Tiny HI Clouds in the Local ISM

Abstract

Very sensitive HI absorption spectra (tau RMS about 10^-4 over 1 km/s) toward high latitude QSOs have revealed a population of tiny discrete features in the diffuse ISM with peak tau of 0.1 - 2% and core line-widths corresponding to temperatures as low as 20 K. Imaging detections confirm linear dimensions of a few 1000 AU. We suggest these structures may be formed by the stellar winds of intermediate mass stars. A more speculative origin might involve molecular "dark matter".

6 pages, 8 figures, to appear in "The IMF at 50", eds. E. Corbelli, F. Palla, and H. Zinnecker, ASSL (Kluwer)

References in corpus (2)

• Thermal condensation in a turbulent atomic hydrogen flow
• The Complex Interstellar Na I Absorption toward h and Chi Persei

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