LRD host galaxies show average metallicity 0.08 Z_sun with narrow stable range, challenging pristine-gas formation models while ruling out typical local AGN.
PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
9 Pith papers cite this work. Polarity classification is still indexing.
9
Pith papers citing it
abstract
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.
fields
astro-ph.GA 9years
2026 9verdicts
UNVERDICTED 9representative citing papers
76 N/O-enhanced galaxies at 4<z<8.5 are observed shortly after starbursts, either in the WR enrichment phase within 10 Myr or the AGB phase after 30-40 Myr following outflows.
JWST MIRI observations of 634 galaxies at 0.2<z<2 yield IR luminosity functions with faint-end slope α≈0.147, implying lower dust-obscured SFRD than previous ALMA/Herschel/Spitzer studies.
The Helix Nebula is a low-density, stratified object with near-solar oxygen abundance (8.7), a ~1 dex sulfur deficit, and moderate helium/nitrogen enrichment placing it near the Type I boundary, with abundance variations attributed to ionization structure rather than chemical inhomogeneity.
New Gemini/GNIRS observations of star-forming radio galaxies show warm H2 emission driven primarily by mergers rather than jets.
New spectroscopy and simulations of Arp 143 suggest it formed via head-on collision between S0 and Sc galaxies following a flyby.
Abundance analysis of 84 type-2 AGNs finds oversolar He and subsolar O at z>2.8, including one object at z=6.26 with record He abundance of 12+log(He/H)=11.64, plus marginal trends of declining He/H and rising O/H toward z=0.
Line ratio diagnostics in NGC 1068 indicate AGN outflows are shock-accelerated, with outflowing gas dust-free and 19-110 times denser than disk gas.
JWST spectra reveal that two z~7 galaxies already show near-solar iron-to-silicon ratios with no strong odd-even effect, favoring early Type Ia supernovae over pair-instability supernovae as the source of iron enrichment.
citing papers explorer
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The metallicities of little red dot host galaxies: LRDs are metal poor, but not pristine
LRD host galaxies show average metallicity 0.08 Z_sun with narrow stable range, challenging pristine-gas formation models while ruling out typical local AGN.
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Diverse Histories and Common Origins of Nitrogen-enhanced JWST Galaxies
76 N/O-enhanced galaxies at 4<z<8.5 are observed shortly after starbursts, either in the WR enrichment phase within 10 Myr or the AGB phase after 30-40 Myr following outflows.
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MEGA and SMILES Find Fewer Dusty Galaxies than Expected at Cosmic Noon
JWST MIRI observations of 634 galaxies at 0.2<z<2 yield IR luminosity functions with faint-end slope α≈0.147, implying lower dust-obscured SFRD than previous ALMA/Herschel/Spitzer studies.
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SDSS-V LVM: Revealing the Physical and Chemical Structure of the Helix Nebula
The Helix Nebula is a low-density, stratified object with near-solar oxygen abundance (8.7), a ~1 dex sulfur deficit, and moderate helium/nitrogen enrichment placing it near the Type I boundary, with abundance variations attributed to ionization structure rather than chemical inhomogeneity.
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When Jets Don't Quench: Near-Infrared H$_{2}$ in Star Forming Low-Excitation Radio Galaxies
New Gemini/GNIRS observations of star-forming radio galaxies show warm H2 emission driven primarily by mergers rather than jets.
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Unveiling a cosmic tango: Integral field spectroscopy and numerical simulations of Arp 143's interaction
New spectroscopy and simulations of Arp 143 suggest it formed via head-on collision between S0 and Sc galaxies following a flyby.
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Cosmic evolution of the helium and oxygen abundances in type 2 Active Galactic Nuclei: Helium-loud AGNs
Abundance analysis of 84 type-2 AGNs finds oversolar He and subsolar O at z>2.8, including one object at z=6.26 with record He abundance of 12+log(He/H)=11.64, plus marginal trends of declining He/H and rising O/H toward z=0.
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Dust destruction signals shock-accelerated outflows in the nearby active galaxy NGC 1068
Line ratio diagnostics in NGC 1068 indicate AGN outflows are shock-accelerated, with outflowing gas dust-free and 19-110 times denser than disk gas.
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JWST Absorption-Line Analysis of UV-Bright Galaxies at $z=7.2-10.6$: Early Chemical Enrichment Traced by C, O, Mg, Al, Si, and Fe
JWST spectra reveal that two z~7 galaxies already show near-solar iron-to-silicon ratios with no strong odd-even effect, favoring early Type Ia supernovae over pair-instability supernovae as the source of iron enrichment.