Results 11 to 20 of about 261,878 (239)

Dust Formation in a Galaxy with Primitive Abundances [PDF]

open access: yesScience, 2009
Interstellar dust plays a crucial role in the evolution of galaxies. It governs the chemistry and physics of the interstellar medium. In the local universe, dust forms primarily in the ejecta from stars, but its composition and origin in galaxies at very early times remain controversial.
Sloan, G C   +8 more
openaire   +5 more sources

Differences in the Gastric Microbiotas of Neighboring Populations With Divergent Risks of Gastric Cancer. [PDF]

open access: yesJ Gastroenterol Hepatol
ABSTRACT Background Although Helicobacter pylori plays a central role in gastric cancer (GC), other microorganisms involved in gastric dysbiosis may also impact carcinogenesis. We aimed to characterize gastric dysbiosis and its role in the transition from non‐atrophic gastritis (NAG) to gastric premalignant lesions (GPLs) in two populations from Nariño,
Caguazango JC   +6 more
europepmc   +2 more sources

Chemical abundances in active galaxies [PDF]

open access: yesMonthly 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.
openaire   +2 more sources

Abundance of field galaxies [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2015
15 pages, 13 figures.
Klypin, Anatoly   +3 more
openaire   +2 more sources

The Metallicity and Distance of Leo A from Blue Supergiants

open access: yesThe 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

The evolution of the oxygen abundance in the Galaxy [PDF]

open access: yesNew Astronomy Reviews, 2001
AbstractWe discuss the evolution of the [O/Fe] as a function of [Fe/H] in the Galaxy. In particular, we discuss the influence of different stellar yields as well as different SN (II, I) rates on the [O/Fe] ratio. Possible explanations for the steep rise of the [O/Fe] ratio at low metallicities, as indicated by recent observations, are critically ...
MATTEUCCI, MARIA FRANCESCA, CHIAPPINI C.
openaire   +3 more sources

Chemical abundances in Seyfert galaxies – VIII. Argon abundance estimates [PDF]

open access: yesMonthly 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 ...
A F Monteiro, O L Dors
openaire   +4 more sources

Robust Data-driven Metallicities for 175 Million Stars from Gaia XP Spectra

open access: yesThe 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

The Galaxy platform for accessible, reproducible and collaborative biomedical analyses: 2022 update. [PDF]

open access: yes, 2022
Galaxy is a mature, browser accessible workbench for scientific computing. It enables scientists to share, analyze and visualize their own data, with minimal technical impediments.
Galaxy Community,
core   +1 more source

Understanding the Chemical Evolution of Blue Edge-on Low Surface Brightness Galaxies

open access: yesThe 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

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