Plasma Diagnostics for Planetary Nebulae and H II Regions Using the N II and O II Optical Recombination Lines

Abstract

We carry out plasma diagnostic analyses for 123 planetary nebulae (PNe) and 42 H II regions using the N II and O II optical recombination lines (ORLs). New effective recombination coefficients for the N II and O II optical recombination spectra are used. These data were calculated under the intermediate coupling scheme for a number of electron temperature (Te) and density (Ne) cases. We used a new method to determine the Te and Ne for the nebular sample, combining the ORLs with the most reliable measurements for each ion and the predicted intensities that are based on the new atomic data. Uncertainties of the derived Te and Ne are estimated for each object. The diagnostic results from heavy element ORLs show reasonable agreement with previous calculations in the literature. We compare the electron temperatures derived from the N II and O II ORLs, Te(ORLs), and those from the collisionally excited lines (CELs), Te(CELs), as well as the hydrogen Balmer jump, Te(H I BJ), especially for the PNe with large abundance discrepancies. Temperatures from He I recombination lines, Te(He I), are also used for comparison if available. For all the objects included in our sample, Te(ORLs) are lower than Te(H I BJ), which are in turn systematically lower than Te(CELs). Nebulae with Te(He I) available show the relation Te(ORLs) < Te(He I) < Te(H I BJ) < Te(CELs), which is consistent with predictions from the bi-abundance nebular model postulated by Liu et al. (2000).

arXiv comment21 pages, 13 figures, accepted for publication in MNRAS

References in corpus (31)

• A reappraisal of the chemical composition of the Orion nebula based on VLT echelle spectrophotometry
• Improving Predictions for Helium Emission Lines
• Resolving the electron temperature discrepancies in HII Regions and Planetary Nebulae: kappa-distributed electrons
• The Chemical Composition of the Small Magellanic Cloud H II Region NGC 346 and the Primordial Helium Abundance
• Keck HIRES Spectroscopy of Extragalactic HII Regions: C and O Abundances from Recombination Lines
• Heavy elements in Galactic and Magellanic Cloud HII regions: recombination-line versus forbidden-line abundances
• The localized chemical pollution in NGC 5253 revisited: Results from deep echelle spectrophotometry
• A deep survey of heavy element lines in planetary nebulae - I. Observations and forbidden-line densities, temperatures and abundances
• Optical Recombination Lines of Heavy-elements in Giant Extragalactic HII Regions
• A deep survey of heavy element lines in planetary nebulae -- II. Recombination line abundances and evidence for ultra-cold plasma
• s-Process Abundances in Planetary Nebulae
• Faint emission lines in the Galactic H II regions M16, M20 and NGC 3603
• Chemical abundances for Hf 2-2, a planetary nebula with the strongest known heavy element recombination lines
• Chemical abundances of the Galactic H II region NGC 3576 derived from VLT echelle spectrophotometry
• Physical conditions in the planetary nebula Abell 30
• Elemental abundances of Galactic bulge planetary nebulae from optical recombination lines
• Integrated spectrum of the planetary nebula NGC 7027
• Deep Echelle Spectrophotometry of S 311, a galactic H II Region Outside the Solar Circle
• V605 Aql: The Older Twin of Sakurai's Object
• VLT Echelle Spectrophotometry of the Planetary Nebula NGC 5307 and Temperature Variations
• Helium recombination spectra as temperature diagnostics for planetary nebulae
• The hydrogen-deficient knot of the `born again' planetary nebula Abell 58 (V605 Aql)
• Integral field spectroscopy of planetary nebulae: mapping the line diagnostics and hydrogen-poor zones with VLT FLAMES
• Very deep spectroscopy of the bright Saturn Nebula NGC 7009 -- I. Observations and plasma diagnostics
• Observations and 3D photoionisation modelling of the Wolf-Rayet planetary nebula NGC 1501
• New effective recombination coefficients for nebular N II lines
• Three-dimensional chemically homogeneous and bi-abundance photoionization models of the "super-metal-rich" planetary nebula NGC 6153
• Identification and Characterization of Faint Emission Lines in the Spectrum of the Planetary Nebula IC 418
• Optical spectrum of the planetary nebula M 2-24
• Ionized gas diagnostics from protoplanetary discs in the Orion Nebula and the abundance discrepancy problem
• Recombination Line vs. Forbidden Line Abundances in Planetary Nebulae

Cited by in corpus (27)

• NGC 6778: Strengthening the link between extreme abundance discrepancy factors and central star binarity in planetary nebulae
• Analysis of chemical abundances in planetary nebulae with [WC] central stars. II. Chemical abundances and the abundance discrepancy factor
• S-process enrichment in the planetary nebula NGC 3918. Results from deep echelle spectrophotometry
• The Abundances of Light Neutron-Capture Elements in Planetary Nebulae III. The Impact of New Atomic Data on Nebular Selenium and Krypton Abundance Determinations
• Recombination coefficients for O II lines in nebular conditions
• C/O ratios in planetary nebulae with dual-dust chemistry from faint optical recombination lines
• A search for diffuse bands in fullerene planetary nebulae: evidence of diffuse circumstellar bands
• Very deep spectroscopy of the bright Saturn Nebula NGC 7009 - II. Analysis of the rich optical recombination spectrum
• Photoionized Herbig-Haro objects in the Orion Nebula through deep high-spectral resolution spectroscopy I: HH529II and III
• Densities, temperatures, pressures, and abundances derived from OII recombination lines in HII regions and their implications
• Chemical Abundances of Planetary Nebulae in the Substructures of M31
• Evidence for a [WR] or WEL-type binary nucleus in the bipolar planetary nebula Vy 1-2
• Carbon Abundances in Starburst Galaxies of the Local Universe
• The PNe and H II regions in NGC 6822 revisited. Clues to AGB nucleosynthesis
• Very Large Telescope deep echelle spectroscopy of Galactic planetary nebulae NGC 6153, M 1-42 and Hf 2-2
• Chemical Abundances of Planetary Nebulae in the Substructures of M31 -- II. The Extended Sample and A Comparison Study with the Outer-disk Group
• The kinematical behaviour of ORLs and CELs in Galactic PNe
• Evolution of Hen\,3-1357, the Stingray Nebula
• Physical and chemical properties of Wolf-Rayet planetary nebulae
• Physical conditions and chemical abundances in PN M 2-36. Results from deep echelle observations
• Physical conditions and chemical abundances in photoionized nebulae from optical spectra
• Abundance Discrepancy Factors in high density planetary nebulae
• Testing atomic collision theory with the two-photon continuum of astrophysical nebulae
• Physical Conditions and Chemical Abundances of the Variable Planetary Nebula IC 4997
• The kinematical behavior of ORLs and CELs in PNe with [WC] central star
• Close binary central stars and the abundance discrepancy - new extreme objects
• Evidence for cold plasma in planetary nebulae from radio observations with the LOw Frequency ARray (LOFAR)