Magnetocentrifugal Launching of Jets from Accretion Disks. II. Inner Disk-driven Winds

By Ruben Krasnopolsky, Zhi-Yun Li, R. Blandford. 2003

161 citations recorded by the source corpus.

We numerically follow the time evolution of axisymmetric outflows magnetocentrifugally driven from the inner portion of accretion disks from their launching surface to large observable distances. Special attention is paid to the collimation of part of the outflow into a dense, narrow jet around the rotation axis after a steady state has been reached. For parameters typical of T Tauri stars, we define a fiducial "jet" as that outlined by the contour of constant density at 104 cm-3. We find that the jet, so defined, appears nearly cylindrical well above the disk, in agreement with previous asymptotic analyses. Closer to the equatorial plane, the density contour can either bulge outward or pinch inward, depending on the conditions at the launching surface, particularly the mass flux distribution. We find that even though a dense, jetlike feature is always formed around the axis, there is no guarantee that the high-density axial jet would dominate the more tenuous, wide-angle part of the wind. Specifically, on the 100 AU scale, resolvable by the Hubble Space Telescope and ground-based adaptive optics for nearby T Tauri winds, the fraction of the wind mass flux enclosed by the fiducial jet can vary substantially, again depending on the launching conditions. We show two examples in which the fraction is ~20% and ~45%. These dependences may provide a way to constrain the conditions at the launching surface, which are poorly known at present.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/3c0b61cce71a6bdcb8cb1270bb4e98d91143cb3c

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Citations in the corpus

Magnetically Driven Accretion in the Kerr Metric. III. Unbound Outflows (2004, background): “In such studies the focus is on the ability of this large-scale field to accelerate and collimate gas supplied by the disk boundary (e.g., Meier et al. 1997; Romanova et al. 1997; Ouyed & Pudritz 1997; Krasnopolsky et al. 1999).”
Global Simulations of the Inner Regions of Protoplanetary Disks with Comprehensive Disk Microphysics (2017, background): “…(e.g., Blandford & Payne 1982; Li 1995; Ferreira 1997) to local solutions that match them (e.g., Wardle & Koenigl 1993; Königl et al. 2010; Salmeron et al. 2011), as well as global simulations (e.g., Krasnopolsky et al. 1999; Pudritz et al. 2006; Zanni et al. 2007; Tzeferacos et al. 2009).”
LOCAL STUDY OF ACCRETION DISKS WITH A STRONG VERTICAL MAGNETIC FIELD: MAGNETOROTATIONAL INSTABILITY AND DISK OUTFLOW (2012, background): “…simulations either assume a razorthin disk treated as a boundary condition with artificial mass injection (e.g., Li 1995; Ouyed & Pudritz 1997; Krasnopolsky et al. 1999), or proceed with unresolved disk by adopting some forms of artificial diffusion, (e.g., Kato et al. 2002; Casse & Keppens…”
Asymmetric Supernovae from Magnetocentrifugal Jets (2001, background): “(See, e.g., the steady state simulations of Krasnopolsky et al. 1999.)”