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 Autónoma de México
J. M. Torrelles
Institute of Space Sciences (ICE) - CSIC
J. Canto
Universidad Nacional Autónoma de México
S. Curiel
Universidad Nacional Autónoma de México
G. Surcis
Joint Institute for VLBI in Europe (JIVE)
Wouter Vlemmings
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
H. J. van Langevelde
Joint Institute for VLBI in Europe (JIVE)
Leiden University
C. Goddi
Joint Institute for VLBI in Europe (JIVE)
Radboud University
G. Anglada
Institute of Astrophysics of Andalusia (IAA)
S. W. Kim
University of Science and Technology (UST)
Korea Astronomy and Space Science Institute
J. S. Kim
National Astronomical Observatory of Japan
J. F. Gomez
Institute of Astrophysics of Andalusia (IAA)
Science
0036-8075 (ISSN) 1095-9203 (eISSN)
Vol. 348 6230 114-117Magnetic fields and the outflows during the formation and evolution of stars (OUTFLOWMAGN)
European Commission (EC) (EC/FP7/614264), 2014-05-01 -- 2019-04-30.
Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1126/science.aaa7216