The large-scale disk fraction of brown dwarfs in the Taurus cloud as measured with Spitzer
Abstract
Aims. The brown dwarf (BD) formation process has not yet been completely understood. To shed more light on the differences and similarities between star and BD formation processes, we study and compare the disk fraction among both kinds of objects over a large angular region in the Taurus cloud. In addition, we examine the spatial distribution of stars and BD relative to the underlying molecular gas. Methods. In this paper, we present new and updated photometry data from the Infrared Array Camera (IRAC) aboard the Spitzer Space Telescope on 43 BDs in the Taurus cloud, and recalculate of the BD disk fraction in this region. We also useed recently available CO mm data to study the spatial distribution of stars and BDs relative to the cloud's molecular gas. Results. We find that the disk fraction among BDs in the Taurus cloud is 41 ± 12%, a value statistically consistent with the one among TTS (58 ± 9%). We find that BDs in transition from a state where they have a disk to a diskless state are rare, and we study one isolated example of a transitional disk with an inner radius of ≈0.1 AU (CFHT BD Tau 12, found via its relatively small mid-IR excess compared to most members of Taurus that have disks. We find that BDs are statistically found in regions of similar molecular gas surface density to those associated with stars. Furthermore, we find that the gas column density distribution is almost identical for stellar and substellar objects with and without disks.
Additional Information
© 2010 EDP Sciences. Received: 16 April 2009; Accepted: 25 January 2010. We thank an anonymous referee for a very detailed and precise report that helped uncover several errors in the first version of this paper. This research has made use of the CDS database. We thank the Programme National de Physique Stellaire (PNPS, CNRS/INSU, France) for financial support. The authors also wish to extend special thanks to those of Hawaiian ancestry on whose sacred mountain of Mauna Kea we are privileged to be guests. Without their generous hospitality, the CFH Telescope observations presented therein would not have been possible.Attached Files
Published - Monin2010p11061Astron_Astrophys.pdf
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Additional details
- Eprint ID
- 19493
- Resolver ID
- CaltechAUTHORS:20100818-103802947
- Programme National de Physique Stellaire (PNPS)
- Centre National de la Recherche Scientifique (CNRS)
- Institut national des sciences de l'Univers (INSU)
- Created
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2010-08-20Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)