Invited lecture at Evry Schatzman School 2010: Star Formation in the Local Universe.
astro-ph/1106.1793

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Abstract: This lecture reviews fundamental physical processes on star formation in galaxy interactions and mergers. Interactions and mergers often drive intense starbursts, but the link between interstellar gas physics, large scale interactions, and active star formation is complex and not fully understood yet. We show that two processes can drive starbursts: radial inflows of gas can fuel nuclear starbursts, triggered gas turbulence and fragmentation can drive more extended starbursts in massive star clusters with high fractions of dense gas. Both modes are certainly required to account for the observed properties of starbursting mergers. A particular consequence is that star formation scaling laws are not universal, but vary from quiescent disks to starbursting mergers. High-resolution hydrodynamic simulations are used to illustrate the lectures.

Table of Contents

• INTRODUCTION
• GALAXY-SCALED STAR FORMATION AND ISM DYNAMICS - BASIC FACTS
• Disk stability and star formation
• The heterogeneous and turbulent ISM
• Star formation in the turbulent ISM
• DYNAMICS OF GALAXY INTERACTIONS AND MERGERS
• Dynamical Friction
• Violent Relaxation
• Gas response and tidal torques
• STAR FORMATION TRIGGERING IN INTERACTIONS - FROM MERGERS TO STARBURSTS
• Main observed facts
• Standard theory of merger-induced starbursts: gas inflows and nuclear starbursts
• Limitations of the standard theory
• Star formation in mergers: effect of the turbulent, cloudy ISM
• From triggered turbulence to dense gas excess and starbursts
• Implications for star formation "laws"
• Summary
• STRUCTURE FORMATION IN MERGERS, SUPER STAR CLUSTERS AND GLOBULAR CLUSTERS
• CONCLUSION AND IMPLICATIONS FOR GALAXY FORMATION
• REFERENCES