Observing the onset of outflow collimation in a massive protostar
Journal article, 2015
The current paradigm of star formation through accretion disks, and magnetohydrodynamically driven gas ejections, predicts the development of collimated outflows, rather than expansion without any preferential direction. We present radio continuum observations of the massive protostar W75N(B)-VLA 2, showing that it is a thermal, collimated ionized wind and that it has evolved in 18 years from a compact source into an elongated one. This is consistent with the evolution of the associated expanding water-vapor maser shell, which changed from a nearly circular morphology, tracing an almost isotropic outflow, to an elliptical one outlining collimated motions. We model this behavior in terms of an episodic, short-lived, originally isotropic ionized wind whose morphology evolves as it moves within a toroidal density stratification.
Author
C. Carrasco-Gonzalez
Universidad Nacional Autonoma de Mexico
J. M. Torrelles
CSIC - Instituto de Ciencias del Espacio (ICE)
J. Canto
Universidad Nacional Autonoma de Mexico
S. Curiel
Universidad Nacional Autonoma de Mexico
G. Surcis
Joint Institute for VLBI in Europe
Wouter Vlemmings
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
H. J. van Langevelde
Joint Institute for VLBI in Europe
Leiden Observatory Research Institute
C. Goddi
Joint Institute for VLBI in Europe
Radboud University Nijmegen
G. Anglada
CSIC - Instituto de Astrofísica de Andalucía (IAA)
S. W. Kim
Korea Astronomy and Space Science Institute
University of Science and Technology (UST)
J. S. Kim
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
J. F. Gomez
CSIC - Instituto de Astrofísica de Andalucía (IAA)
Science
0036-8075 (ISSN)
Vol. 348 6230 114-117Magnetic fields and the outflows during the formation and evolution of stars (OUTFLOWMAGN)
European Commission (FP7) (EC/FP7/614264), 2014-05-01 -- 2019-04-30.
Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1126/science.aaa7216