Filament Fragmentation in High-Mass Star Formation

Abstract

Aims: We resolve the length-scales for filament formation and fragmentation (res. <=0.1pc), in particular the Jeans length and cylinder fragmentation scale. Methods: We observed the prototypical high-mass star-forming filament IRDC18223 with the Plateau de Bure Interferometer (PdBI) in the 3.2mm continuum and N2H+(1-0) line emission in a ten field mosaic at a spatial resolution of ~4'' (~14000AU). Results: The dust continuum emission resolves the filament into a chain of at least 12 relatively regularly spaced cores. The mean separation between cores is ~0.40(+-0.18)pc. While this is approximately consistent with the fragmentation of an infinite, isothermal, gravitationally bound gas cylinder, a high mass-to-length ratio of M/l~1000M_sun/pc requires additional turbulent and/or magnetic support against radial collapse of the filament. The N2H+(1-0) data reveal a velocity gradient perpendicular to the main filament. Although rotation of the filament cannot be excluded, the data are also consistent with the main filament being comprised of several velocity-coherent sub-filaments. Furthermore, this velocity gradient perpendicular to the filament resembles recent results toward Serpens south that are interpreted as signatures of filament formation within magnetized and turbulent sheet-like structures. Lower-density gas tracers ([CI] and C18O) reveal a similar red/blueshifted velocity structure on scales around 60'' east and west of the IRDC18223 filament. This may tentatively be interpreted as a signature of the large-scale cloud and the smaller-scale filament being kinematically coupled. We do not identify a velocity gradient along the axis of the filament. This may either be due to no significant gas flows along the filamentary axis, but it may partly also be caused by a low inclination angle of the filament with respect to the plane of the sky that could minimize such signature.

12 pages, 9 figures, accepted for A&A, a higher-resolution version can be found at http://www.mpia.de/homes/beuther/papers.html

References in corpus (11)

• Fragmentation of Molecular Clumps and Formation of Protocluster
• On the nature of star-forming filaments: I. Filament morphologies
• Chains of dense cores in the Taurus L1495/B213 complex
• The dynamical properties of dense filaments in the infrared dark cloud G035.39-00.33
• The Perils of Clumpfind: The Mass Spectrum of Sub-structures in Molecular Clouds
• CARMA Large Area Star Formation Survey: Observational Analysis of Filaments in the Serpens South Molecular Cloud
• CARMA Large Area Star Formation Survey: Structure and Kinematics of Dense Gas in Serpens Main
• The Onset of Massive Star Formation: The Evolution of Temperature and Density Structure in an Infrared Dark Cloud
• The Role of Turbulence and Magnetic Fields in Simulated Filamentary Structure
• Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions
• On the fidelity of the core mass functions derived from dust column density data

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