view Abstract Citations (23) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Quasi--one-dimensional Model for Narrow Astrophysical Jets Koupelis, T. ; van Horn, H. M. Abstract To investigate the coupling between rotation and magnetic fields as an acceleration mechanism in a jet, we develop a quasi-one-dimensional model for a narrow jet in which confinement of the rotating flow is produced by the tension of the magnetic field. The model is obtained by projecting the system of time-independent magnetohydrodynamic equations onto the axis of the jet. This is done in analogy with the projection of equations onto the equatorial plane in thin accretion disk models. The resulting three-parameter system consists of three first-order differential equations for the radius and velocity of the jet, together with algebraic relations for the remaining quantities of interest. We study the analytic structure of the equations and solve the system for the illustrative special case of a constant jet opening angle, using parameters appropriate to jets emanating from black holes, neutron stars, and protostars. For the black hole case, acceleration to v_max_ ~ 0.3c occurs over a distance of a few 100 AU from the source. At the 5 Mpc distance of Cen A, the closest extragalactic source with clear morphological jets, the minimum resolution needed to observe this "acceleration region" is ~0.03 mas, too small to be resolved by current VLBI measurements. Interestingly, the model leads naturally to a hollow jet, consistent with recent observations. For the neutron star case, using parameters appropriate to SS 433, the jet accelerates to v_max_ ~ 0.96c at a distance of 1.6 x 10^10^ cm, again in rough agreement with observations for this source. For the protostar case, the velocity reaches an asymptotic value only slightly greater than the injection velocity. Publication: The Astrophysical Journal Pub Date: July 1989 DOI: 10.1086/167583 Bibcode: 1989ApJ...342..146K Keywords: Astronomical Models; Black Holes (Astronomy); Computational Astrophysics; Radio Jets (Astronomy); Active Galactic Nuclei; Differential Equations; Magnetic Fields; Magnetohydrodynamics; Neutron Stars; Protostars; Astrophysics; BLACK HOLES; GALAXIES: JETS; GALAXIES: NUCLEI; HYDROMAGNETICS; ROTATION; STARS: PRE--MAIN-SEQUENCE full text sources ADS | data products SIMBAD (2) NED (1)