Dr. Steve Boudreault: The Formation Process of Brown Dwarfs as revealed by the Mass Function of IC 2391

Dr. Steve Boudreault, Max Planck Institut fuer Astronomie, Heidelberg 

The Formation Process of Brown Dwarfs as revealed by the Mass Function of IC 2391  

It is still a matter of debate whether stars and sub-stellar objects -- brown
dwarfs -- share the same formation processes or are born differently. Since one
of the scenarios for brown dwarf formation, the embryo ejection mechanism,
predicts high velocity dispersion for the brown dwarfs, their radial
distribution in clusters should be flatter than that of stars. Steve Boudreault
uses deep photometric data of the nearby (~140pc) medium-age (50 Myr) open
cluster IC 2391 to investigate this question by studying the radial variation of
the mass function in the range 0.03 to 0.5 solar masses. Although he finds
evidence for dynamical evolution at higher masses (> 0.15 M_sun), at the low
mass end there is no evidence for a different distribution of stellar and
sub-stellar objects, respectively.