University of Connecticut

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Astronomy Seminar Series

Wednesday, September 13, 2017
12:00pm – 1:00pm

Storrs Campus
IMS159

Dr. Anna Rosen, Harvard-Smithsonian Center for Astrophysics

An Unstable Truth: How Massive Stars get their Mass

Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. During their formation, the radiation pressure exerted by massive stars on the gas and dust around them can become stronger than their gravitational attraction, thereby inhibiting their growth by accretion. Therefore, detailed simulation of the formation of massive stars requires an accurate treatment of radiation. For this purpose, I will present a new, highly accurate radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. With this new tool, we performed a set of three-dimensional radiation hydrodynamic simulations of the collapse of massive pre-stellar cores with laminar and turbulent initial conditions. We find that mass is channeled to the stellar system via gravitational and Rayleigh-Taylor (RT) instabilities through nonaxisymmetric disks and filaments that self-shield against radiation pressure while allowing for radiation to escape through optically thin regions. Furthermore, we find that turbulence and RT instabilities enhance the development of optically thick filaments that accrete onto massive stars. Our results suggest that RT features are significant and should be present around accreting massive stars throughout their formation.

Dr. Anna Rosen is a Postdoctoral Fellow at the Harvard-Smithsonian Center for Astrophysics. She is a recent PhD from the University of California at Santa Cruz. Dr. Rosen is an expert in developing computational methods for numerical simulations and uses these to study how massive stars are formed. She studies the destructive role that radiation, stellar winds, and cosmic rays have on forming stars.

Contact:

Prof. Whitaker

Physics Department (primary), UConn Master Calendar

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