Starburst triggered by compressive tides in galaxy mergers

TL;DR

This paper demonstrates that compressive tidal forces during galaxy mergers can promote star cluster formation, with simulations showing good agreement with observed cluster distributions and formation timescales.

Contribution

It reveals the role of compressive tides in galaxy mergers as a mechanism for star cluster formation, supported by N-body simulation results.

Findings

Compressive tidal regions align with observed young star clusters.

Characteristic timescales of 10-30 Myrs match cluster formation periods.

Simulation results agree with observed spatial distribution of clusters.

Abstract

The tidal field of galaxies is known generally to be disruptive. However, in the case of galaxy mergers, a compressive mode of tidal wave may develop and last long enough to cocoon the formation of star clusters. Using an N-body simulation of the Antennae galaxies, we derive the positions of these compressive regions and the statistics of their duration. Excellent agreement between the spatial distribution of tides and observed young clusters is found, while the characteristic e-folding times of 10 to 30 Myrs derived for the tidal field compare well with cluster formation time-scales.