Observational implications of precessing protostellar discs and jets

By Matthew R. Bate, Ian A. Bonnell, C. Clarke, S. Lubow, Gordon I. Ogilvie, J. Pringle, C. Tout. 2000

151 citations recorded by the source corpus.

We consider the dynamics of a protostellar disc in a binary system where the disc is misaligned with the orbital plane of the binary, with the aim of determining the observational consequences for such systems. The disc wobbles with a period approximately equal to half the orbital period of the binary and precesses on a longer time-scale. We determine the characteristic time-scale for realignment of the disc with the orbital plane as a result of dissipation. If the dissipation is determined by a simple isotropic viscosity then we find, in line with previous studies, that the alignment time-scale is of the order of the viscous evolution time-scale. However, for typical protostellar disc parameters, if the disc tilt exceeds the opening angle of the disc, then tidally induced shearing within the disc is transonic. In general, hydrodynamic instabilities associated with the internally driven shear result in extra dissipation that is expected to drastically reduce the alignment time-scale. For large disc tilts the alignment time-scale is then comparable with the precession time-scale, while for smaller tilt angles δ, the alignment time-scale varies as (sin δ)−1. We discuss the consequences of the wobbling, precession and rapid realignment for observations of protostellar jets and the implications for binary star formation mechanisms.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/c40aa5774d6dfb5aa493d58f66be9de2f948277d

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Citations in the corpus

THE FORMATION OF LOW-MASS BINARY STAR SYSTEMS VIA TURBULENT FRAGMENTATION (2010, background): “However, this can plausibly be explained via tidal circularization of initially misaligned systems (e.g. Lubow & Ogilvie 2000; Bate et al. 2000), so these binaries may have formed by either turbulent or disk fragmentation.”
Disintegrating Multiple Systems in Early Stellar Evolution (2000, background): “Altogether, the deÐnition and long-term stability of a jet axis in a binary system is an issue that calls for more observations of disk orientations (e.g., Monin, &Me nard, Duchene 1998 ; Jensen, Donar, & Mathieu 2000) and further detailed theoretical study (e.g., Bate et al. 2000).”
Tearing up the disc: misaligned accretion on to a binary (2013, background): “The analysis of King et al. (2005) also holds for circumbinary discs (Nixon et al. 2011b), where the disc precession is now due to the non-spherical gravitational field of the binary (e.g. Ivanov, Papaloizou & Polnarev 1999; Bate et al. 2000; Nixon et al. 2011b).”
The nature of SS433 and the ultraluminous X-ray sources (2006, background): “Disc nodding with this period is a direct effect of the m = 2 part of the tidal torque (Katz et al. 1982; Bate et al. 2000) acting on the outer part of the disc.”
PLANET HUNTERS: A TRANSITING CIRCUMBINARY PLANET IN A QUADRUPLE STAR SYSTEM (2012, background): “Bate et al. (2000) predict that circumstellar disks around binaries with a < 100 AU should be coplanar to the orbit of the binary.”