Results 31 to 40 of about 226,407 (198)
Chemical abundances of LINER galaxies – nitrogen abundance estimations
Monthly Notices of the Royal Astronomical SocietyABSTRACT In this work, we investigated the nitrogen and oxygen abundances in a sample of galaxies with Low Ionization Nuclear Emission Regions (LINERs) in their nucleus. Optical spectroscopic data (3600 – 10 000 Å) of 40 LINERs from the Mapping Nearby Galaxies (MaNGAs) survey were considered.
C B Oliveira +7 more
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Chemical Abundances of a Sample of Oxygen-dominated Galaxies
The Astrophysical Journal, 2023 We spectroscopically analyzed a sample of 85 Sloan Digital Sky Survey compact, oxygen-dominated galaxies located at redshift z ∼ 0.001–0.350, selected because of their large equivalent width of [O iii ] λ 5007 (larger than 200 Å). These galaxies might be
B. E. Miranda-Pérez +1 more
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The Astrophysical JournalVery metal-poor (VMP) stars provide a record of the chemical composition and dynamics of the early Galaxy. Based on the high-resolution and high signal-to-noise ratio spectra from the Subaru Telescope for 103 VMP stars, in this series of papers we ...
Jianrong Shi +12 more
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Planetary nebulae in the inner Milky Way: new abundances [PDF]
, 2009 The study of planetary nebulae in the inner-disk and bulge gives important information on the chemical abundances of elements such as He, N, O, Ar, Ne, and on the evolution of these abundances, which is associated with the evolution of intermediate-mass ...
Cavichia, O. +2 more
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On the Galactic chemical evolution of sulphur. Sulphur abundances from the [S i] 1082 nm line in giants [PDF]
, 2013 Context. The Galactic chemical evolution of sulphur is still under debate. At low metallicities some studies find no correlation between [S/Fe] and [Fe/H], others find [S/Fe] increasing towards lower metallicities, and still others find a combination of ...
Dupree, A. K., Matrozis, E., Ryde, N.
core +1 more source
Evidence for Ubiquitous Carbon Grain Destruction in Hot Protostellar Envelopes
The Astrophysical Journal Letters, 2023 Earth is deficient in carbon and nitrogen by up to ∼4 orders of magnitude compared with the Sun. Destruction of (carbon- and nitrogen-rich) refractory organics in the high-temperature planet-forming regions could explain this deficiency.
Pooneh Nazari +4 more
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Chemical abundances of the Typhon stellar stream
Monthly Notices of the Royal Astronomical Society, 2022 ABSTRACT We present the first high-resolution chemical abundances of seven stars in the recently discovered high-energy stream Typhon. Typhon stars have apocentres r ≳ 100 kpc, making this the first detailed chemical picture of the Milky Way’s very distant stellar halo.
Alexander P Ji +4 more
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The Astronomical JournalIn this study, we investigate interstellar absorption lines along the line of sight toward the galactic low-mass X-ray binary Cygnus X-2. We combine absorption line data obtained from high-resolution X-ray spectra collected with the Chandra and XMM ...
I. Psaradaki +12 more
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PArthENoPE: Public Algorithm Evaluating the Nucleosynthesis of Primordial Elements [PDF]
, 2007 We describe a program for computing the abundances of light elements produced during Big Bang Nucleosynthesis which is publicly available at http://parthenope.na.infn.it/.
A. Cirillo +51 more
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High-precision chemical abundances of Galactic building blocks
Astronomy & Astrophysics, 2022 Context. Sequoia is a retrograde kinematic substructure in the nearby Galactic halo, whose properties are a matter of debate. For example, previous studies do not necessarily agree on the chemical abundances of Sequoia stars, which are important for understanding its nature. Aims.
Matsuno, Tadafumi +7 more
openaire +3 more sources