ASTROPHYSICS: FINDINGS FROM M.G. ABRAHAMYAN ET AL IN ASTROPHYSICS REPORTED
Science Letter
September 30, 2008
"A vortical mechanism for generation of astrophysical jets is
proposed based on exact solutions of the hydrodynamic equations with
a generalized Rankine vortex. It is shown that the development of
a Rankine vortex in the polar layer of a rotating gravitating body
creates longitudinal fluxes of matter that converge toward the vortex
trunk, providing an exponential growth in the angular rotation velocity
of the trunk and a pressure drop on its axis," scientists writing in
the journal Astrophysics report (see also Astrophysics).
"The increased rotational velocity of the vortex trunk and the on-axis
pressure drop cease when the discontinuity in the azimuthal velocity at
the surface of the trunk reaches the sound speed. During this time,
ever deeper layers of the gravitating body are brought into the
vortical motion, while the longitudinal velocity of the flow along
the vortex trunk builds up, producing jet outflows of mass from its
surface," wrote M.G. Abrahamyan and colleagues.
The researchers concluded: "The resulting vortices are essentially
dissipationless."
Abrahamyan and colleagues published their study in Astrophysics
(Vortical mechanism for generation of astrophysical jets. Astrophysics,
2008;51(2):163-180).
Additional information can be obtained by contacting M.G. Abrahamyan,
Erevan State University, Yerevan, Armenia.
The publisher of the journal Astrophysics can be contacted at:
Springer, Plenum Publishers, 233 Spring St., New York, NY 10013, USA.