Detection of highly ionized CIV gas within the Local Cavity
  We present high resolution (R = 114,000) ultraviolet measurements of the
interstellar absorption line profiles of the CIV (1550 A) high ionization
doublet recorded towards the nearby B2Ve star HD 158427 (d~74pc). These data,
which were recorded with the recently re-furbished STIS instrument on the HST,
represent the most convincing detection yet of highly ionized CIV absorption
that can be associated with interstellar gas located within the boundary of the
Local Cavity. Two highly ionized gas clouds at V1 = -24.3 km/s and V2 = -41.3
km/s are revealed in both CIV absorption lines, with the V1 component almost
certainly being due to absorption by the Local Interstellar Cloud (d<5pc).
Although the observed column densities for both cloud components can be
explained by the predictions of current theoretical models of the local
interstellar medium, the narrow doppler width of the V2 line-profile (b = 6.8
km/s) indicates an unusually low gas temperature of less than 34,000K for this
highly ionized component. It is conjectured that the V2 cloud may be due to an
outflow of highly ionized and hot gas from the nearby Loop I superbubble. These
new data also indicate that absorption due to highly ionized gas in the Local
Cavity can be best described as being 'patchy' in nature.
