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| Paper: |
Molecular Gas and Dust at the Center of the Egg Nebula |
| Volume: |
313, Asymmetrical Planetary Nebulae III |
| Page: |
355 |
| Authors: |
Lim, J.; Trung, D.-V. |
| Abstract: |
We present observations of the Egg Nebula in HC3N (5-4) and dust continuum at 7 mm with the VLA, made at an angular resolution of ~0.6". The HC3N molecular gas is distributed in a
shell with a radius of ~3" expanding at a velocity of ~18 km s-1, corresponding (at a distance of 1 kpc) to a dynamical age of ~800 yrs. This shell traces an earlier epoch when the mass loss from the central star was still spherically symmetric, but appears to have been partially disrupted, especially along the nebular
equatorial region, by the more recent bipolar molecular outflows discovered by Cox et al. (2000). A reconstruction of its 3-dimensional structure may provide insights as to the spatial orientation of the multiple bipolar outflows. By contrast, the dust is concentrated in
several clumps located inside the HC3N shell. These clumps are all located north of the central star, and appear to be quite closely aligned with the pair of northern searchlight beams. One clump is coincident with a near-infrared source inferred by Sahai et al. (1998a) to constitute a companion star. The nature of these dust clumps are a mystery. |
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