Geometry, Kinematics, and Magnetization of Simulated Prestellar Cores

Abstract

We utilize the more than 100 gravitationally-bound dense cores formed in our three-dimensional, turbulent MHD simulations reported in Chen & Ostriker (2015) to analyze structural, kinematic, and magnetic properties of prestellar cores. Our statistical results disagree with the classical theory of star formation, in which cores evolve to be oblate with magnetic field parallel to the minor axes. Instead, we find that cores are generally triaxial, although the core-scale magnetic field is still preferentially most parallel to the core's minor axis and most perpendicular to the major axis. The internal and external magnetic field directions are correlated, but the direction of integrated core angular momentum is misaligned with the core's magnetic field, consistent with recent observations. The ratio of rotational/total kinetic and rotational/gravitational energies are independent of core size and consistent in magnitude with observations. The specific angular momentum also follows the observed relationship $L/M\propto R^{3/2}$, indicating rotation is acquired from ambient turbulence. With typical $E_{\mathrm{rot}}/E_K\sim 0.1$, rotation is not the dominant motion when cores collapse.

15 pages, 13 figures, accepted for publication in ApJ

References in corpus (14)

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• Athena: A New Code for Astrophysical MHD
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• Unveiling the Role of the Magnetic Field at the Smallest Scales of Star Formation
• Impact of Protostellar Outflows on Turbulence and Star Formation Efficiency in Magnetized Dense Cores
• Disk Formation Enabled by Enhanced Resistivity
• Change of Magnetic Field$-$Gas Alignment at Gravity-Driven Alfvénic Transition in Molecular Clouds: Implications for Dust Polarization Observations
• OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars
• Core and filament formation in magnetized, self-gravitating isothermal layers
• Prestellar Core Formation, Evolution, and Accretion from Gravitational Fragmentation in Turbulent Converging Flows
• Synthetic Observations of Magnetic Fields in Protostellar Cores
• Fantastic Striations and Where to Find Them: Origin of Magnetically Aligned Striations in Interstellar Clouds

Cited by in corpus (21)

• Interferometric observations of magnetic fields in forming stars
• Zooming in on Individual Star Formation: Low- and High-mass Stars
• Disk Formation in Magnetized Dense Cores with Turbulence and Ambipolar Diffusion
• Turbulence, Coherence and Collapse: Three Phases for Core Evolution
• The JCMT BISTRO survey: alignment between outflows and magnetic fields in dense cores/clumps
• The Origins of Protostellar Core Angular Momenta
• Dust clearing by radial drift in evolving protoplanetary discs
• Rotating filament in Orion B: Do cores inherit their angular momentum from their parent filament?
• Investigating the Complex Velocity Structures within Dense Molecular Cloud Cores with GBT-Argus
• The highly variable time evolution of star-forming cores identified with dendrograms
• Droplets II: Internal Velocity Structures and Potential Rotational Motions in Pressure-dominated Coherent Structures
• Relative Alignment between Dense Molecular Cores and Ambient Magnetic Field: The Synergy of Numerical Models and Observations
• Evolution of the Angular Momentum of Molecular Cloud Cores Formed from Filament Fragmentation
• Search for Alignment of Disk Orientations in Nearby Star-Forming Regions: Lupus, Taurus, Upper Scorpius, $\rho$ Ophiuchi, and Orion
• Alignment of dense molecular core morphology and velocity gradients with ambient magnetic fields
• The Twisted Magnetic Field of the Protobinary L483
• Evolution and Kinematics of Protostellar Envelopes in the Perseus Molecular Cloud
• Core orientations and magnetic fields in isolated molecular clouds
• Prestellar Cores in Turbulent Clouds: Numerical Modeling and Evolution to Collapse
• Prestellar Cores in Turbulent Clouds: Properties of Critical Cores
• Magnetic field alignment with dense cores in the transition between cloud and core scales