College of Science

SEMINAR: Jorge Moreno [University of Victoria & Canadian Institute for Theoretical Astrophysics]

Love & Deception: A Tale of Two Merging Galaxies

Jan 28, 2014 10:50 AM to Jan 28, 2014 12:00 PM at Building 8, Room 241

Jorge MorenoMergers of galaxies are amongst the most spectacular events in the night sky. But more importantly, mergers play a crucial role in the formation and evolution of galaxies. For instance, mergers can do the following: (1) they can change the shape of a galaxy, from a disk-like system with spiral arms into a massive ellipsoid; (2) they can funnel copious amounts of gas into the central regions, which then produces huge episodes of star formation; and (3) some of this gas can feed a supermassive black hole at the centre, turning it into an ultra-luminous quasar. From the theoretical front, numerical simulations of two interacting galaxies are finally beginning to unveil some of the physical mechanisms behind these phenomena. In particular, supercomputer models today predict how and when our Milky Way galaxy will merge with Andromeda, our nearest neighbor -- which will result in “Milkomeda”, a massive elliptical galaxy!

On the first part of this seminar I will briefly review the latest advances in the field of galaxy mergers and interactions, both from an observational and a computational point of view. In the second part of the talk, I will describe my latest investigations, which put a fundamental belief held dear by many researchers into question. Namely, can we really assume that two merging galaxies evolve in complete isolation from the rest of the universe, as is commonly adopted in computer simulations? For the remainder of the talk, I will describe how my research program attempts to answer this question, which requires bridging the gap between what is happening at the scales of individual galaxies and scales that cover the whole observable universe.

I conclude with an overview of the future. In particular, the next two decades will witness two paramount revolutions in the field of extragalactic astronomy. First, satellites like the James Webb Space Telescope (the descendant of the Hubble Space Telescope) will observe galaxies at unprecedented distances -- and will collect light emitted billions of years ago, when the universe was at its infancy. Secondly, a new generation of integral-field surveys will observe large numbers of galaxies, each with exquisite detail -- providing us with a unique opportunity to connect the neighborhood surrounding a galaxy to its internal structural evolution. These demanding investigations will require the best universe-scale simulations (for example, the Illustris Simulation) -- and the latest state-of-the-art statistical “Big Data” tools, currently in vogue in other fields and industries. Several interesting research projects will be generated, to be tackled by motivated CSU Pomona students with inquisitive and curious minds!

10:50 a.m. Refreshments
11:00 a.m. Seminar