A Constraint on brown dwarf formation via ejection: radial variation of the stellar and substellar mass function of the young open cluster IC2391

摘要

Using the Wide Field Imager (WFI) at the ESO 2.2m telescope at La Silla andthe CPAPIR camera at the CTIO 1.5m telescope at Cerro Tololo, we have performedan extensive, multiband photometric survey of the open cluster IC2391 (D~146pc,age~50Myr, solar metallicity). Here we present the results from our photometricsurvey and from a spectroscopic follow-up of the central part of the survey.