Resumo

MEDINA, S.; PENA, M.; MORISSET, C.  e  STASIńSKA, G.. Galactic Planetary Nebulae with Wolf-Rayet Nuclei III: Kinematical Analysis of a Large Sample of Nebulae. Rev. mex. astron. astrofis [online]. 2006, vol.42, n.1, pp.53-74. ISSN 0185-1101.

Expansion velocities (V_exp) of different ions and line widths at the base of the lines are measured and analyzed for 24 PNe with [WC]-type nuclei (WRPNe), 9 PNe ionized by WELS (WLPNe) and 14 ordinary PNe. A comparative study of the kinematical behavior of the sample clearly demonstrates that WRPNe have on average 40-45% larger V_exp, and possibly more turbulence than WLPNe and ordinary PNe. WLPNe have velocity fields very much like the ones of ordinary PNe, rather than the ones of WRPNe. All the samples (WRPNe, WLPNe and ordinary o PNe) show expansion velocities increasing with age indicators, for example <V_exp> is larger for low-density nebulae and also it is larger for nebulae around high temperature stars. This age effect is much stronger for evolved WRPNe, suggesting that the [WC] winds have been accelerating the nebulae for a long time, while for non-WRPNe the acceleration seems to stop at some point when the star reaches a temperature of about 90,000 - 100,000 K. Non-WR nebulae reach a maximum V_exp ≤ 30 kms^-1 while evolved WRPNe reach maximum V_exp of about 40 kms^-1. For all kinds of objects (WRPNe and non-WRPNe) it is found that on average V_exp(N⁺) is slightly larger than V_exp(O⁺⁺), indicating that the nebulae present acceleration of the external shells.

Palavras-chave : PLANETARY NEBULAE; INDIVIDUAL [NGC 6369]; INDIVIDUAL [M 1-32]; INDIVIDUAL [BD+30°3639]; INDIVIDUAL [K 2-16]; STARS [WOLF-RAYET].

        · resumo em Espanhol     · texto em Inglês     · Inglês ( pdf )