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arXiv · astro-ph/0607519

X-ray Observations of the Bipolar PNe NGC 2346 and NGC 7026

Abstract

We have obtained X-ray observations of the bipolar planetary nebulae (PNe) NGC 2346 and NGC 7026 with XMM-Newton. These observations detected diffuse X-ray emission from NGC 7026 but not from NGC 2346. The X-ray emission from NGC 7026 appears to be confined within the bipolar lobes of the PN and has spectral properties suggesting a thermal plasma emitting at a temperature of 1.1 +0.5/-0.2 times 10^6 K. The X-ray spectrum of NGC 7026 is modeled using nebular and stellar abundances to assess whether a significant amount of nebular material has been mixed into the shocked-wind, but the results of this comparison are not conclusive owing to the small number of counts detected. Observations of bipolar PNe indicate that diffuse X-ray emission is much less likely detected in open-lobed nebulae than closed-lobed nebulae, possibly because open-lobed nebulae do not have strong fast winds or are unable to retain hot gas.

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Robert A. Gruendl, Martin A. Guerrero, You-Hua Chu, Rosa M. Williams. 2006-07-22. X-ray Observations of the Bipolar PNe NGC 2346 and NGC 7026. https://arxiv.org/abs/astro-ph/0607519

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