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   PR # 12204
    We propose to observe the three brightest cooling neutron star candid
    ates PSR B 0656+14, PSR B 1055-52 and Geminga. ROSAT results have
    shown us that these pulsars all emit pulsed, soft, black-body-like
    photons as is expected froma cooling neutron star. However, all three
    also have high-energy tails possibly implying that the magnetospheric
    emission is still active at some level. The  next crucial step is to
    measure the details of the hard-energy tail and try to understand its
    nature and contribution to the reheating of the surface. With the
    proposed exposures,we will be able to determine the parameters of the
    high-energy tails. The GIS count rates are estimated to be about half
    as much as SIS. The good time resolution of the GIS  will also allow
   pulse phase spectroscopy.
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