Invited review to appear in IAU Symposium 270 on "Computational Star Formation". Editors: J. Alves, B.G. Elmegreen, J.M. Girart, and V. Trimble (Cambridge University Press).
astro-ph/1009.1253

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OBSERVATIONAL COMPARISON OF STAR FORMATION IN DIFFERENT GALAXY TYPES

Eva K. Grebel


Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg,
Mönchhofstr. 12-14, D-69120 Heidelberg, Germany
email: grebel@ari.uni-heidelberg.de


Abstract. Galaxies cover a wide range of masses and star formation histories. In this review, I summarize some of the evolutionary key features of common galaxy types. At the high-mass end, very rapid, efficient early star formation is observed, accompanied by strong enrichment and later quiescence, well-described by downsizing scenarios. In the intermediate-mass regime, early-type galaxies may still show activity in low-mass environments or when being rejuvenated by wet mergers. In late-type galaxies, we find continuous, though variable star formation over a Hubble time. In the dwarf regime, a wide range of properties from bursty activity to quiescence is observed. Generally, stochasticity dominates here, and star formation rates and efficiencies tend to be low. Morphological types and their star formation properties correlate with environment.


Keywords: galaxies: formation, galaxies: evolution, galaxies: elliptical and lenticular, galaxies: spiral, galaxies: dwarf, galaxies: stellar content


Table of Contents

INTRODUCTION

VERY EARLY STAR FORMATION
Quasars at redshift geq 6
Galaxies at redshift geq 7?

GLOBAL EVOLUTIONARY TRENDS
Downsizing
Mass-metallicity relations
Environmental trends

MASSIVE EARLY-TYPE GALAXIES
Environment and rejuvenation
E+A galaxies

SPIRALS AND IRREGULARS
Stellar halos of disk galaxies
Bulges of disk galaxies and formation scenarios
Disks and long-term evolutionary trends for disk galaxies
Irregulars
Star formation "demographics"

EARLY-TYPE DWARFS

REFERENCES

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