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Einstein x ray observations of the core of the Shapley Supercluster in northern CentaurusWe present Einstein x ray observations of the core of the Shapley Supercluster, one of the richest and densest known mass concentrations in the local (z less than 0.1) universe. We used Imaging Proportional Counter (IPC) observations supplemented with data from the Einstein Slew Survey to determine the locations and structure of mass concentrations in the region. An x ray map composed of IPC observations of the central (10 deg x 10 deg) region of the Shapley Supercluster is presented. We present evidence that the X-ray clusters observed within 5 deg of the core of the supercluster are on average brighter than those of corresponding richness class distributed throughout the sky. However, we measure no significant difference in the galaxy formation efficiency of these cluster of galaxies compared to other, more isolated clusters. We also find one previously uncataloged cluster-sized mass concentration in the core of the Shapley Supercluster. This new cluster, 'SC 1327-312', is relatively x ray bright (F(sub x) = 1.1 + or - 0.2 x 10(exp -11) erg sec(exp -1) cm(exp -2)) and L(sub x) = 1.1 + or - 0.2 x 10(exp 44) erg sec(exp -1) within 10 minutes, assuming z = 0.0477, H(sub 0) = 50, q(sub 0) = 0). As SC 1327-312 lies well within an Abell radius of the richness R = 4 cluster Shapley 8 (A3558), we suggest it may contribute to an artificially high galaxy count and richness classification for shapley 8. From slew data, we estimate an x ray luminosity for Shapley 8 which is just half the mean luminosity of the four other R = 4 clusters observed by the IPC, further suggesting the richness classification to be an overestimate.
Document ID
19950034521
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Breen, Jeffrey (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Raychaudhury, Somak (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Forman, William (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Jones, Christine (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Date Acquired
August 16, 2013
Publication Date
March 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 424
Issue: 1
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAG5-1204
Distribution Limits
Public
Copyright
Other