Volume 434, Number 3, May II 2005
|Page(s)||939 - 948|
|Section||Galactic structure, stellar clusters, and populations|
|Published online||18 April 2005|
A deep, wide-field search for substellar members in NGC 2264
Laboratoire d'Astrophysique, Observatoire de Grenoble, Université Joseph Fourier, 38041 Grenoble Cedex 09, France e-mail: [tkendall;jbouvier]@obs.ujf-grenoble.fr
2 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK e-mail: firstname.lastname@example.org
3 Department of Physics and Astronomy, Vanderbilt University, 1807 Station B, Nashville, TN 37235, USA
Accepted: 16 January 2005
We report the first results of our ongoing campaign to discover the first brown dwarfs (BD) in NGC 2264, a young (3 Myr), populous star forming region for which our optical studies have revealed a very high density of potential candidates – 236 in <1 deg2 – from the substellar limit down to at least ~20 MJup for zero reddening. Candidate BD were first selected using wide field () band imaging with CFH12K, by reference to current theoretical isochrones. Subsequently, 79 (33%) of the sample were found to have near-infrared 2MASS photometry ( mag or better), yielding dereddened magnitudes and allowing further investigation by comparison with the location of NextGen and DUSTY isochrones in colour–colour and colour–magnitude diagrams involving various combinations of I, J, H and Ks. We discuss the status and potential substellarity of a number of relatively unreddened () likely low-mass members in our sample, but in spite of the depth of our observations in , we are as yet unable to unambiguously identify substellar candidates using only 2MASS data. Nevertheless, there are excellent arguments for considering two faint (observed and 21.2) objects as cluster candidates with masses respectively at or rather below the hydrogen burning limit. More current candidates could be proven to be cluster members with masses around 0.1 via gravity-sensitive spectroscopy, and deeper near-infrared imaging will surely reveal a hitherto unknown population of young brown dwarfs in this region, accessible to the next generation of deep near-infrared surveys.
Key words: stars: low-mass, brown dwarfs / infrared: stars / surveys / Galaxy: open clusters and associations: individual: NGC 2264
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.