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Astron. Astrophys. 358, 1058-1068 (2000)
Expansion velocities and dynamical ages of planetary nebulae *
K. Gesicki 1 and
A.A. Zijlstra 2
1 Centrum Astronomii UMK, ul. Gagarina 11, 87-100 Torun, Poland (gesicki@astri.uni.torun.pl)
2 Astrophysics Group, Physics Department, UMIST, P.O. Box 88, Manchester M60 1QD, UK (aaz@iapetus.phy.umist.ac.uk)
Received 24 February 2000 / Accepted 16 April 2000
Abstract
The [OIII ] expansion velocities are presented for
planetary nebulae in the Galactic Bulge and Halo, and in the
Sagittarius Dwarf spheroidal galaxy. The velocities are shown to
increase with the distance from the star, in agreement with
hydrodynamical models. Dynamical ages are derived from these
velocities and are corrected for the effects of post-AGB acceleration
and non-uniform velocities. Masses for the central stars are obtained
from relations between dynamical ages and stellar temperatures. The
stellar core mass distribution is narrow, peaking at 0.61
![[FORMULA]](img1.gif)
. This is higher than predicted for
the Bulge by initial-final mass relations, but consistent with the
local white dwarf mass distribution.
Key words: ISM: planetary nebulae:
general 
stars: white dwarfs
* Based on observations obtained at ESO
Send offprint requests to: K. Gesicki
Contents
- 1. Introduction
- 2. [OIII ] observations and sample selection
- 2.1. Bulge, disk and halo membership
- 2.2. Observations
- 3. Method of analysis
- 3.1. Computer codes
- 3.2. Model simplifications
- 3.3. Uniform velocities
- 3.4. Velocity gradients
- 4. Expansion velocities
- 5. Nebulae and their central stars
- 5.1. HR diagram
- 5.2. Dynamical ages
- 5.3. Masses of nebular cores
- 5.4. Comparison with white dwarf masses
- 6. Conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 2000
Online publication: June 20, 2000
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