The Low Mass End of the IMF Unveiled by the WIRCam/CFHT Survey of Nearby Young Clusters

Abstract

The observational characterization of the stellar mass function in galactic clusters, the field, and even other galaxies, has resulted in a wealth of parameters that must be reproduced and explained by any successful star formation theory. To extend our knowledge on the mass function to the substellar regime, we have conducted a large observational survey of nearby young clusters (ρ Oph, IC 348, Serpens, and λ Ori). We adopted a twofold approach to this study, using both near-IR photometry to find all candidate substellar members and extensive spectroscopic follow-up to derive a spectroscopic IMF, and deep methane imaging to search for the lowest mass members. I will present the results of this longterm endeavor, where we have found no evidence for variations in the substellar mass function across different clusters, and have uncovered a handful of candidate young T dwarfs likely to represent the minimum mass for star formation.