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   52085
   A large fraction of heavy elements in the interstellar medium (ISM) is
   depleted onto dust grains. When the ISM is shocked by a supernova blast
   wave, grains are suddenly immersed in hot plasmas of supernova remnants
   (SNRs), and emit strongly in the infrared (IR). They are also gradually
   destroyed through sputtering, which reduces thermal dust emission. The
   Infrared Space Observatory (ISO) is currently providing crucial data on
   dust destruction in selected SNRs. X-ray spectra of these SNRs are
   expected to be strongly affected by depletion of elements onto grains.
   Because of dust destruction, one expects strong spatial anti-
   correlation of IR and X-ray emission. In order to study dust
   destruction in the ISM, we propose ASCA observations of RCW 86, a
   target of a similar investigation with ISO
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