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arXiv · 2205.06170

FAST search for circumstellar atomic hydrogen--I: the young planetary nebula IC 4997

Xu-Jia Ouyang·Yong Zhang·Albert Zijlstra·Chuan-Peng Zhang·Jun-ichi Nakashima·Quentin A Parker
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Abstract

Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Guizhou, China, we detect the 21cm neutral atomic hydrogen absorption in the young planetary nebula IC 4997. The absorption arises from a shell also associated with Na I D lines. The H I shell has a mass of $1.46\times10^{-2}$ M$_\odot$ and a dynamic age of 990yr. The column density of H I is estimated to be $7.1\times10^{20}$ cm$^{-2}$, which can be well explained in terms of a photodissociation region around the ionized nebula, limited by self shielding of H$_2$. We find that the atomic-to-ionized hydrogen ratio is 0.6, suggesting that H I substantially contributes to overall nebular mass.

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Xu-Jia Ouyang, Yong Zhang, Albert Zijlstra, Chuan-Peng Zhang, Jun-ichi Nakashima, Quentin A Parker. 2022-05-12. FAST search for circumstellar atomic hydrogen--I: the young planetary nebula IC 4997. https://doi.org/10.3847/1538-4357/ac6fdb

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