******************************************************
   PR # 12080
      A number of accretion-powered X-ray sources show clear evidence of
    discrete emission. However, the nature of this emission, particularly
    in the soft X-ray band, is uncertain. Most of the ambiguity can be
    traced to the coupled effects of poor counting statistics and the
    failure of plasma emission models to adequately reproduce the data.
    We propose to obtain high-quality spectroscopic data from the low-
    mass X-ray binary GX9+9, which is known to exhibit substantial
    discrete spectral structure, and to interpret this data in light of
    detailed spectral models which account for the atomic processes
    peculiar to X-ray photoionized plasmas.


 ******************************************************