O.M. Stewart Colloquium Series

Thursday, January 26, 2017 4:00pm

Room 223A, Physics Building Library


Dr. Yicheng Guo, University of California – Santa Cruz presents, "What Giant Star-forming Clumps Tell Us About the Assembly Histories of Galaxies." Studies of galaxy formation and evolution have made remarkable progress in the past two decades. Thanks to modern telescopes, such as HST, Keck, Spitzer, and SDSS, the integrated properties of distant galaxies -- mass, size, color, and shape -- have been accurately measured and used to display a broad picture of galaxy assembly across cosmic time. With the powers of current telescopes and super computers, extragalactic astronomy has come to a critical point to study the internal structures of distant galaxies.

Dr. Yicheng Guo

In this talk, Dr. Guo will present his work of studying a common and important internal feature of distant star-forming galaxies, namely giant star-forming clumps, and show how the internal structure significantly improves our understanding of the accretion history of galaxies, evolution of disks, and formation of bulges. He uses the data from CANDELS, the largest HST survey program, and state-of-the-art cosmological hydrodynamic simulations to answer three questions: (1) When and how were clumps formed? (2) How did they evolve once being formed? (3) What do clumps tell us about the physical mechanisms that regulate star formation? The three aspects reveal clues of how galaxies evolve from small, irregular blobs in early universe into today's Hubble Sequence. Dr. Guo also will discuss how future multi-wavelength facilities, e.g., JWST, WFIRST, and SKA, would provide new, key information to understand galaxies' internal structures.

The event will be hosted by Prof. Linda Godwin of the Department of Physics and Astronomy. Refreshments will be served at 3:30 p.m., followed by Dr. Guo's talk at 4 p.m.