Issue |
A&A
Volume 411, Number 2, November IV 2003
|
|
---|---|---|
Page(s) | 91 - 97 | |
Section | Galactic structure, stellar clusters, and populations | |
DOI | https://doi.org/10.1051/0004-6361:20034219 | |
Published online | 17 November 2003 |
Research Note
How do binary separations depend on cloud initial conditions?
1
European Southern Observatory, Casilla 19001, Santiago 19, Chile
2
Department of Astronomy, SW319, Indiana University, Bloomington, Indiana 47405, USA
3
Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
Corresponding author: M. Sterzik, msterzik@eso.org
Received:
20
August
2003
Accepted:
28
August
2003
We explore the consequences of a star formation scenario in which
the isothermal collapse of a rotating, star-forming core is followed by prompt
fragmentation into a cluster containing a small number () of
protostars and/or substellar objects. The subsequent evolution of the cluster
is assumed to be dominated by dynamical interactions among cluster members,
and this establishes the final properties of the binary and multiple systems.
The characteristic scale of the fragmenting core is determined by the cloud
initial conditions (such as temperature, angular momentum and mass), and we
are able to relate the separation distributions of the final binary population
to the properties of the star-forming core. Because the fragmentation scale
immediately after the isothermal collapse is typically a factor of 3-10 too large, we
conjecture that fragmentation into small clusters followed by dynamical
evolution is required to account for the observed binary separation
distributions. Differences in the environmental properties of the cores are
expected to imprint differences on the characteristic dimensions of the binary
systems they form. Recent observations of hierarchical systems, differences in
binary characteristics among star forming regions and systematic variations
in binary properties with primary mass can be interpreted in the context of
this scenario.
Key words: stars: binaries: general / stars: binaries: close / stars: binaries: visual / stars: formation / stars: low-mass, brown dwarfs
© ESO, 2003
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.