SUMMARY OF PROPOSAL 43044
DR. MONIQUE ARNAUD
CEA SACLAY
 FRANCE 91191
GIF-SUR-YVETTE
L'ORME DES MERISIERS, BAT 709

  E-mail: ARNAUD@SAPVXG.SACLAY.CEA.FR	Tel: 33 1 69 08 20 41	Fax: 33 1 69 08 65 77
  Medium: 2GB8MM

Subject: CLUSTERS OF GALAXIES AND SUPERCLUSTERS                      
  Title: OBSERVATION OF A 521, A LENSING GALAXY CLUSTER: TEMPERATURE AND MASS DETERMINATION


Abstract:
 The masses and profiles (for both the visible and dark components) in galaxy
 clusters, as well as their dynamical state, are key cosmological issues. X-Ray
 bright clusters where gravitational lensing occurs are favoured laboratories for
 such studies: X-ray observations provide total mass estimates through the
 hydrostatic equation whereas lensing data are mass estimators, independant of the
 dynamical state. We propose to perform a 50 ksec ASCA observation of the lensing
 cluster A521 to obtain the essential temperature information. The ASCA data will be
 combined with ROSAT/HRI imagery data, optical (photometry and multi-object
 spectroscopy) data and lensing data to study the consistency between the various
 mass estimates and to probe the galaxies and ICM dynamical states.

 Co-Is:
   1  ROBERT ROTHENFLUG   	CEA SACLAY                    FRANCE    
      ROTHENFLUG@SAPVXG.SACLAY.CEA.FR	33 1 69 08 43 27
   2  JEAN-LUC SAUVAGEOT  	OSAKA UNIVERSITY              JAPAN     
   3  KOUJUN YAMASHITA    	NAGOYA UNIVERSITY             JAPAN     
   4  SOPHIE MAUROGORDATO 	MEUDON OBSERVATORY            FRANCE    
   5  DOMINIQUE PROUST    	MEUDON OBSERVATORY            FRANCE    


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
A 521                  1   73.5500  -10.2500    50   N   Y   P  0.11000   1