HST/STIS observations of the high-velocity interstellar cloud HVC 291.2-41.2+80: a warm, mainly ionized high-velocity cloud

We present intermediate-resolution HST/STIS spectra of a high-velocity inte rstellar cloud ((LSR)-L-upsilon = + 80 kms(-1)) towards DI1388, a young sta r in the Magellanic Bridge located between the Small and Large Magellanic C louds. The STIS data have a signal-to-noise ratio (S/N) of 20-45 and a spec tral resolution of about 6.5 km s(-1) (FWHM), The high-velocity cloud absor ption is observed in the lines of C II, O I, Si II, Si III, Si IV and S III . Limits can be placed on the amount of S II and Fe II absorption that is p resent. An analysis of the relative abundances derived from the observed sp ecies, particularly C II and O I, suggests that this high-velocity gas is w arm (T-k similar to 10(3)-10(4) K) and predominantly ionized, This hypothes is is supported by the presence of absorption produced by highly ionized sp ecies, such as Si IV, This sightline also intercepts two other high-velocit y clouds that produce weak absorption features at (LSR)-L-upsilon = + 113 a nd + 130kms(-1) in the STIS spectra.