The turbulent ISM and the stellar IMF

Abstract

In this contribution, we focus on the role that turbulence can play in setting the initial mass function (IMF) of stars. Two theories are contrasted. In the first, the so-called 'turbulent' fragmentation theory, the turbulence is directly responsible for breaking up the cloud into 'cores' which go on to form either a single star or a small N system. In such a picture, the IMF is primordial, since the mass reservoir form the young protostellar system is assumed to be set by the mass of the natal core. In the alternative picture, 'competitive accretion', the final mass of a protostar is determined by its position in the potential well of the cluster. As such the IMF is determined through gravitational dynamics rather than turbulence. We discuss the observation motivation for each of these cases.

Simulating radiative feedback and star cluster formation in GMCs – I. Dependence on gravitational boundedness

“…This ratio may vary from 0.5 up to 10 with the mean being approximately 1 (Solomon et al 1987;Rosolowsky 2007;Hernandez & Tan 2015). Simulations have shown that dense, self-gravitating clumps can still fragment out of clouds that are globally unbound (Clark et al 2005;Clark & Klessen 2008;Bonnell et al 2011). Furthermore, the star formation efficiency is naturally lowered in unbound clouds (Padoan et al 2012).…”