University of Connecticut

Events Calendar

Astronomy Seminar Series

Wednesday, September 20, 2017
12:00pm – 1:00pm

Storrs Campus

Dr. Sandro Tacchella, Harvard-Smithsonian Center for Astrophysics

The Formation and Evolution of Bulges and Disks in High-Redshift Galaxies

I will start by presenting a simple model that links dark matter halos to galaxies for gaining a better understanding of the evolution of the cosmic star-formation rate density, describing why redshift z~2 marks a key epoch for the formation of galaxies. I will then use state-of-the-art cosmological hydrodynamical zoom-in simulations to explore the physical processes that are responsible for the formation and evolution of bulges in galaxies at these early cosmic times. I will present evidence from the simulations that gas-driven compaction is a key phase in the life of galaxies while they evolve along the so-called star-forming Main Sequence. The main part of my talk will then present observations of z~2 star-forming galaxies combining rest-frame Far-UV-to-optical HST imaging and VLT SINFONI Adaptive-Optics spectra of the H-alpha line emission. In addition to comparing these observations with the simulations, I demonstrate not only that these massive galaxies at the peak of cosmic star-formation activity have already achieved the stellar density distributions that we see in massive spheroids at z=0, but also that they have outward-increasing specific SFR radial profiles, i.e., suppressed star-formation activity in their central bulge regions.

Dr. Sandro Tacchella is a CfA Postdoctoral Fellow at the Harvard-Smithsonian Center for Astrophysics. He is a recent PhD from the Extragalactic Astrophysics Research Group of ETH Zurich. Dr. Tacchella studies the formation and evolution of galaxies across cosmic time using both observational data from the Hubble Space Telescope and Very Large Telescope, as well as cosmological zoom-in simulations.


Prof. Whitaker

Physics Department (primary), UConn Master Calendar

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