  We report on the properties of LISM O VI absorption observed with 20 km/s
resolution FUSE observations of 39 white dwarfs (WDs) ranging in distance from
37 to 230 pc with a median distance of 109 pc. LISM O VI is detected with
>2sigma significance along 24 of 39 lines of sight. The column densities range
from log N(O VI) = 12.38 to 13.60 with a median value of 13.10. The line of
sight volume density, n(O VI) = N(O VI)/d exhibits a large dispersion ranging
from (0.68 to 13.0)x10(-8) cm(-3) with an average value 3.6x10(-8) cm(-3) twice
larger than found for more distant sight lines in the Galactic disk. The
narrowest profiles are consistent with thermal Doppler broadening of O VI near
its temperature of peak abundance, 2.8x10(5) K. Comparison of the average
velocities of O VI and C II absorption reveals 10 cases where the O VI
absorption is closely aligned with the C II absorption as expected if the O VI
is formed in a condensing interface between the cool and warm absorption and a
hot exterior gas. The comparison also reveals 13 cases where O VI absorption is
displaced to positive velocity by 7 to 29 km/s from the average velocity of C
II. The positive velocity O VI appears to be tracing the evaporative flow of O
VI from a young interface between warm gas and a hot exterior medium. However,
it is possible the positive velocity O VI is instead tracing cooling hot Local
Bubble (LB) gas. The properties of the O VI absorption in the LISM are broadly
consistent with the expectations of the theory of conductive interfaces caught
in the old condensing phase and possibly in the young evaporative phase of
their evolution.
