Nonradial and nonpolytropic astrophysical outflows VI. Overpressured winds and jets

Abstract

By means of a nonlinear separation of the variables in the governing full set of the magnetohydrodynamic (MHD) equations for axisymmetric plasmas we analyse an exact model for magnetized and rotating outflows which are hotter and overpressured at their axis. These outflows start subsonically and subAlfvénically from the central gravitating source and its surrounding accretion disk. Subsequently, they accelerate thermally and magnetocentrifugally and thus cross the appropriate MHD critical points, reaching high values of the Alfvén Mach number. Three types of solutions are found : (a) collimated jet-type outflows from efficient magnetic rotators with the flow confined by the magnetic hoop stress; (b) radially expanding wind-type outflows analogous to the solar wind, from inefficient magnetic rotators or strongly overpressured sources; (c) terminated solutions with increasing amplitude of oscillations in the width of the beam. In contrast to previously studied underpressured outflows, the transition from collimated jets to uncollimated winds is not continuous in the appropriate parametric space with a gap where no stationary solution is found. Superfast at infinity solutions are filtered by three critical surfaces corresponding to the three known limiting characteristics or separatrices of MHD wind theory. Collimated and terminated solutions cross the slow, Alfvén and fast magneto-acoustic critical points. Radially expanding solutions cross the slow and Alfvén critical points while the last boundary condition is imposed by requiring that the pressure vanishes at infinity.

arXiv commentreceived 2 December 2003 / accepted 8 April 2004

References in corpus (14)

• HST/STIS Spectroscopy of the Optical Outflow from DG Tau: Indications for Rotation in the Initial Jet Channel
• Magneto-Centrifugal Launching of Jets from Accretion Disks. I: Cold Axisymmetric Flows
• Heating and Ionization of X-Winds
• General Relativistic Simulations of Jet Formation in a Rapidly Rotating Black Hole Magnetosphere
• HST/STIS Observations of the Bipolar Jet from RW Aurigae: Tracing Outflow Asymmetries Close to the Source
• A disk-wind model with correct crossing of all MHD critical surfaces
• Radiatively inefficient MHD accretion-ejection structures
• Systematic construction of exact MHD models for astrophysical winds and jets
• Star Formation at High Angular Resolution
• Stationary accretion disks launching super fast-magnetosonic MHD jets
• Stellar winds, dead zones, and coronal mass ejections
• Magneto-Centrifugal Launching of Jets from Accretion Disks. II: Inner Disk-Driven Winds
• Nonradial and nonpolytropic astrophysical outflows. V. Acceleration and collimation of self-similar winds
• Collimation of a Central Wind by a Disk-Associated Magnetic Field

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• Three-dimensional MHD Simulations of Jets from Accretion Disks
• Nonradial and nonpolytropic astrophysical outflows IX. Modeling T Tauri jets with a low mass-accretion rate
• Relativistic spine jets from Schwarzschild black holes: "Application to AGN radioloud sources"
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• Application of a MHD hybrid solar wind model with latitudinal dependences to Ulysses data at minimum
• Long Term Simulations Of Astrophysical Jets; Energy Structure and Quasi-Periodic Ejection