Dr. D. Hollenbach

University of Nottingham, UK

Galaxy Formation and Evolution over 13 Billion Years

Abstract:

I will discuss new results based on observations and theory which investigate the processes by which galaxies are assembling from the early universe until today. This is one of the central problems in astrophysics and cosmology and relates to a host of other topics including cosmological parameters, the nature of dark matter and dark energy, and how star formation takes places. I will discuss how we can now use observations to measure a host of galaxy properties including their masses, star formation rates, sizes and structure/morphologies over 13 billion years of cosmic time. This includes observational evidence for evolution of these measurable properties, and what this means for the physics behind the formation of galaxies. With this we can now confront detailed theories of the universe and dark matter which have strong predictions for how galaxies assemble. Some of the galaxy formation processes I will discuss include new observations of the merger history of galaxies back to when the universe was only one billion years old, and how with these new results we are now able to determine what role mergers have had in galaxy formation at the earliest times. I will furthermore discuss the implications of these results for other areas of astrophysics, including: cosmological predictions, future gravitational wave detections with LISA, as well as if there is a ‘star formation catastrophe’ at the earliest times in the universe. Finally I will discuss James Webb Space Telescope (JWST) projects I am leading, supported by an Advanced ERC grant, which will answer fundamental questions about the very first generation of galaxies and stars formed at the start of the universe in its first few 100 million years, an epoch we cannot current probe.

Location: 31 Fitzwilliam Place

Upcoming seminars:

https://www.dias.ie/2018/10/23/astronomy-and-astrophysics-seminar-schedule-2019/(opens in a new tab)