Distribution and kinematics of MgII in the LISM

Abstract

We have analyzed MgII emissions in the IUE spectra of 91 cool stars in a systematic search for interstellar components. 60% of the stars show evidence of interstellar contamination. The radial velocities of the IS features show that even at short distances (d < 30 pc) the motion of the LISM agrees with that derived from the analysis of optical IS absorptions in the directions of more distant stars. The absence of detectable interstellar lines has allowed us to derive stringent upper limits along the line of sight of many stars. The results suggest that the density of the gas in the immediate vicinity of the sun may be lower than previously estimated. In particular, the presence of the low density region towards the northern galactic pole around HZ43 is confirmed.