Star formation in galaxy interactions and mergers

TL;DR

This paper reviews the complex physical processes driving star formation in galaxy interactions and mergers, highlighting how different mechanisms lead to diverse starburst phenomena and challenging universal star formation laws.

Contribution

It provides a comprehensive overview of the physical mechanisms and simulation insights into star formation during galaxy interactions and mergers.

Findings

Radial gas inflows fuel nuclear starbursts

Gas turbulence and fragmentation drive extended starbursts

Star formation laws vary between quiescent and merging galaxies

Abstract

This lecture reviews the fundamental physical processes involved in 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. 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.