Mini Mergers with Major Consequences for Star Forming Galaxies

Abstract

An overwhelming body of research shows that the gravitational torques experienced in galaxy-galaxy collisions cause galaxies to form stars at an expedited rate and drive changes to galaxy structures. Much of this research has focused on collisions between galaxies of comparable masses (major/minor mergers) due to observational challenges in detecting small, low-mass galaxies on collision courses with larger galaxies. In this work, the speaker focuses on "mini" collisions using a large, high-resolution simulation of galaxy formation. He shows that mini mergers have an inconspicuously important role in driving structural change and star formation in galaxies due to a unique X-factor: the average timescale on which mini collisions cause star-formation efficiency and asymmetry to be elevated is longer than the average time between mini collision events. This major role of mini colliders raises curious questions as to whether they drive these changes gravitationally, carrying gas into galaxies, or whether they are simply along-for-the-ride with large scale gas inflows.

About the Speaker

Dr. Connor BOTTRELL’s research focuses on how galaxies assemble, their structures, and how their structures can be used to understand dark matter. He completed his PhD in Astronomy at the University of Victoria, Canada which is his home-city. After that, he spent 3 years as a Kavli Fellow at the Kavli Institute for the Physics and Mathematics of the Universe in Tokyo, Japan. Since mid-2023, he has been a Forrest Research Foundation Fellow at the International Centre for Radio Astronomy Research at the University of Western Australia.

About the Program

For more information, please refer to the program website at http://iasprogram.ust.hk/particle_theory.

For Attendees' Attention

Seating is on a first come, first served basis.