An explanation for the unusual IMF in Taurus

Free access article

Issue		A&A Volume 419, Number 2, May IV 2004


Page(s)		543 - 547
Section		Galactic structure, stellar clusters and populations
DOI		http://dx.doi.org/10.1051/0004-6361:20035802

A&A 419, 543-547 (2004)
DOI: 10.1051/0004-6361:20035802

An explanation for the unusual IMF in Taurus

S. P. Goodwin, A. P. Whitworth and D. Ward-Thompson

Department of Physics & Astronomy, Cardiff University, PO Box 913, 5 The Parade, Cardiff CF24 3YB, UK
(Received 4 December 2003 / Accepted 20 February 2004)

Abstract
In comparison with other well studied star formation regions, Taurus is unusual in several respects. (i) Its stellar initial mass function (IMF) peaks at relatively high mass ( $\sim$ $0.8~ M_\odot$ ), but contains very few stars much more massive than $1 ~M_\odot$ , and is relatively deficient in brown dwarfs. (ii) It has a higher binary fraction, particularly at large separations. (iii) Its core mass function is strongly peaked at a few $M_\odot$ , and the cores have extended envelopes and relatively low levels of turbulence. We present here the results of an ensemble of hydrodynamic simulations which suggest that the unusual stellar IMF in Taurus is a direct consequence of the unusual properties of the cores there. By following the collapse and fragmentation of cores having properties typical of Taurus, we find that roughly 50% of the objects formed in a core, predominantly the low-mass ones, are ejected from the core to form a population of low-mass stars and brown dwarfs with a flat mass function. The remaining objects form multiple systems within the core, accreting until their masses approach $1 ~M_\odot$ ; this produces a population of intermediate-mass stars whose mass function peaks at $\sim$ $0.8~ M_\odot$ . Together these two populations reproduce the IMF in Taurus very well. This demonstrates, for the first time, a direct causal link between the core mass function and the stellar IMF in a star formation region.

Key words: stars: formation -- ISM: clouds -- ISM: structure -- methods: numerical

Offprint request: S. P. Goodwin, Simon.Goodwin@astro.cf.ac.uk

SIMBAD Objects

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.