Bibcode
Dobrincic, Martina; Villaver, Eva; Guerrero, Martín A.; Manchado, A.
Referencia bibliográfica
Planetary Nebulae in our Galaxy and Beyond, Proceedings of the International Astronomical Union, Symposium #234. Edited by Michael J. Barlow and Roberto H. Méndez. Cambridge: Cambridge University Press, 2006., pp.387-388
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2006
Número de citas
1
Número de citas referidas
1
Descripción
Bipolar planetary nebulae (BPNe) offer a unique opportunity to test
models that aim to reproduce the PNe morphologies. In particular,
kinematic studies of BPNe allow a reconstruction of the 3D structure of
the nebula, otherwise hidden in imaging studies. With this aim in mind
we have obtained long-slit echelle spectra of a sample of PNe which
cover the full range of observed bipolar morphologies, from elliptical
to highly collimated. The analysis of our kinematical data reveals
equatorial expansion velocities in the low to medium range (3 to 16 km
s-1), while the polar expansion velocities range from 18 to
100 km s-1. We find that the kinematics of the PN K 3-46 can
only be explained by a decrease in the expansion velocity with time. The
kinematical ages, calculated by using distances estimated from Galactic
rotation curves, when available, or by using statistical values, show
that the BPNe in our sample - even those which show non-extreme
collimation - appear to be young. We have compared our results with the
latest theoretical models of BPN formation, and find good agreement
between the observed expansion velocities and the numerical models that
use magnetic fields coupled with stellar rotation as the collimation
mechanism.