Observing the onset of outflow collimation in a massive protostar
Abstract
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.
Keywords
Cite
@article{arxiv.1507.05285,
title = {Observing the onset of outflow collimation in a massive protostar},
author = {C. Carrasco-González and J. M. Torrelles and J. Cantó and S. Curiel and G. Surcis and W. H. T. Vlemmings and H. J. van Langevelde and C. Goddi and G. Anglada and S. -W. Kim and J. -S. Kim and J. F. Gómez},
journal= {arXiv preprint arXiv:1507.05285},
year = {2015}
}
Comments
See also Supplementary Materials (SupMat_carrasco-gonzalez_etal_astroph.pdf) within the source files