HST STIS Observations of the Mixing Layer in the Cat’s Eye Nebula

DOI: 
10.3847/2041-8205/822/1/L19
Publication date: 
01/05/2016
Main author: 
Fang, Xuan
IAA authors: 
Fang, Xuan;Toalá, Jesús A.
Authors: 
Fang, Xuan;Guerrero, Martín A.;Toalá, Jesús A.;Chu, You-Hua;Gruendl, Robert A.
Journal: 
The Astrophysical Journal
Publication type: 
Article
Volume: 
822
Pages: 
L19
Abstract: 
Planetary nebulae (PNe) are expected to have a ∼10<SUP>5</SUP> K interface layer between the ≥slant 10<SUP>6</SUP> K inner hot bubble and the ∼10<SUP>4</SUP> K optical nebular shell. The PN structure and evolution, and the X-ray emission, depend critically on the efficiency of the mixing of material at this interface layer. However, neither its location nor its spatial extent have ever been determined. Using high-spatial resolution HST STIS spectroscopic observations of the N v λ λ 1239,1243 lines in the Cat’s Eye Nebula (NGC 6543), we have detected this interface layer and determined its location, extent, and physical properties for the first time in a PN. We confirm that this interface layer, as revealed by the spatial distribution of the N v λ1239 line emission, is located between the hot bubble and the optical nebular shell. We estimate a thickness of 1.5× {10}<SUP>16</SUP> cm and an electron density of ∼200 cm<SUP>−3</SUP> for the mixing layer. With a thermal pressure of ∼2 × 10<SUP>−8</SUP> dyn cm<SUP>−2</SUP>, the mixing layer is in pressure equilibrium with the hot bubble and ionized nebular rim of NGC 6543.Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. The observations are associated with program #12509.
Database: 
ADS
WOK
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2016ApJ...822L..19F/abstract
ADS Bibcode: 
2016ApJ...822L..19F
Keywords: 
planetary nebulae: general;planetary nebulae: individual: NGC 6543;stars: winds;outflows;X-rays: ISM;Astrophysics - Solar and Stellar Astrophysics;Astrophysics - Astrophysics of Galaxies