  We present first results from simultaneous ultraviolet (UV; HST/GHRS) and
X-ray (ASCA) observations of the 13.5s pulsar LMC X-4 taken in 1996 May. The
GHRS data are the highest resolution (both temporal and spectral) UV spectra
ever taken of LMC X-4. Fits to the UV continuum using a model that incorporates
X-ray heating of the companion star and the accretion disk yields a mass
accretion rate Mdot=4.0x10^(-8) Msun/yr; the X-ray luminosity implied by this
value is consistent with the X-ray flux measured during simultaneous
observations. The model accurately predicts observed B magnitude and
ultraviolet variations over both orbital and long-term periods. The UV P-Cygni
lines show dramatic changes with orbital phase: strong broad absorption near
X-ray eclipse and narrow absorption when the X-ray source is in the
line-of-sight. We interpret this as a result of X-ray photoionization of the
stellar wind; when the neutron star is in front of the normal star, the wind
absorption disappears and mainly the photospheric absorption lines are visible.
The X-ray pulse period measured during our observations, 13.5090+/-0.0002s, is
consistent with steady spin-down over the past 10 years. No pulsations were
detected in the UV observations with upper limits to the pulsed fraction around
N V and C IV of 1.8% and 2.7% in the continuum and 12.4% and 7% in the
absorption troughs.
