Skip to main content


Author(s): Chen, Che-Yu; Ostriker, Eve C

To refer to this page use:
Abstract: In giant molecular clouds (GMCs), shocks driven by converging turbulent flows create high-density, strongly magnetized regions that are locally sheetlike. In previous work, we showed that within these layers, dense filaments and embedded self-gravitating cores form by gathering material along the magnetic field lines. Here, we extend the parameter space of our three-dimensional, turbulent MHD core formation simulations. We confirm the anisotropic core formation model we previously proposed and quantify the dependence of median core properties on the pre-shock inflow velocity and upstream magnetic field strength. Our results suggest that bound core properties are set by the total dynamic pressure (dominated by large-scale turbulence) and thermal sound speed c(s) in GMCs, independent of magnetic field strength. For models with a Mach number between 5 and 20, the median core masses and radii are comparable to the critical Bonnor-Ebert mass and radius defined using the dynamic pressure for P-ext. Our results correspond toM(core) = 1.2c(s)(4)(G(3)rho(0)nu(2)(0))(-1/2) and R-core = 0.34c(s)(2)(G rho(0)nu(2)(0))(-1/2) for rho(0) and nu(0), the large-scale mean density and velocity. For our parameter range, the medianM(core) similar to 0.1-1M(circle dot), but a very high pressure cloud could have lower characteristic core mass. We find cores and filaments form simultaneously, and filament column densities are a factor of similar to 2 greater than the surrounding cloud when cores first collapse. We also show that cores identified in our simulations have physical properties comparable to those observed in the Perseus cloud. Superthermal cores in our models are generally also magnetically supercritical, suggesting that the same may be true in observed clouds.
Publication Date: 10-Sep-2015
Citation: Chen, Che-Yu, Ostriker, Eve C. (2015). ANISOTROPIC FORMATION OF MAGNETIZED CORES IN TURBULENT CLOUDS. ASTROPHYSICAL JOURNAL, 810 (10.1088/0004-637X/810/2/126
DOI: doi:10.1088/0004-637X/810/2/126
ISSN: 0004-637X
EISSN: 1538-4357
Related Item:
Type of Material: Journal Article
Journal/Proceeding Title: ASTROPHYSICAL JOURNAL
Version: Final published version. Article is made available in OAR by the publisher's permission or policy.

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.