Driven and Decaying Turbulence Simulations of Low‐Mass Star Formation: From Clumps to Cores to Protostars

2008/06/05 by Stella S. R. Offner, Richard I. Klein, Christopher F. McKee · 3 citations
Chemistry · Physics and Astronomy · #Accretion (finance) #Adaptive mesh refinement #Astro and Planetary Science #Astrophysics and Star Formation Studies #Barotropic fluid #Fullerene Chemistry and Applications #Molecular cloud #Protostar #Star formation #Turbulence #astro-ph

paper · pdf · doi:10.1086/590238

16 pages, 17 figures, accepted to ApJ

arxiv created 2008/06/05 · openalex publication_date 2008/10/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06

Abstract

Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after it is initialized, and one in which it is driven. We use the adaptive mesh refinement (AMR) code, Orion, to perform high-resolution simulations of molecular cloud cores and protostars in environments with both driven and decaying turbulence. We include self-gravity, use a barotropic equation of state, and represent regions exceeding the maximum grid resolution with sink particles. We analyze the properties of bound cores such as size, shape, line width, and rotational energy, and we find reasonable agreement with observation. At high resolution the different rates of core accretion in the two cases have a significant effect on protostellar system development. Clumps forming in a decaying turbulence environment produce high-multiplicity protostellar systems with Toomre Q unstable disks that exhibit characteristics of the competitive accretion model for star formation. In contrast, cores forming in the context of continuously driven turbulence and virial equilibrium form smaller protostellar systems with fewer low-mass members. Our simulations of driven and decaying turbulence show some statistically significant differences, particularly in the production of brown dwarfs and core rotation, but the uncertainties are large enough that we are not able to conclude whether observations favor one or the other.

Citations

• The formation of star clusters - I. Three-dimensional simulations of hydrodynamic turbulence
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• Star Formation in a Crossing Time
• The Formation of Brown Dwarfs as Ejected Stellar Embryos
• The Burst Mode of Protostellar Accretion
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• Accretion and the stellar mass spectrum in small clusters
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• The impact of magnetic fields on single and binary star formation
• Accretion in stellar clusters and the initial mass function
• Theory of Star Formation
• The minimum mass for star formation, and the origin of binary brown dwarfs

Cited by

• Independent Core Rotation in Massive Filaments in Orion
• Concurrent formation of supermassive stars and globular clusters: implications for early self-enrichment
• Stellar mass spectrum within massive collapsing clumps