Results 61 to 70 of about 876,778 (355)
Elemental Abundances in M31: Alpha and Iron Element Abundances from Low-Resolution Resolved Stellar Spectroscopy in the Stellar Halo [PDF]
, 2019 Measurements of [Fe/H] and [$\alpha$/Fe] can probe the minor merging history of a galaxy, providing a direct way to test the hierarchical assembly paradigm.
Cunningham, Emily C. +4 more
core +3 more sources
ASPCAP: THE APOGEE STELLAR PARAMETER AND CHEMICAL ABUNDANCES PIPELINE [PDF]
, 2015 The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has built the largest moderately high-resolution (R ≈ 22,500) spectroscopic map of the stars across the Milky Way, and including dust-obscured areas.
A. G. García Pérez +29 more
semanticscholar +1 more source
The Abundance of Helium in Stellar Interiors [PDF]
Highlights of Astronomy, 1971 From the titles of the other contributions to this morning’s session, one deduces that the hard facts of theory are to be sandwiched between the loose speculations of direct observation. I shall therefore feel free to discuss theoretical implications from stellar structure unencumbered by what are, after all, but peripheral considerations.I should ...
openaire +2 more sources
Multiple Populations in Star Clusters
Universe, 2022 We review the multiple population (MP) phenomenon of globular clusters (GCs): i.e., the evidence that GCs typically host groups of stars with different elemental abundances and/or distinct sequences in photometric diagrams.
Antonino P. Milone, Anna F. Marino
doaj +1 more source
Non-local Thermodynamic Equilibrium Stellar Spectroscopy with 1D and Models. I. Methods and Application to Magnesium Abundances in Standard Stars [PDF]
, 2016 We determine Mg abundances in six Gaia benchmark stars using theoretical one-dimensional (1D) hydrostatic model atmospheres, as well as temporally and spatially averaged three-dimensional ( ) model atmospheres.
M. Bergemann +5 more
semanticscholar +1 more source
Limitations of Stellar Abundance Determinations [PDF]
Symposium - International Astronomical Union, 1991 The information content of (photospheric) stellar spectra and the accuracy of abundance determinations are discussed. Besides the physical properties of the line spectra, the spectral resolution, the signal-to-noise ratio, but also the incompleteness of the knowledge of the contributing blends limit the abundance information.
openaire +2 more sources
ABUNDANCES, STELLAR PARAMETERS, AND SPECTRA FROM THE SDSS-III/APOGEE SURVEY [PDF]
, 2015 The SDSS-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey operated from 2011–2014 using the APOGEE spectrograph, which collects high-resolution (R ∼ 22,500), near-IR (1.51–1.70 μm) spectra with a multiplexing (300 fiber-fed ...
J. Holtzman +42 more
semanticscholar +1 more source
Stellar evolution with SMC chemical abundances [PDF]
International Astronomical Union Colloquium, 1981 Evolutionary computations are presented for massive stars between 20 Mo and 100 Mo with chemical abundances holding for the Small Magellanic Cloud, i.e. X = .76 and Z = .003. Mass loss by stellar wind is taken into account during core hydrogen burning.
D. Vanbeveren, P. Hellings
openaire +2 more sources
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
openaire +2 more sources
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