The tails in the Helix Nebula NGC 7293

Abstract

We have examined a stream-source model for the production of the cometary tails observed in the Helix Nebula NGC 7293 in which a transonic or moderately supersonic stream of ionized gas overruns a source of ionized gas. Hydrodynamic calculations reveal velocity structures which are in good agreement with the observational data on tail velocities and are consistent with observations of the nebular structure. The results also are indicative of a stellar atmosphere origin for the cometary globules. Tail remnants persist for timescales long enough for their identification with faint striations visible in the nebula gas to be plausible.

7 pages, 6 figures, accepted for publication in A&A

Cited by in corpus (9)

• The turbulent destruction of clouds - I. A k-epsilon treatment of turbulence in 2D models of adiabatic shock-cloud interactions
• Determination of the Physical Conditions of the Knots in the Helix Nebula from Optical and Infrared Observations
• VLT / Infrared Integral Field Spectrometer Observations of Molecular Hydrogen Lines in the Knots in the Planetary Nebula NGC 7293 (the Helix Nebula)
• Numerical simulations of shocks encountering clumpy regions
• Evidence for ablated flows in the shell of nova DQ Her
• Optical line profiles of the Helix planetary nebula (NGC 7293) to large radii
• CO in the C1 globule of the Helix nebula with ALMA
• Discovery of an Exceptional Optical Nebulosity in the Suspected Galactic SN Iax Remnant Pa 30 Linked to the Historical Guest Star of 1181 CE
• The generation of optical emission-line filaments in galaxy clusters