An unambiguous obseravtion of the radial expansion of the faint giant halo of the planetary nebula NGC 6826.
Abstract
Spatially resolved observations at high spectral resolution of the forbidden O III 5007-A line profiles from the faint, giant halo of the planetary nebula NGC 6826 have been obtained with the Manchester echelle spectrometer combined with the Isaac Newton Telescope. The observed profiles were fitted with single Gaussian line profiles. When the widths of the Gaussian profiles are plotted as a function of radius from the center of the halo of NGC 6826, a trend to smaller widths at higher radii is found, as expected for a radially expanding halo. The radial expansion velocity of the halo is found to be 9.8 km/s when modeled with a thin shell but about 13 km/s for a thick shell model. Comparison of the observed data to numerically simulated data suggests that the halo of NGC 6826 is more likely to be a thick shell than a thin shell.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 1992
- DOI:
- 10.1093/mnras/259.4.629
- Bibcode:
- 1992MNRAS.259..629B
- Keywords:
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- Astronomical Spectroscopy;
- Planetary Nebulae;
- Radial Distribution;
- Spectral Line Width;
- Astronomical Models;
- Brightness Distribution;
- Faint Objects;
- Astrophysics