CN Zeeman observations of the NGC 2264-C protocluster

Abstract

From an observational point of view, the role of magnetic fields in star formation remains unclear, and two main theoretical scenarios have been proposed so far to regulate the star-formation processes. The first model assumes that turbulence in star-forming clumps plays a crucial role, and especially that protostellar outflow-driven turbulence is crucial to support cluster-forming clumps; while the second scenario is based on the consideration of a magnetically-supported clump. Previous studies of the NGC 2264-C protocluster indicate that, in addition to thermal pressure, some extra support might effectively act against the gravitational collapse of this cluster-forming clump. We previously showed that this extra support is not due to the numerous protostellar outflows, nor the enhanced turbulence in this protocluster. Here we present the results of the first polarimetric campaign dedicated to quantifying the magnetic support at work in the NGC 2264-C clump. Our Zeeman observations of the CN(1-0) hyperfine lines provide an upper limit to the magnetic field strength B_los \leq0.6 mG in the protocluster (projected along the line of sight). While these results do not provide sufficiently tight constraints to fully quantify the magnetic support at work in NGC 2264-C, they suggest that, within the uncertainties, the core could be either magnetically super or sub-critical, with the former being more likely.

6 pages, 3 figures, to appear in Astronomy & Astrophysics

References in corpus (8)

• Slow Star Formation in Dense Gas: Evidence and Implications
• Magnetic Fields in Dark Cloud Cores: Arecibo OH Zeeman Observations
• Magnetic processes in a collapsing dense core. II Fragmentation. Is there a fragmentation crisis ?
• Optical polarimetry toward the Pipe nebula: Revealing the importance of the magnetic field
• Evolution of Magnetic Fields in High Mass Star Formation: Linking field geometry and collapse for the W51 e2/e8 cores
• Probing the formation of intermediate- to high-mass stars in protoclusters II. Comparison between millimeter interferometric observations of NGC 2264-C and SPH simulations of a collapsing clump
• XPOL - the correlation polarimeter at the IRAM 30m telescope
• Observations of the Goldreich-Kylafis effect in star-forming regions with XPOL at the IRAM 30m telescope

Cited by in corpus (4)

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• CN Zeeman and dust polarization in a high-mass cold clump
• Synthetic observations of first hydrostatic cores in collapsing low-mass dense cores II. Simulated ALMA dust emission maps
• Large-scale magnetic field in the Monoceros OB-1 East molecular cloud