Episodic accretion in binary protostars emerging from self-gravitating solar mass cores

TL;DR

This study uses numerical simulations to explore how binary and multiple protostar systems exhibit episodic accretion, influencing their luminosity and mass accumulation, with implications for understanding observed protostellar luminosity variations.

Contribution

It demonstrates that binary systems are more prone to episodic accretion than isolated protostars, providing new insights into protostellar evolution and luminosity variability.

Findings

Binary systems show more episodic accretion than isolated protostars.

Most protostellar mass is accumulated within the first 10^5 years.

Average accretion rate decreases over time, explaining low luminosities.

Abstract

Observations show a large spread in the luminosities of young protostars, which are frequently explained in the context of episodic accretion. We here test this scenario using numerical simulations following the collapse of a solar mass molecular cloud using the GRADSPH code, varying the strength of the initial perturbations and the temperature of the cores. A specific emphasis of this paper is to investigate the role of binaries and multiple systems in the context of episodic accretion, and to compare their evolution to the evolution in isolated fragments. Our models form a variety of low mass protostellar objects including single, binary and triple systems with binaries more active in exhibiting episodic accretion than isolated protostars. We also find a general decreasing trend for the average mass accretion rate over time, suggesting that the majority of the protostellar mass is accreted within the first 10^5 years. This result can potentially help to explain the surprisingly low average luminosities in the majority of the protostellar population.