Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:0803.0561)
· On-line Data
· References in the article
· Citations to the Article (10) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (139)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
A Multiplicity Census of Young Stars in Chamaeleon I
Authors:
Lafrenière, David; Jayawardhana, Ray; Brandeker, Alexis; Ahmic, Mirza; van Kerkwijk, Marten H.
Affiliation:
AA(Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada.), AB(Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada.), AC(Stockholm Observatory, AlbaNova University Center, SE-105 91 Stockholm, Sweden.), AD(Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada.), AE(Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada.)
Publication:
The Astrophysical Journal, Volume 683, Issue 2, pp. 844-861. (ApJ Homepage)
Publication Date:
08/2008
Origin:
UCP
ApJ Keywords:
Stars: Binaries: General, Stars: Formation, Stars: Low-Mass, Brown Dwarfs
DOI:
10.1086/590239
Bibliographic Code:
2008ApJ...683..844L

Abstract

We present the results of a multiplicity survey of 126 stars spanning ~0.1-3 Msolar in the ~2 Myr old Chamaeleon I star-forming region, based on adaptive optics imaging with the ESO Very Large Telescope. Our observations have revealed 30 binaries and six triples, of which 19 and four, respectively, are new discoveries. The overall multiplicity fraction we find for Cha I (~30%) is similar to those reported for other dispersed young associations, but significantly higher than seen in denser clusters and the field, for comparable samples. Both the frequency and the maximum separation of Cha I binaries decline with decreasing mass, while the mass ratios approach unity; conversely, tighter pairs are more likely to be equal mass. We confirm that brown dwarf companions to stars are rare, even at young ages at wide separations. Based on follow-up spectroscopy of two low-mass substellar companion candidates, we conclude that both are likely background stars. The overall multiplicity fraction in Cha I is in rough agreement with numerical simulations of cloud collapse and fragmentation, but its observed mass dependence is less steep than predicted. The paucity of higher order multiples, in particular, provides a stringent constraint on the simulations, and seems to indicate a low level of turbulence in the prestellar cores in Cha I.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints