Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/institute/smo/events/colloquia/2008/ColloquiaApril9Lada.pdf Дата изменения: Unknown Дата индексирования: Wed Feb 6 01:50:10 2013 Кодировка: Поисковые слова: clouds

Refreshments at 3:15 PM, Talks at 3:30 PM in the John N . Bahcall Audit orium www.stsci.edu/inst itute/sd/talks/C olloquia for updates

Wednesday April 9, 2008
Charles Lada, Harvard-Smithsonian Center for Astrophysics

Dark Nebular Cores and the Origin of Stellar Masses
Detailed k nowledge of the initial distribution of stellar mass es at birth (the I MF) and how this quantity varies through space and time is necess ary 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 astrophysic s. Stars form in the dense cores of dark nebulae, but little is understood about the detailed phys ical properties of these cores prior to star formation and even less is understood about their origin. Yet both these iss ues are critically link ed to understanding the origin of stellar masses and the I MF. In this colloquium I will relate current knowledge concerning the functional form and univ ers ality of the IMF to exciting new results concerning the physical nature of dense cores on t he verge of star formation. I will argue that thes e results suggest that the distribution of initial stellar mas ses derives directly from the distribution of dens e core masses which itself may have its origins in a proc ess 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 of only a few very bas ic and measurable physic al process es.