Bibcode
Acker, A.; Gesicki, K.; Grosdidier, Y.; Durand, S.
Referencia bibliográfica
Astronomy and Astrophysics, v.384, p.620-628 (2002)
Fecha de publicación:
3
2002
Revista
Número de citas
39
Número de citas referidas
34
Descripción
Through a high-resolution spectroscopic survey, we analyze the velocity
field of 16 planetary nebulae with [WC]- or wels-type nuclei in
comparison with 8 nebulae having other central star types. We found
spectral evidence for finite turbulent velocities in [WC]-type planetary
nebulae superimposed on an essentially constant expansion velocity
pattern. The nebulae around O-type stars show no evidences for
significant turbulence while their expansion velocity is found to
increase outwards. Both types of nebulae show the same mean expansion
velocity. Our results support the earlier suggestions that nebulae
surrounding [WC] central stars are likely related to long-lasting
momentum-driven phase bubbles. Turbulence in the nebulae can be either
triggered, or enhanced, by stellar wind inhomogeneities that appear
ubiquitous in Wolf-Rayet nuclei. Based on observations obtained at the
European Southern Observatory and the Observatoire de Haute Provence.