Formation and evolution of protostellar accretion discs - II. From 3D simulation to a simple semi-analytic model of Class 0/I discs

Wenrui Xu, Matthew W. Kunz

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

We use a 3D radiative non-ideal magnetohydrodynamic simulation to investigate the formation and evolution of a young protostellar disc from a magnetized pre-stellar core. The simulation covers the first ∼10 kyr after protostar formation and shows a massive, weakly magnetized disc with radius that initially grows and then saturates at ∼30 au. The disc is gravitationally unstable with prominent large-amplitude spiral arms. We use our simulation results and a series of physical arguments to construct a predictive and quantitative physical picture of Class 0/I protostellar disc evolution from several aspects, including (i) the angular-momentum redistribution in the disc, self-regulated by gravitational instability to make most of the disc marginally unstable; (ii) the thermal profile of the disc, well-approximated by a balance between radiative cooling and accretion heating; and (iii) the magnetic-field strength and magnetic-braking rate inside the disc, regulated by non-ideal magnetic diffusion. Using these physical insights, we build a simple 1D semi-analytic model of disc evolution. We show that this 1D model, when coupled to a computationally inexpensive simulation for the evolution of the surrounding pseudo-disc, can be used reliably to predict disc evolution in the Class 0/I phase. The predicted long-term evolution of disc size, which saturates at ∼30 au and eventually shrinks, is consistent with a recent observational survey of Class 0/I discs. Such hierarchical modelling of disc evolution circumvents the computational difficulty of tracing disc evolution through Class 0/I phase with direct, numerically converged simulations.

Original languageEnglish (US)
Pages (from-to)2142-2168
Number of pages27
JournalMonthly Notices of the Royal Astronomical Society
Volume508
Issue number2
DOIs
StatePublished - Dec 1 2021

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • ISM: clouds
  • MHD
  • accretion, accretion disc1
  • magnetic fields
  • stars: formation

Fingerprint

Dive into the research topics of 'Formation and evolution of protostellar accretion discs - II. From 3D simulation to a simple semi-analytic model of Class 0/I discs'. Together they form a unique fingerprint.

Cite this