Published in "The Interstellar Medium in Galaxies", eds. H. A. Thronson, Jr. and J. M. Shull, 1990.

For a postscript version of the article, click here.

Abstract. The purpose of this review is to discuss high resolution HI observations of a sample of nearby galaxies and to explain what they can teach us about the composition, structure and energy balance of the Interstellar Medium or ISM. The first part presents a summary of what is known about the ISM of the Galaxy and is followed by an overview of the current theoretical models. It continues by showing that it has become feasible to extend studies of the local ISM to nearby spirals, thus avoiding the well known problems associated with Galactic studies such as distance ambiguities and line of sight confusion. The second part is devoted to a discussion of the individual galaxies, addressing both the global properties of the ISM as well as its detailed structure, focussing on the properties of HI shells and supershells.

Table of Contents

• INTRODUCTION
• BASIC RADIATIVE TRANSFER
• HIGH RESOLUTION IMAGING FACILITIES
• THE STRUCTURE OF THE INTERSTELLAR MEDIUM OF THE GALAXY
• The Composition of the ISM
• The Structure and Phases of the ISM
• Models Describing the ISM
• THE ISM IN NEARBY GALAXIES
• The Magellanic Clouds
• Messier 31
• Messier 33
• IC10 and IC1613
• M101 and NGC 6946
• Edge-on Galaxies
• FORWARD LOOK
• REFERENCES