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The link between magnetic field orientations and star formation rates

An Author Correction to this article was published on 18 December 2017

An Erratum to this article was published on 17 July 2017

Abstract

Understanding star formation rates (SFRs) is a central goal of modern star formation models, which mainly involve gravity, turbulence and, in some cases, magnetic fields (B-fields)1,2. However, a connection between B-fields and SFRs has never been observed. Here, a comparison between the surveys of SFRs3,4 and a study of cloud–field alignment5—which revealed a bimodal (parallel or perpendicular) alignment—shows consistently lower SFRs per solar mass for clouds almost perpendicular to the B-fields. This is evidence of B-fields being a primary regulator of SFRs. The perpendicular alignment possesses a significantly higher magnetic flux than the parallel alignment and thus a stronger support of the gas against self-gravity. This results in overall lower masses of the fragmented components, which are in agreement with lower SFRs.

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Figure 1: Filamentary clouds and B-fields in the Pipe Nebula–Ophiuchus region.
Figure 2: SFR per unit mass versus cloud–field alignment for the Gould Belt clouds.
Figure 3: Illustration of how the magnetic flux of an elongated cloud can vary with the cloud–field alignment.

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Acknowledgements

The research was supported by the Hong Kong Research Grant Council, projects T12/402/13N, ECS24300314 and GRF14600915 and by the Chinese University of Hong Kong Direct Grant for Research, project 4053126 Analyzing Simulation Data of Star Formation. H.-b.L. appreciates the conference Star Formation in Different Environments 2016, where the discussion, especially with C. Matzner and J. D. Soler, inspired the direction we present in this work. Q.G. thanks Y. Wang for the discussion on Planck data analysis.

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Contributions

H.-b.L. designed and executed the experiment. H.J. and X.F. were in charge of the statistical tests. Q.G. and Y.Z. were responsible for the Planck data analysis.

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Correspondence to Hua-bai Li.

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The authors declare no competing financial interests.

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Supplementary Information

Supplementary Figures 1–5, Supplementary Table 1 and Supplementary References. (PDF 2452 kb)

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Li, Hb., Jiang, H., Fan, X. et al. The link between magnetic field orientations and star formation rates. Nat Astron 1, 0158 (2017). https://doi.org/10.1038/s41550-017-0158

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