Outflows and Jets from Collapsing Magnetized Cloud Cores

By Robi Banerjee, R. Pudritz. 2005

204 citations recorded by the source corpus.

Star formation is usually accompanied by outflow phenomena. There is strong evidence that these outflows and jets are launched from protostellar disks by magnetorotational processes. Here we report on our three-dimensional, adaptive mesh, magnetohydrodynamic simulations of collapsing, rotating, magnetized Bonnor-Ebert spheres, whose properties are taken directly from observations. In contrast to the pure hydro case, in which no outflows are seen, our present simulations show an outflow from the protodisk surface at ~130 AU and a jet at ~0.07 AU after a strong toroidal magnetic field buildup. The large-scale outflow, which extends up to ~600 AU at the end of our simulation, is driven by toroidal magnetic pressure (spring), whereas the jet is powered by magnetocentrifugal force (fling). At the final stage of our simulation these winds are still confined within two respective shock fronts. Furthermore, we find that the jet-wind and the disk-anchored magnetic field extract a considerable amount of angular momentum from the protostellar disk. The initial spin of our cloud core was chosen high enough to produce a binary system. We indeed find a close binary system (separation ~3 R☉), which results from the fragmentation of an earlier formed ring structure. The magnetic field strength in these protostars reaches ~3 kG and becomes about 3 G at 1 AU from the center, in agreement with recent observational results.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/2fd8cc8e20ad1caf5bf1f0dd5ba6665f330bc706

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Citations in the corpus

Gas- and dust evolution in protoplanetary disks (2010, background): “It should be noted that several groups perform 3D hydrodynamic simulations of collapsing cloud cores which show more complicated evolution (e.g.,Banerjee & Pudritz 2006; Whitehouse & Bate 2006).”
Magnetic Fields of Nondegenerate Stars (2009, methodology): “Detailed simulations have been carried out in recent years primarilyfor low-mass stars (e.g., Machida et al. 2004; Banerjee & Pudritz 2006; Hennebelle & Fromang 2008; Mellon & Li 2008), and in a few cases for massive stars as well (e.g., Banerjee & Pudritz 2007), mostly using numerical techniques…”
OUTFLOW FEEDBACK REGULATED MASSIVE STAR FORMATION IN PARSEC-SCALE CLUSTER-FORMING CLUMPS (2009, background): “Magnetic braking driven bubbles provide a form of energy feedback that should accompany any star formed in a magnetized cloud (e.g., Draine 1980; Tomisaka 1998; Banerjee & Pudritz 2006; Mellon & Li 2008; Hennebelle & Fromang 2008) but is absent from purely hydrodynamic models.”
A NEW JEANS RESOLUTION CRITERION FOR (M)HD SIMULATIONS OF SELF-GRAVITATING GAS: APPLICATION TO MAGNETIC FIELD AMPLIFICATION BY GRAVITY-DRIVEN TURBULENCE (2011, background): “…which are launched by a tower of magnetic pressure and/or by a centrifugal magnetic field (e.g., Blandford & Payne 1982; Pudritz & Norman 1983; Contopoulos 1995; Lynden-Bell 2003; Machida et al. 2006; Banerjee & Pudritz 2006, 2007; Duffin & Pudritz 2009, for theoretical work on jets and outflows)5.”
Disk formation during collapse of magnetized protostellar cores (2009, background): “Magnetohydrodynamic (MHD) simulations (e.g.; Machida et al. 2005, Banerjee & Pudritz 2006) find that even for modest values of the magnetic intensity, disk formation can be suppressed by magnetic braking (Shu et al. 1987, Mouschovias 1991, Basu & Mouschovias 1995, Galli et Send offprint requests…”
Collapse, outflows and fragmentation of massive, turbulent and magnetized prestellar barotropic cores (2011, background): “Although outflows and jets are a common feature of MHD collapse calculations (e.g. Machida et al. 2005, Banerjee & Pudritz 2006, Mellon & Li 2008, Hennebelle & Fromang 2008, Ciardi & Hennebelle 2010), which are thought to be caused by the magneto-centrifugal mechanism (e.g. Blandford & Payne 1982,…”
High- and Low-Velocity Magnetized Outflows in the Star Formation Process in a Gravitationally Collapsing Cloud (2008, methodology): “…1998, 2000, 2002;Burkert&Balsara 2001;Matsumoto & Tomisaka 2004; Machida et al. 2004, 2005a; Fromang et al. 2006;Banerjee&Pudritz 2006;Hennebelle&Fromang 2008) and that the high-velocity flow is driven from another core (Tomisaka 2002; Banerjee & Pudritz 2006; Machida et al. 2006a, 2007a).”
Theory of Star Formation (2007, background): “A prediction of these simulations is that a slow (v ∼ cs ∼ 0.2 km s−1) outflow should occur at large radii (∼ 103 AU; Tomisaka, 1998, 2002; Banerjee & Pudritz, 2006).”
Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit (2007, background): “…1979; Mestel & Paris 1979; Nakano 1989; Basu & Mouschovias 1994) or stopped shortly after a “seed” star has formed (Tomisaka 1998; Ziegler 2005; Banerjee & Pudritz 2006; Fromang, Hennebelle, & Teyssier 2006; Machida, Inutsuka, & Matsumoto 2007; see, how- ever, recent work by Hennebell &…”
THE INTERPLAY OF MAGNETIC FIELDS, FRAGMENTATION, AND IONIZATION FEEDBACK IN HIGH-MASS STAR FORMATION (2010, background): “…1982; Königl & Pudritz 2000), tower flows produced by wound up toroidal field (Tomisaka 1998, 2002; Matsumoto & Tomisaka 2004; Machida et al. 2004; Banerjee & Pudritz 2006, 2007) or interactions between the disk field and protostellar magnetosphere, either at an X-point (Najita & Shu 1994; Shu…”
Magnetic processes in a collapsing dense core I. Accretion and ejection (2007, background): “Indeed, Banerjee & Pudritz (2006) and Machida et al. (2006, 2007) found that a fast outflow, maybe a jet, having velocities around 30 km/s develops during the formation of the protostar.”
The effect of magnetic fields on star cluster formation (2008, background): “A related question which would be interesting to examine is how or whether the global magnetic field affects the frequency and/or streng h of jets and outflows in molecular clouds (e.g. Matsumoto & Tomisaka 2004; Banerjee & Pudritz 2006).”
RADIATION MAGNETOHYDRODYNAMIC SIMULATIONS OF PROTOSTELLAR COLLAPSE: PROTOSTELLAR CORE FORMATION (2012, methodology): “More detailed 3D simulations on this problem have been performed (Banerjee & Pudritz 2006; Hennebelle & Fromang 2008; Hennebelle & Teyssier 2008; Machida et al. 2008b) and effects of many physical ingredients such as misaligned magnetic fields (Matsumoto & Tomisaka 2004; Machida et al. 2006b;…”
H II REGIONS: WITNESSES TO MASSIVE STAR FORMATION (2010, background): “Collimated outflows from less massive protostars without H ii regions are likely magnetically driven, though (see e.g., Banerjee & Pudritz 2006).”
The impact of magnetic fields on single and binary star formation (2007, methodology): “This is in good agreement with a similar result found by Banerjee & Pudritz (2006) who considered only a collapse with a relatively low field strength, as here with the initial field aligned with the rotation axis.”