Fragmentation of massive dense cores down to ~1000 AU: Relation between fragmentation and density structure

Abstract

In order to shed light on the main physical processes controlling fragmentation of massive dense cores, we present a uniform study of the density structure of 19 massive dense cores, selected to be at similar evolutionary stages, for which their relative fragmentation level was assessed in a previous work. We inferred the density structure of the 19 cores through a simultaneous fit of the radial intensity profiles at 450 and 850 micron (or 1.2 mm in two cases) and the Spectral Energy Distribution, assuming spherical symmetry and that the density and temperature of the cores decrease with radius following power-laws. We find a weak (inverse) trend of fragmentation level and density power-law index, with steeper density profiles tending to show lower fragmentation, and vice versa. In addition, we find a trend of fragmentation increasing with density within a given radius, which arises from a combination of flat density profile and high central density and is consistent with Jeans fragmentation. We considered the effects of rotational-to-gravitational energy ratio, non-thermal velocity dispersion, and turbulence mode on the density structure of the cores, and found that compressive turbulence seems to yield higher central densities. Finally, a possible explanation for the origin of cores with concentrated density profiles, which are the cores showing no fragmentation, could be related with a strong magnetic field, consistent with the outcome of radiation magnetohydrodynamic simulations.

accepted for publication in ApJ; a version with all (high resolution) figures is available at: http://www.ice.csic.es/files/palau/Palau14.pdf

References in corpus (15)

• The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive Forcing
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• Molecular Cloud Evolution II. From cloud formation to the early stages of star formation in decaying conditions
• The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X
• What determines the density structure of molecular clouds ? A case study of Orion B with Herschel
• Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit
• The Fragmentation of Magnetized, Massive Star-Forming Cores with Radiative Feedback
• Magnetic processes in a collapsing dense core. II Fragmentation. Is there a fragmentation crisis ?
• Multiple Jets from the High-Mass (Proto)stellar Cluster AFGL5142
• Molecular Line Emission from Massive Protostellar Disks: Predictions for ALMA and the EVLA
• Interferometric multi-wavelength (sub)millimeter continuum study of the young high-mass protocluster IRAS05358+3543
• Multi-line (sub)millimetre observations of the high-mass proto cluster IRAS 05358+3543
• Millimetre Continuum Observations of Southern Massive Star Formation Regions II. SCUBA observations of cold cores and the dust grain emissivity index $\beta$
• Dissipative structures of diffuse molecular gas III -- Small-scale intermittency of intense velocity-shears
• Submillimeter Observations of The Isolated Massive Dense Clump IRAS 20126+4104

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