A deep optical survey of IC 2391 .

Le résumé fourni par la source

We report the outcome of a deep optical photometric survey of a 30×30 square arcmin area in the IC 2391 young open cluster, complemented by IR photometry from the 2MASS catalogue and the Spitzer space telescope. The optical data were obtained by using the Wide-Field Imager (WFI) at the ESO 2.2m telescope; the photometric completeness limit of this survey at 3σ level (V=24.7, RC=23.7 and IC=23.0) is ∼2 magnitudes fainter than previous optical surveys of this cluster and is sufficient for the detection of low-mass members down to the brown dwarf (BD) boundary of ∼0.03 M . We aim at uncovering new low-mass members and BDs in order to constrain the shape of the Initial Mass Function (IMF) of IC 2391 in the low-mass domain, which is currently under debate. In addition, the age (∼50 Myr) and distance (∼150 pc) of IC 2391 offer a unique combination to study the evolution of debris-disks around low-mass stars, which is a crucial step toward our understanding of the terrestrial planet formation mechanism. By merging our optical data with IR photometry from 2MASS and Spitzer, we search for IR excess emission in the cluster members, which is indicative of debris-disks, and aim at investigating the disk properties.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.