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   PR # 22133
    We propose to observe three isolated, high luminosity early-type     
    galaxies -- NGC 533, NGC 1600, and NGC 3557 -- for 20, 40, and 40    
    ksec, respectively. By analyzing SIS and GIS spectra to measure      
    temperatures, abundances of Fe and other elements, and hydrogen      
    column densities we can constrain the amount of dark matter, the SNIa
    rate, and the amount of matter deposited by a cooling flow. Spectral 
    and imaging analysis will enable us to further our understanding of  
    the hard spectral component seen in BBXRT and the PV phase. A primary
    goal is to investigate how the above properties depend on the optical
    characteristics of the galaxies and their environments.              
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