Results 21 to 30 of about 954,000 (309)
Chemical abundances in Seyfert galaxies – VIII. Argon abundance estimates [PDF]
Monthly Notices of the Royal Astronomical Society, 2021 ABSTRACT For the first time, the argon abundance relative to hydrogen abundance (Ar/H) in the narrow line region of a sample of Seyfert 2 nuclei has been derived. In view of this, optical narrow emission line intensities of a sample of 64 local Seyfert 2 nuclei (z < 0.25) taken from Sloan Digital Sky Survey DR7 and measured by the
A F Monteiro, O L Dors
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Chemical abundances in active galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2020 ABSTRACT The Sloan Digital Sky Survey (SDSS) has proved to be a powerful resource for understanding the physical properties and chemical composition of star-forming galaxies in the local Universe. The SDSS population of active galactic nuclei (AGNs) remains as of yet less explored in this capacity.
Flury, Sophia R., Moran, Edward C.
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Abundance of field galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2015 15 pages, 13 figures.
Klypin, Anatoly +3 more
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The Metallicity and Distance of Leo A from Blue Supergiants
The Astrophysical Journal, 2023 We have obtained high-quality spectra of blue supergiant candidates in the dwarf irregular galaxy Leo A with the Low Resolution Imaging Spectrometer at the Keck I telescope.
Miguel A. Urbaneja +2 more
doaj +1 more source
Understanding the Chemical Evolution of Blue Edge-on Low Surface Brightness Galaxies
The Astrophysical Journal, 2023 We present a sample of 330 blue edge-on low surface brightness galaxies (ELSBGs). To understand the chemical evolution of ELSBGs, we derived the gas-phase abundance and the [ α /Fe] ratio.
Tian-wen Cao +6 more
doaj +1 more source
Robust Data-driven Metallicities for 175 Million Stars from Gaia XP Spectra
The Astrophysical Journal Supplement Series, 2023 We derive and publish data-driven estimates of stellar metallicity [M/H] for ∼175 million stars with low-resolution XP spectra published in Gaia DR3.
René Andrae +2 more
doaj +1 more source
Abundance ratios in dwarf elliptical galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2017 We determine abundance ratios of 37 dwarf ellipticals (dEs) in the nearby Virgo cluster. This sample is representative of the early-type population of galaxies in the absolute magnitude range -19.0 < Mr < -16.0. We analyze their absorption line-strength indices by means of index-index diagrams and scaling relations and use the stellar population ...
Şen, Ş. +16 more
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The origin of diverse α-element abundances in galaxy discs [PDF]
, 2018 Spectroscopic surveys of the Galaxy reveal that its disc stars exhibit a spread in [α/Fe] at fixed [Fe/H], manifest at some locations as a bimodality.
J. Mackereth +6 more
semanticscholar +1 more source
Chemie Ingenieur Technik, EarlyView., 2023 Let us consider an alternative perspective on climate change: The sum of solar radiation and heat generated by human activity result in a net energy input of 1.96 times that of the Sun on the Earth's surface. The expanding global population is expected to exacerbate this issue. Potential solutions are proposed, including replacement and heat recycling.
Martin Bertau, Gerald Steiner
wiley +1 more source
Abundance Ratios in Dwarf Elliptical Galaxies [PDF]
Proceedings of the International Astronomical Union, 2016 AbstractThe aim of this study is to determine abundance ratios and star formation histories (SFH) of dwarf ellipticals in the nearby Virgo cluster. We perform a stellar population analysis of 39 dEs and study them using index-index and scaling relations. We find an unusual behaviour where [Na/Fe] is under-abundant w.r.t.
Sen, Seyda +3 more
openaire +4 more sources