Radiative Feedback in Massive Star and Cluster Formation

TL;DR

This study uses advanced simulations to explore how radiative feedback influences massive star formation, revealing that ionization does not halt accretion but fragmentation-induced starvation does, aligning with observed star cluster properties.

Contribution

The paper introduces a novel adaptive-mesh ray-tracing simulation method to analyze the complex interplay of radiation, gravity, and magnetic fields in massive star formation.

Findings

Ionization feedback does not prevent protostellar growth.

Fragmentation-induced starvation limits accretion.

Magnetic fields reduce star formation rate and promote massive star formation.

Abstract

Understanding the origin of high-mass stars is central to modern astrophysics. We shed light on this problem with simulations using a novel, adaptive-mesh, ray-tracing algorithm. These simulations consistently follow the gravitational collapse of a massive molecular cloud core, the subsequent build-up and fragmentation of the accretion disk surrounding the nascent star, and, for the first time, the interaction between its intense UV radiation field and the infalling material. We show that ionization feedback can neither stop protostellar mass growth nor suppress fragmentation. We discuss the effects of feedback by ionizing and non-ionizing radiation on the evolution of the stellar cluster. The accretion is not limited by radiative feedback but by the formation of low-mass companions in a process we call "fragmentation-induced starvation". This behavior consistently reproduces the observed relation between the most massive star and the total mass of stars in a cluster. We show that magnetic fields reduce the star formation rate and lead to the formation of more massive stars.