The current research of planetary nebulae distance measurement
Abstract
Planetary Nebula is an important tracer of Galactic chemical history and evolution, star and interstellar evolution. Distance as a basic physical parameter of planetary nebula, is crucial to study its size, luminosity, ionized mass, formation rate, space density and Galactic distribution. Distance of planetary nebula has been studied for several decades, but most of their distances are not well determined, e.g. only thirty-one planetary nebulae have distance measurement with uncertainty within 20%. We summarize major distance measurement methods of planetary nebulae, i.e., trigonometric parallax, cluster member, expansion parallax, spectroscopic parallax, reddening, Na D absorption, determinations of central star gravities, Shklovsky method, kinematics method, and then discuss the limitations and applications scope of each method in detail. Actually, applying different methods to the same planetary nebulae can have a huge difference in distance, and even the same method can lead to great difference for the same planetary nebula. We focus on the kinematics method applied to planetary nebulae either seriously effected by Galactic extinction or having no observable centra star but being radio bright. The kinematics distance has been used in our on-going project of radio planetary nebulae distance measurement.
- Publication:
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Progress in Astronomy
- Pub Date:
- August 2015
- Bibcode:
- 2015PrA....33..284Y
- Keywords:
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- planetary nebulae;
- distance measurement methods;
- kinematic distances;
- HI absorption