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arXiv · astro-ph/9910377

H2 and Br-gamma narrow-band imaging of bipolar planetary nebulae

M. A. Guerrero·E. Villaver·A. Manchado·P. Garcia-Lario·F. Prada
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Abstract

We present near-IR narrow-band continuum-subtracted images in the H$_2$ $2.122μ$m, and Br$γ$ $2.166μ$m emission lines for a sample of 15 bipolar planetary nebulae. H$_2$ emission was definitely detected for most of the objects in this sample (13 out of 15). The very high H$_2$ detection rate supports the idea that bipolar planetary nebulae have important reservoirs of molecular material and offer suitable physical conditions for the excitation of H$_2$. The strength of the H$_2$ emission and the H$_2$/Br$γ$ flux ratio are found to correlate with the morphology of the bipolar nebulae observed. Bipolar PNe with broad and bright rings exhibit stronger H$_2$ emission than bipolar PNe with narrow twists. High-quality (sub-arcsec) [N~{\sc ii}] and H$α$ optical images have been used to compare the distribution of the ionized and molecular material. The H$_2$ emission lies just outside the optical [N~{\sc ii}] emission zone.

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M. A. Guerrero, E. Villaver, A. Manchado, P. Garcia-Lario, F. Prada. 1999-10-20. H2 and Br-gamma narrow-band imaging of bipolar planetary nebulae. https://doi.org/10.1086/313311

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