On the distribution of protostar masses

TL;DR

This paper models the distribution of protostar masses considering core-environment systems with stochastic infall durations, showing that the resulting mass distribution resembles the initial mass function and depends on environmental density.

Contribution

It introduces a model linking infall duration distributions to protostar mass distributions, highlighting the role of environment density and structure in star formation.

Findings

Mass distribution resembles the initial mass function under certain conditions.

High environment density increases the high-mass tail of the protostar mass function.

Low-density regions predominantly form low-mass protostars.

Abstract

The distribution of protostar masses is studied for core-environment systems whose duration of infall follows a waiting-time distribution. Each core-environment system has a continuous density profile with no barrier to mass flow. The core is an isothermal sphere and the environment is a filament, a layer, or a uniform medium. The infall is terminated by gas dispersal due to outflows and turbulence. The distribution of infall durations is a declining exponential, the simplest waiting-time distribution. The resulting distribution of protostar masses closely resembles the initial mass function, provided the environment density is sufficiently high, and the distribution of initial core masses is sufficiently narrow. The high-mass tail of the mass function increases strongly with environment density and weakly with environment dimension. Isolated regions of low environment density form protostars of low mass from within the parent core. In contrast, clustered regions of high environment density form protostars of low mass from core gas, and protostars of high mass from core and environment gas.