Results 11 to 20 of about 948,048 (332)
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
The evolution of the oxygen abundance in the Galaxy [PDF]
New 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 +2 more sources
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
openaire +4 more sources
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
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
Diagnostic Accuracy of Shotgun Metagenomics for Bloodstream Infections Is Influenced by Bioinformatics Workflow Selection. [PDF]
MicrobiologyopenOur work shows that the selection of bioinformatics pipelines for diagnosing bloodstream infection strongly affects the precision of the findings, and an optimized BLAST pipeline was superior to the alternatives, as it was the only method that accurately identified the causative pathogens.
Song Y +5 more
europepmc +2 more sources
Chemical Abundances of New Member Stars in the Tucana II Dwarf Galaxy [PDF]
, 2018 We present chemical abundance measurements for seven stars with metallicities ranging from Fe/H] = −3.3 to [Fe/H] = −2.4 in the Tucana II ultra-faint dwarf galaxy (UFD), based on high-resolution spectra obtained with the MIKE spectrograph on the 6.5 m ...
A. Chiti +5 more
semanticscholar +1 more source
DETAILED CHEMICAL ABUNDANCES IN THE r-PROCESS-RICH ULTRA-FAINT DWARF GALAXY RETICULUM 2 [PDF]
, 2016 The ultra-faint dwarf (UFD) galaxy Reticulum 2 (Ret 2) was recently discovered in images obtained by the Dark Energy Survey. We have observed the four brightest red giants in Ret 2 at high spectral resolution using the Michigan/Magellan Fiber System.
I. Roederer +12 more
semanticscholar +1 more source