The Kinematics of the Permitted C ii λ 6578 Line in a Large Sample of Planetary Nebulae

Journal Article · Wed Mar 01 04:00:00 EST 2017 · Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/AA5F53· OSTI ID:22663740

Richer, Michael G.; Suárez, Genaro; López, José Alberto

We present spectroscopic observations of the C ii λ 6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir. We study the kinematics of the C ii λ 6578 permitted line with respect to other permitted and collisionally excited lines. Statistically, we find that the kinematics of the C ii λ 6578 line are not those expected if this line arises from the recombination of C{sup 2+} ions or the fluorescence of C{sup +} ions in ionization equilibrium in a chemically homogeneous nebular plasma, but instead its kinematics are those appropriate for a volume more internal than expected. The planetary nebulae in this sample have well-defined morphology and are restricted to a limited range in H α line widths (no large values) compared to their counterparts in the Milky Way bulge; both these features could be interpreted as the result of young nebular shells, an inference that is also supported by nebular modeling. Concerning the long-standing discrepancy between chemical abundances inferred from permitted and collisionally excited emission lines in photoionized nebulae, our results imply that multiple plasma components occur commonly in planetary nebulae.

• OSTI ID: 22663740
• Journal Information: Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 3 Vol. 153; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BALMER LINES
CARBON IONS
COMPARATIVE EVALUATIONS
EQUILIBRIUM
FLUORESCENCE
LINE WIDTHS
MILKY WAY
MORPHOLOGY
PHOTOIONIZATION
PLANETARY NEBULAE
PLASMA
RECOMBINATION
RESOLUTION
TELESCOPES