SUMMARY OF PROPOSAL 42189
DR. DAVID S. DAVIS
UNIVERSITY OF ALABAMA
AL USA 35487
TUSCALOOSA
206 GALLALEE HALL

  E-mail: DAVIS@HERA.ASTR.UA.EDU	Tel: 205-348-4593	Fax: 205-348-5050
  Medium: 4GBDAT

Subject: CLUSTERS OF GALAXIES AND SUPERCLUSTERS                      
  Title: ASCA OBSERVATIONS OF MODERATE Z MEDIUM LUMINOSITY SYSTEMS                       


Abstract:
 Cluster mergers are thought to drive the X-ray evolution of clusters, but to fully
 understand these events we need to study young mergers. Classical signatures of a
 merger can last for up to 10$^9$ yrs. Radio halos, which are thought to be short
 lived (<10$^8$ yrs), are now thought to be powered by mergers. This makes these
 halos ideal indicators of a young merger. Furthermore, irregular radio halos are
 thought to be much younger than symmetric halos. The clusters with irregular radio
 halos and high quality X-ray data (A2256 & A754) have had anomalously hot gas (kT >>
 8.5 keV) detected in them. We propose to obtain ASCA data for the recent-merger
 candidate A2255, a cluster with an irregular radio halo and evidence from the PSPC data of an anomalously hot component.

 Co-Is:
   1  RAYMOND WHITE       	U OF ALABAMA                  USA       
      WHITE@MERKIN.ASTR.UA.EDU	205-348-1640


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
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