Daniel APAI : Steward Observatory, University of Arizona / NASA
The first steps toward planetesimal formation in brown dwarf disks: Implications on protoplanetary disks
Dust processing -- grain growth and crystallization -- and dust settling are the first observable steps toward planetesimal formation. With disks identified around young stars of diverse masses down to brown dwarfs and even to planetary mass objects, it is natural to ask whether or not the first steps of planet formation will occur in every disk? Which factors govern the onset of planet formation? I will present Spitzer spectroscopic observations of young brown dwarf disks and show that grain growth, crystallization, and dust settling all occur in these low-mass and cool disks in a way similar to that in disks around low- and intermediate-mass stars. I will discuss the surprising finding of highly crystalline inner disks and its implications to the general picture of dust processing, thermal history and evolution of the protoplanetary disk.Last modified: Sun Jul 9 17:27:39 2006