Physics of Thermal Gaseous Nebulae

Aller, L. H.

doi:10.1007/978-94-010-9639-3

Cited by 336 publications

(120 citation statements)

References 0 publications

Supporting

Mentioning

117

Contrasting

Unclassified

Order By: Relevance

“…7 the error in the total [S ] population output by both NEBULAR and PyNeb. Figure 8 compares the emissivity of Hβ returned by NEBULAR with the one computed by PyNeb with the same interpolation formula (Aller 1984). The default emissivity used by PyNeb (Storey & Hummer 1995) is also displayed for reference, normalized to the Aller (1984) formula.…”

Section: Populations Emissivities and Physical Conditionsmentioning

confidence: 99%

“…Figure 8 compares the emissivity of Hβ returned by NEBULAR with the one computed by PyNeb with the same interpolation formula (Aller 1984). The default emissivity used by PyNeb (Storey & Hummer 1995) is also displayed for reference, normalized to the Aller (1984) formula. The wiggles are an artifact of the linear interpolation in the table; they indicate that a smooth interpolation would probably work better.…”

Section: Populations Emissivities and Physical Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

PyNeb: a new tool for analyzing emission lines

Luridiana

Morisset

Shaw

2014

A&A

524

409

View full text Add to dashboard Cite

Analysis of emission lines in gaseous nebulae yields direct measures of physical conditions and chemical abundances and is the cornerstone of nebular astrophysics. Although the physical problem is conceptually simple, its practical complexity can be overwhelming since the amount of data to be analyzed steadily increases; furthermore, results depend crucially on the input atomic data, whose determination also improves each year. To address these challenges we created PyNeb, an innovative code for analyzing emission lines. PyNeb computes physical conditions and ionic and elemental abundances and produces both theoretical and observational diagnostic plots. It is designed to be portable, modular, and largely customizable in aspects such as the atomic data used, the format of the observational data to be analyzed, and the graphical output. It gives full access to the intermediate quantities of the calculation, making it possible to write scripts tailored to the specific type of analysis one wants to carry out. In the case of collisionally excited lines, PyNeb works by solving the equilibrium equations for an n-level atom; in the case of recombination lines, it works by interpolation in emissivity tables. The code offers a choice of extinction laws and ionization correction factors, which can be complemented by user-provided recipes. It is entirely written in the python programming language and uses standard python libraries. It is fully vectorized, making it apt for analyzing huge amounts of data. The code is stable and has been benchmarked against IRAF/NEBULAR. It is public, fully documented, and has already been satisfactorily used in a number of published papers.

show abstract

Section: Populations Emissivities and Physical Conditionsmentioning

confidence: 99%

Section: Populations Emissivities and Physical Conditionsmentioning

confidence: 99%

PyNeb: a new tool for analyzing emission lines

Luridiana

Morisset

Shaw

2014

A&A

524

409

View full text Add to dashboard Cite

show abstract

“…Using the observed decrement of several hydrogen Balmer emission lines we corrected the line fluxes relative to the Hβ flux for two effects: (1) reddening adopting the extinction curve of Cardelli et al (1989) and (2) underlying hydrogen stellar absorption that is derived simultaneously by an iterative procedure as described in Izotov et al (1994). The extinction coefficients are defined as C(Hβ) = 1.47E(B−V ), where Aller 1984). The spectroscopic data were corrected for the aperture using the relation 2.5 r(app)−r , where r and r(app) are the SDSS r-band total magnitude and the magnitude within the round spectroscopic aperture, respectively.…”

Section: The Samplementioning

confidence: 99%

“…Then the SED with any star-formation history can be obtained by integrating the instantaneous burst SEDs over time with a specified time-varying star-formation rate. The SED of the gaseous continuum was taken from Aller (1984). It included hydrogen and helium free-bound, freefree, and two-photon emission.…”

Section: Spectral Energy Distribution (Sed) and The Galaxy's Stellar mentioning

confidence: 99%

On the universality of luminosity–metallicity and mass–metallicity relations for compact star-forming galaxies at redshifts 0 < z < 3

Izotov

Гусева

Fricke

et al. 2015

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We study relations between global characteristics of low-redshift (0 < z < 1) compact star-forming galaxies, including absolute optical magnitudes, Hβ emission-line luminosities (or equivalently star-formation rates), stellar masses, and oxygen abundances. The sample consists of 5182 galaxies with high-excitation H ii regions selected from the SDSS DR7 and SDSS/BOSS DR10 surveys adopting a criterion [O iii]λ4959/Hβ 1. These data were combined with the corresponding data for high-redshift (2 z 3) star-forming galaxies. We find that in all diagrams low-z and high-z star-forming galaxies are closely related indicating a very weak dependence of metallicity on stellar mass, redshift, and star-formation rate. This finding argues in favour of the universal character of the global relations for compact star-forming galaxies with high-excitation H ii regions over redshifts 0 < z < 3.

show abstract

“…This approach uses the weak [O III]λ4363 nebular emission line, which is governed by the ability of the gas to cool from a higher oxygen abundance, O/H (Aller 1984). Previous studies have been limited to the use of strong nebular emission lines for metallicity estimations.…”

Section: Introductionmentioning

confidence: 99%

The Metal Abundances Across Cosmic Time (     ) Survey. I. Optical Spectroscopy in the Subaru Deep Field

Ly¹,

Malhotra²,

Malkan³

et al. 2016

ApJS

View full text Add to dashboard Cite

Deep rest-frame optical spectroscopy is critical for characterizing and understanding the physical conditions and properties of the ionized gas in galaxies. Here, we present a new spectroscopic survey called "Metal Abundances across Cosmic Time" or  , which will obtain rest-frame optical spectra for ∼3000 emission-line galaxies. This paper describes the optical spectroscopy that has been conducted with MMT/Hectospec and Keck/DEIMOS for ≈1900 z = 0.1-1 emission-line galaxies selected from our narrowband and intermediate-band imaging in the Subaru Deep Field. In addition, we present a sample of 164 galaxies for which we have measured the weak [O III] λ4363 line (66 with at least 3σ detections and 98 with significant upper limits). This nebular emission line determines the gas-phase metallicity by measuring the electron temperature of the ionized gas. This paper presents the optical spectra, emission-line measurements, interstellar properties (e.g., metallicity, gas density), and stellar properties (e.g., star formation rates, stellar mass). Paper II of the  survey (Ly et al.) presents the first results on the stellar mass-gas metallicity relation at z1 using the sample with [O III]λ4363 measurements.

show abstract

Physics of Thermal Gaseous Nebulae

Cited by 336 publications

References 0 publications

PyNeb: a new tool for analyzing emission lines

PyNeb: a new tool for analyzing emission lines

On the universality of luminosity–metallicity and mass–metallicity relations for compact star-forming galaxies at redshifts 0 < z < 3

The Metal Abundances Across Cosmic Time (     ) Survey. I. Optical Spectroscopy in the Subaru Deep Field

Contact Info

Product

Resources

About