Publications of the Astronomical Society of the Pacific
109: 937-950, 1997 September


Star Formation in Irregular Galaxies: A Review of
Several Key Questions

Deidre A. Hunter

Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, Arizona 86001
Electronic mail: dah@lowell.edu

KEY WORDS: galaxies: irregular, star formation


ABSTRACT. Star formation takes place in a different and simpler environment in irregular galaxies compared to spirals. Because they lack spiral density waves, non-interacting irregular galaxies are interesting laboratories for all of the internal processes other than spiral density waves that are involved in normal star formation. Most irregular galaxies are currently forming stars, and some are forming stars at rates that are comparable to those for spiral galaxies. In addition, there is a larger range in star formation rates among irregular galaxies than spirals. I discuss the status of our knowledge about large-scale star formation processes in irregular galaxies in the context of four key questions: What regulates star formation on global and local scales in irregular galaxies? What feedback processes are operating? What are the consequences of differences in the interstellar medium on the star formation process? What role does the extended gas play in the evolution of irregular galaxies? Answers to these questions are important for understanding not only how star formation works in irregular galaxies, but in understanding the process by which galaxies form stars and evolve anywhere.


Table of Contents

INTRODUCTION

WHAT REGULATES STAR FORMATION ON GLOBAL AND LOCAL SCALES IN IRREGULAR GALAXIES?

WHAT FEEDBACK PROCESSES ARE OPERATING IN IRREGULARS?

WHAT ARE THE CONSEQUENCES OF DIFFERENCES IN THE ISM ON THE STAR FORMATION PROCESS?

WHAT ROLE DOES THE EXTENDED GAS PLAY IN IRREGULARS?

SUMMARY

REFERENCES

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