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   PR # 42169
   We propose to conduct coordinated ASCA x-ray observations of two
   southern gamma-ray blazars, each a prototypical member of its class:
   the nearby x-ray-selected BL Lac PKS 2155-304, newly-discovered as a
   gamma-ray source during our current CGRO Cycle 4 observing program,
   and the bright, variable gamma-ray quasar PKS 0208-512. The proposed
   ASCA observations will be carried out in conjunction with an
   international campaign to acquire simultaneous measurements from GHz
   radio frequencies, including VLBI mapping, to GeV gamma-ray energies
   (TeV energies for 2155-304); these will provide ``snap-shots'' of the
   spectral energy distribution in the sources and, in the event of a
   strong flare, can serve to map out in time and space the structure of
   the blazar jet.
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