The Shapes of Molecular Cloud Cores in Simulations and Observations

Abstract

In this study, we investigate the shapes of starless and protostellar cores using hydrodynamic, self-gravitating adaptive mesh refinement simulations of turbulent molecular clouds. We simulate observations of these cores in dust emission, including realistic noise and telescope resolution, and compare to the observed core shapes measured in Orion by Nutter & Ward-Thompson (2007). The simulations and the observations have generally high statistical similarity, with particularly good agreement between simulations and Orion B. Although protostellar cores tend to have semi-major axis to semi-minor axis ratios closer to one, the distribution of axis ratios for starless and protostellar cores are not significantly different for either the actual observations of Orion or the simulated observations. Because of the high level of agreement between the non-magnetic hydrodynamic simulations and observation, contrary to a number of previous authors, one cannot infer the presence of magnetic fields from core shape distributions.

7 pages, accepted for publication in the ApJ

References in corpus (7)

• Theory of Star Formation
• A SCUBA survey of Orion, the low-mass end of the core mass function
• Comparing Star Formation on Large Scales in the c2d Legacy Clouds: Bolocam 1.1 mm Dust Continuum Surveys of Serpens, Perseus, and Ophiuchus
• Driven and Decaying Turbulence Simulations of Low-Mass Star Formation: From Clumps to Cores to Protostars
• The Kinematics of Molecular Cloud Cores in the Presence of Driven and Decaying Turbulence: Comparisons with Observations
• Formation and Collapse of Nonaxisymmetric Protostellar Cores in Planar Magnetic Interstellar Clouds: Formulation of the Problem and Linear Analysis
• The Shapes of Molecular Cloud Cores in Orion

Cited by in corpus (12)

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• Quantifying Observational Projection Effects Using Molecular Cloud Simulations
• Probing the Protostellar Envelope around L1157: the Dust and Gas Connection
• Protostellar collapse of magneto-turbulent cloud cores: shape during collapse and outflow formation
• Prestellar and protostellar cores in Ori B9
• Dense cores and star formation in the giant molecular cloud Vela~C
• Alignment of dense molecular core morphology and velocity gradients with ambient magnetic fields
• The Equilibrium Structure of Prolate Magnetized Molecular Cores
• Adaptive image ray-tracing for astrophysical simulations
• Non-similar collapse of singular isothermal spherical molecular cloud cores with nonzero initial velocities
• Prestellar Cores in Turbulent Clouds: Properties of Critical Cores
• Morphological Complexity of Protostellar Envelopes