******************************************************
   PR # 12069
    While starburst galaxies are popular candidates for the origin of the
    unresolved X-ray background, uncertainties about the nature of their
    spectra above 3 keV and their luminosity evolution still need to be
    resolved.  Our recent confirmation that two luminous X-ray sources
    (L$_{\rm X}$ $>$ $10^{42}$ erg s$^{-1}$)are indeed starbursts greatly
    enhances the viability of starbursts as significant XRB contributors,
    but opens new questions as to the mechanisms for this extreme high
    energy production.  ASCA spectra will unambiguously reveal important
    clues about the violent processes occurring within these galaxies and
    if they have hard X-ray spectra required to solve the problem of the
    XRB.

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