ISM Chemical Abundances in Two Intermediate-Velocity Clouds in the Line of Sight to SN 1987A

Abstract

The earliest IUE high-resolution spectra of SN 1987A have been studied and reveal the presence of several clouds in the line of sight to the LMC. In particular, there are two clouds with radial velocities of ~ 130 km s^-1^ and ~ 180 km s^-1^. These clouds' velocities are between those of Galactic clouds at 0-80 km s^-1^ and those of LMC gas at ~270 km s^-1^. Chemical-abundance determinations may help to determine the origin and location of these clouds. Curve-of-growth analysis and 21 cm observations show that they may be underabundant in heavy elements by about a factor of 2 as compared to solar abundances. No depletion indicative of grain formation can be seen.