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

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 $1.46\times 10^{-2}$ M${}_{\odot }$ and a dynamic age of 990yr. The column density of H I is estimated to be $7.1\times 10^{20}$ 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.

11 pages, 4 figures, Accepted for publication in ApJ

References in corpus (13)

• The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project
• HI-to-H2 Transitions and H I Column Densities in Galaxy Star-Forming Regions
• MASH-II: More Planetary Nebulae from the AAO/UKST HαSurvey
• Planetary Nebulae: Sources of Enlightenment
• One star, two star, red star, blue star: an updated planetary nebula central star distance catalogue from Gaia EDR3
• Reduction of the maximum mass-loss rate of OH/IR stars due to unnoticed binary interaction
• Molecular chemistry and the missing mass problem in PNe
• CO in the C1 globule of the Helix nebula with ALMA
• Determination of Planetary Nebulae angular diameters from radio continuum Spectral Energy Distribution modeling
• The ionised and molecular mass of post-common-envelope planetary nebulae. The missing mass problem
• An episodically variable stellar wind in the planetary nebula IC\,4997
• Abundance Discrepancy Factors in high density planetary nebulae
• Detection of CH${}^{+}$, CH and H${}_2$ molecules in the Young Planetary Nebula IC 4997

Cited by in corpus (1)

• FAST search for circumstellar atomic hydrogen. II. Is BD+303639 an interacting planetary nebula?