Results 71 to 80 of about 1,234,720 (380)
Ruthenium and hafnium abundances in giant and dwarf barium stars
, 2007 We present abundances for Ru and Hf, compare them to abundances of other heavy elements, and discuss the problems found in determining Ru and Hf abundances with laboratory gf-values in the spectra of barium stars.
Allen +31 more
core +1 more source
The solar wind heavy ion composition in the ascending phases of the solar cycles 23 and 25
Frontiers in Astronomy and Space SciencesThe approximately 11-year solar cycle has been shown to impact the heavy ion composition of the solar wind, even when accounting for streams of differing speeds; however, the heavy ion composition observed between the same specific phases of a past solar
D. T. Carpenter +8 more
doaj +1 more source
A SEARCH FOR STARS OF VERY LOW METAL ABUNDANCE. VI. DETAILED ABUNDANCES OF 313 METAL-POOR STARS [PDF]
, 2014 We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars.
I. Roederer +6 more
semanticscholar +1 more source
New calibrations for abundance determinations in HII regions [PDF]
, 2016 Simple relations for deriving the oxygen abundance in HII regions with intensities of the three strong emission lines R_2, R_3, and N_2 (R calibration) or S_2, R_3, and N_2 (S calibration) in their spectra are suggested.
Grebel, E. K., Pilyugin, L. S.
core +2 more sources
Chemical fingerprints of He-sdO stars
Open Astronomy, 2018 The chemical composition of helium-rich hot subluminous O stars plays an important role to understand and model their formation history. We present a spectroscopic analysis of four He-sdO stars,CD-31° 4800, [CW83] 0904- 02, LSS 1274 and LS IV +10° 9. The
Schindewolf Markus +5 more
doaj +1 more source
The Astrophysical Journal, 2023 Stellar streams in the Galactic halo are useful probes of the assembly of galaxies like the Milky Way. Many tidal stellar streams that have been found in recent years are accompanied by a known progenitor globular cluster or dwarf galaxy.
Keith Hawkins +10 more
doaj +1 more source
Barium abundances in Cepheids [PDF]
Monthly Notices of the Royal Astronomical Society, 2012 We derived the barium atmospheric abundances for a large sample of Cepheids, comprising 270 stars. The sample covers a large range of galactocentric distances, from about 4 to 15 kpc, so that it is appropriated to investigate the existence of radial barium abundance gradients in the galactic disc.
Jacques Raymond Daniel Lépine +6 more
openaire +4 more sources
Cosmological strangeness abundance
Physics Letters B, 2022 We investigate the strange particle composition of the early Universe in the hadron epoch $T_h\approx 150\ge T\ge 10$\,MeV. We study strangeness yield in thermal and chemical equilibrium constrained by prescribed entropy per baryon in a charge neutral and strangeness neutral $\langle s-\bar s\rangle$ Universe.
Cheng Tao Yang, Johann Rafelski
openaire +3 more sources
Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisited [PDF]
, 2017 Luminous Galactic OH/IR stars have been identified as massive (>4-5 M_s) AGB stars experiencing HBB and Li production. Their Rb abundances and [Rb/Zr] ratios derived from hydrostatic model atmospheres, are significantly higher than predictions from AGB ...
Garcia-Hernandez, D. A. +6 more
core +3 more sources
Effects of chronic browsing on life‐history traits of an irruptive large herbivore population
Population Ecology, EarlyView.This study aimed to determine the relationship between diet quality, body mass, and size (hind foot length), and female reproduction and sought to identify the mechanism by which high density under severe food limitations is maintained. Our results demonstrated that sika deer introduced to Nakanoshima Island have maintained high densities through high ...
Koichi Kaji +9 more
wiley +1 more source