SONYC: Substellar Objects in Nearby Young Clusters
Koraljka Muzik
University of Toronto

The origins and characteristics of the lowest mass free-floating objects constitute a major question in the study of star formation. SONYC, short for "Substellar Objects in Nearby Young Clusters", is an ongoing project to provide a census of the substellar population in nearby star forming regions. The survey uses extremely deep wide-field optical and near-infrared imaging at 4- to 8-m telescopes, combined with Spitzer photometry. In our extensive follow-up campaigns, we have obtained more than 500 spectra in NGC1333, rho Ophiuchi, and Chamaeleon-I, using MOIRCS and FMOS at the Subaru Telescope, VIMOS and SINFONI at the VLT, and GNIRS at Gemini-N. We report discoveries of ~30 spectroscopically confirmed very-low-mass objects, including one with the mass of about 6 MJup, placing it among the lowest mass free-floating objects identified thus far. Our findings have doubled the number of confirmed brown dwarfs in NGC 1333, and comprise about one fifth of the entire substellar population in rho-Oph. In this talk I will present the results and the status of SONYC. I will investigate the benefits and biases of the currently used observing strategies, address the completeness of the current brown dwarf census in young clusters, and the implications of our findings for star formation theory.

Date: Jeudi, le 2 février 2012
Heure: 11:30
Lieu: Université de Montréal
  Pavillon Roger-Gaudry, local D-460
Contact: David Lafrenière