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Formation of Binary / Multiple Star Systems

Speaker:Dr. Jeremy J. L. Lim
Affiliation:Department of Physics, The University of Hong Kong
Date:November 20, 2009 (Fri)
Time:5:00-6:30 p.m.
Venue:Lecture Theatre T3, G/F, Meng Wah Complex, HKU


Most stars with masses comparable to our own Sun are born as members of binary or multiple systems. Yet, although we have an observationally-supported theoretical framework for how single Sun-like stars (and their accompanying planets) form, we lack a commonly accepted framework for how Sun-like stars in binary or multiple systems form. In this presentation, I briefly describe the two most commonly invoked theoretical models for how binary/multiple protostellar systems form - fragmentation versus capture. These models make very different predictions for the properties of the resultant protostellar system that can be tested observationally. I compare the model predictions with observations of the multiple protostellar system L1551 IRS5, one of the best studied and closest protostellar system. I show that this system have properties consistent with their formation via fragmentation, providing the most direct evidence yet for the formation of any binary/multiple protostellar systems through fragmentation. I conclude with a brief summary of ongoing work, and plans for future work.


About the Speaker:

Jeremy Lim is an Associate Professor Physics, HKU. His research interests includes topics Astrophysics - Star Formation, Stellar Activities, Evolved Stars, External Galaxies, and Radio Interferometry.


Physics colloquium series is organized to introduce cutting edge researches and new development in physics, designed to be suitable to graduate and undergraduate students, and also to scientists working on different fields. Each colloquium will generally start with an extensive introduction of the background of the field, followed by forefront research topics and results. The colloquium will serve as an education forum for students and laymen alike, and also serve as a platform for exchange and update their knowledge of various branches of physics among academic staff members.