Collapse of a molecular cloud core to stellar densities: the radiative impact of stellar core formation on the circumstellar disc

TL;DR

This study uses advanced 3D radiation hydrodynamics to explore how stellar core formation impacts circumstellar discs, revealing energetic outbursts that influence star formation, jet launching, and possibly explaining meteorite features.

Contribution

First 3D radiation hydrodynamical simulations of molecular cloud core collapse beyond stellar core formation, highlighting energetic feedback effects on circumstellar discs.

Findings

Stellar core formation releases energy comparable to disc binding energy.

Formation of a bipolar outflow traveling over 50 AU.

Potential cyclic outbursts influencing star luminosity and meteorite composition.

Abstract

We present results from the first three-dimensional radiation hydrodynamical calculations to follow the collapse of a molecular cloud core beyond the formation of the stellar core. We find the energy released by the formation of the stellar core, within the optically-thick first hydrostatic core, is comparable to the binding energy of the disc-like first core. This heats the inner regions of the disc, drives a shock wave through the disc, dramatically decreases the accretion rate on to the stellar core, and launches a temporary bipolar outflow perpendicular to the rotation axis that travels in excess of 50 AU into the infalling envelope. This outburst may assist the young protostar in launching a conventional magnetic jet. Furthermore, if these events are cyclic, they may provide a mechanism for intense bursts of accretion separated by long periods of relatively quiescent accretion which can potentially solve both the protostellar luminosity problem and the apparent age spread of stars in young clusters. Such outbursts may also provide a formation mechanism for the chondrules found in meteorites, with the outflow transporting them to large distances in the circumstellar disc.