Magnetically regulated fragmentation of a massive, dense, and turbulent clump

¹ INAF–Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Florence, Italy
e-mail: fontani@arcetri.astro.it
² École Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, Université Lyon I, 46 allée d’Italie, 69364 Lyon Cedex 07, France
³ Max-Planck-Institut für Radioastronomie, auf dem Hügel 69, 53121 Bonn, Germany
⁴ I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
⁵ European Southern Observatory, Karl-Schwarzschild-Str 2, 85748 Garching bei München, Germany
⁶ Gothenburg Center for Advance Studies in Science and Technology, Chalmers University of Technology and University of Gothenburg, 412 96 Gothenburg, Sweden
⁷ INAF–Istituto di Radioastronomia and Italian ALMA Regional Centre, via P. Gobetti 101, 40129 Bologna, Italy
⁸ Max-Planck-Institüt für extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching bei München, Germany
⁹ International Center for Radio Astronomy Research, M468, University of Western Australia, 35, Stirling Hwy, Crawley, Western Australia 6009, Australia
¹⁰ Astrophysics Research Institute, Liverpool John Moores University, Liverpool, L3 5RF, UK
¹¹ CSIRO Astronomy and Space Science, 26 Dick Perry Avenue, Kensington WA 6151, Australia
¹² Observatorio Astronomico Nacional (IGN), Alfonso XII, 3 y 5, 28014 Madrid, Spain
¹³ Departments of Astronomy & Physics, University of Florida, Gainesville, FL 32611, USA

Received: 31 July 2016
Accepted: 27 August 2016

Abstract

Massive stars, multiple stellar systems, and clusters are born of the gravitational collapse of massive, dense, gaseous clumps, and the way these systems form strongly depends on how the parent clump fragments into cores during collapse. Numerical simulations show that magnetic fields may be the key ingredient in regulating fragmentation. Here we present ALMA observations at ~ 0.25′′ resolution of the thermal dust continuum emission at ~ 278 GHz towards a turbulent, dense, and massive clump, IRAS 16061–5048c1, in a very early evolutionary stage. The ALMA image shows that the clump has fragmented into many cores along a filamentary structure. We find that the number, the total mass, and the spatial distribution of the fragments are consistent with fragmentation dominated by a strong magnetic field. Our observations support the theoretical prediction that the magnetic field plays a dominant role in the fragmentation process of massive turbulent clumps.