High-resolution spectra of the planetary nebula NGC 6803

Lee, S.-J.; Hyung, Siek

doi:10.1051/0004-6361/201219263

Cited by 4 publications

(2 citation statements)

References 34 publications

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“…ratios have been applied to planetary nebulae and local H ii regions (e.g., Aller et al 1970;Esteban, Peimbert & Torres-Peimbert 1999;Lee & Hyung 2013). The C iii] ratio traces high density, high pressure regions of the gas, and is less sensitive to metallicity than the other diagnostics.…”

Section: Ism Pressure and Electron Density Diagnosticsmentioning

confidence: 99%

Understanding Galaxy Evolution Through Emission Lines

Kewley

Nicholls

Sutherland

2019

Annu. Rev. Astron. Astrophys.

437

480

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We review the use of emission-lines for understanding galaxy evolution, focusing on excitation source, metallicity, ionization parameter, ISM pressure and electron density. We show that the UV, optical and infrared contain complementary diagnostics that can probe the conditions within different nebular ionization zones. In anticipation of upcoming telescope facilities, we provide new self-consistent emission-line diagnostic calibrations for complete spectral coverage from the UV to the infrared. These diagnostics can be used in concert to understand how fundamental galaxy properties have changed across cosmic time. We describe new 2D and 3D emission-line diagnostics to separate the contributions from star formation, AGN and shocks using integral field spectroscopy. We discuss the physics, benefits, and caveats of emissionline diagnostics, including the effect of theoretical model uncertainties, diffuse ionized gas, and sample selection bias. Accounting for complex density gradients and temperature profiles is critical for reliably estimating the fundamental properties of H ii regions and galaxies. Diffuse ionized gas can raise metallicity estimates, flatten metallicity gradients, and introduce scatter in ionization parameter measurements. We summarize with a discussion of the challenges and major opportunities for emission-line diagnostics in the coming years.

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Section: Ism Pressure and Electron Density Diagnosticsmentioning

confidence: 99%

Understanding Galaxy Evolution Through Emission Lines

Kewley

Nicholls

Sutherland

2019

Annu. Rev. Astron. Astrophys.

437

480

View full text Add to dashboard Cite

show abstract

“…The [N I] ratio was first calibrated as a density diagnostic by Dopita et al (1976). The [N I] λ5198, 5200 doublet is weak (∼ 1 × 10 −4 ×Hβ) for ionization parameters and metallicities typical of star-forming galaxies, and has been traditionally measured in planetary nebulae (e.g., Lee & Hyung 2013). However, with high resolution, high S/N spectroscopy, it is possible to observe this ratio in H II regions (e.g., Esteban et al 1999), allowing one to probe the H II region outer recombination zones at the interface between H I and H II regions.…”

Section: The [N I] Ratiomentioning

confidence: 99%

Theoretical ISM Pressure and Electron Density Diagnostics for Local and High-redshift Galaxies

Kewley

Nicholls

Sutherland

et al. 2019

ApJ

104

129

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We derive new self-consistent theoretical UV, optical, and IR diagnostics for the ISM pressure and electron density in the ionized nebulae of star-forming galaxies. Our UV diagnostics utilize the intercombination, forbidden and resonance lines of silicon, carbon, aluminum, neon, and nitrogen. We also calibrate the optical and IR forbidden lines of oxygen, argon, nitrogen and sulfur. We show that line ratios used as ISM pressure diagnostics depend on the gas-phase metallicity with a residual dependence on the ionization parameter of the gas. In addition, the traditional electron density diagnostic [S II] λ6731/[S II] λ6717 is strongly dependent on the gas-phase metallicity. We show how different emission-line ratios are produced in different ionization zones in our theoretical nebulae. The [S II] and [O II] ratios are produced in different zones, and should not be used interchangeably to measure the electron density of the gas unless the electron temperature is known to be constant. We review the temperature and density distributions observed within H II regions and discuss the implications of these distributions on measuring the electron density of the gas. Many H II regions contain radial variations in density. We suggest that the ISM pressure is a more meaningful quantity to measure in H II regions or galaxies. Specific combinations of line ratios can cover the full range of ISM pressures (4 < log(P/k) < 9). As H II regions become resolved at increasingly high redshift through the next generation telescopes, we anticipate that these diagnostics will be important for understanding the conditions around the young, hot stars from the early universe to the present day.

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Catalogue of the central stars of planetary nebulae

Weidmann

Mari

Schmidt

et al. 2020

A&A

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Planetary nebulae represent a potential late stage of stellar evolution, however, their central stars (CSPNe) are relatively faint and, therefore, pertinent information is available for merely < 20% of the Galactic sample. Consequently, the literature was surveyed to construct a new catalogue of 620 CSPNe featuring important spectral classifications and information. The catalogue supersedes the existing iteration by 25% and includes physical parameters such as luminosity, surface gravity, temperature, magnitude estimates, and references for published spectra. The marked statistical improvement enabled the following pertinent conclusions to be determined: the H-rich/H-poor ratio is 2:1, there is a deficiency of CSPNe with types [WC 5-6], and nearly 80% of binary central stars belong to the H-rich group. The last finding suggests that evolutionary scenarios leading to the formation of binary central stars interfere with the conditions required for the formation of H-poor CSPN. Approximately 50% of the sample with derived values of log L⋆, log Teff, and log g, exhibit masses and ages consistent with single stellar evolutionary models. The implication is that single stars are indeed able to form planetary nebulae. Moreover, it is shown that H-poor CSPNe are formed by higher mass progenitors. The catalogue is available through the Vizier database.

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High-resolution spectra of the planetary nebula NGC 6803

Cited by 4 publications

References 34 publications

Understanding Galaxy Evolution Through Emission Lines

Understanding Galaxy Evolution Through Emission Lines

Theoretical ISM Pressure and Electron Density Diagnostics for Local and High-redshift Galaxies

Catalogue of the central stars of planetary nebulae

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