Angular Momenta, Magnetization, and Accretion of Protostellar Cores

Abstract

Building on our previous hydrodynamic study of the angular momenta of cloud cores formed during gravitational collapse of star-forming molecular gas in our previous work, we now examine core properties assuming ideal magnetohydrodynamics (MHD). Using the same sink-patch implementation for the \emph{Athena} MHD code, we characterize the statistical properties of cores, including the mass accretion rates, specific angular momenta, and alignments between the magnetic field and the spin axis of the core on the $0.1\mathrm{pc}$ scale. Our simulations, which reproduce the observed relation between magnetic field strength and gas density, show that magnetic fields can help collimate low density flows and help seed the locations of filamentary structures. Consistent with our previous purely hydrodynamic simulations, stars (sinks) form within the heterogeneous environments of filaments, such that accretion onto cores is highly episodic leading to short-term variability but no long-term monotonic growth of the specific angular momenta. With statistical characterization of protostellar cores properties and behaviors, we aim to provide a starting point for building more realistic and self-consistent disk formation models, helping to address whether magnetic fields can prevent the development of (large) circumstellar disks in the ideal MHD limit.

arXiv comment13 pages, 9 figures, accepted by ApJ

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Cited by in corpus (13)

• Anisotropic Infall and Substructure formation in Embedded Disks
• Origin of hydrogen isotopic variations in chondritic water and organics
• Reflections on nebulae around young stars: A systematic search for late-stage infall of material onto Class II disks
• The JCMT BISTRO survey: alignment between outflows and magnetic fields in dense cores/clumps
• The Interplay between Ambipolar Diffusion and Hall Effect on Magnetic Field Decoupling and Protostellar Disc Formation
• Testing a New Model of Embedded Protostellar Disks Against Observation: The Majority of Orion Class 0/I Disks Are Likely Warm, Massive, and Gravitationally Unstable
• Stellar Spins in the Open Cluster NGC 2516
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• A Study of Stellar Spins in 15 Open Clusters
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• Magnetic field alignment with dense cores in the transition between cloud and core scales
• Grouped star formation: converting sink particles to stars in hydrodynamical simulations