18 October 2007
18 October 2007
Speaker: Charles Lada (CfA)
Title: Dark Nebular Cores and the Origin of Stellar Masses
Abstract:
Detailed knowledge of the initial distribution of stellar masses at
birth (the IMF) and how this quantity varies through space and time is
necessary to predict the evolution of all stellar systems from star
clusters to galaxies. Yet the origin of stellar masses remains one of
the most fundamental unsolved problems of astrophysics. Stars form in
the dense cores of dark nebulae, but little is understood about the
detailed physical properties of these cores prior to star formation
and even less is understood about their origin. Yet both these issues
are critically linked to understanding the origin of stellar masses
and the IMF. In this colloquium I will first review the current
knowledge concerning functional form and universality of the IMF as
derived from observations of field stars and extremely young clusters.
I will then relate this knowledge to exciting new results concerning
the physical nature of dense cores on the verge of star formation. I
will argue that these results suggest that the distribution of initial
stellar masses derives directly from the distribution of dense core
masses which itself may have its origins in a process of simple
thermal fragmentation in a pressurized medium. The initial
distribution of stellar birth masses produced by star formation may
therefore be the result of the interplay only a few very basic and
measurable physical processes.
Video of the Presentation
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