit isophotal twisting, and the remaining 25% are either too irregular or too uncertain to allow definitive statements to be made. A short catalog of cluster properties is presented, and some of the clusters with significant substructure are discussed in more detail. The results of this study are applied to the question of large-scale cluster alignments in a separate paper. Subject headings: galaxies: clustering - galaxies: X-rays
Retrieve 49 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home