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Related papers: Abundance ratios in GALAH DR2 and their implicatio…

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In massive stars (initial mass of > 9 solar masses), the weak s (slow neutron capture) process produces elements between Fe and Zr, enriching the Galaxy with these elements through core-collapse supernova explosions. The weak s-process…

Solar and Stellar Astrophysics · Physics 2025-12-01 Emma Kotar , Shuya Ota , Allyson Dewey , Joshua Millman , Lorenzo Roberti , Marco Pignatari

We summarize a selection process to identify red giants in the direction of the southern warp of the Galactic disk, employing VI_C photometry and multi-object spectroscopy. We also present results from follow-up high-resolution, high-S/N…

Astrophysics · Physics 2008-11-26 Bruce W. Carney , David Yong , Luisa de Almeida , Patrick Seitzer

We use abundances of Ca, O, Na, Al from high resolution UVES spectra of 200 red giants in 17 globular clusters (GCs) to investigate the correlation found by Lee et al. (2009) between chemical enrichment from SN II and star-to-star…

Metal-poor stars are key for studying the formation and evolution of the Galaxy. Evidence of the early mergers that built up the Galaxy remains in the distributions of abundances, kinematics, and orbital parameters of its stars. Several…

Astrophysics of Galaxies · Physics 2023-09-06 André Rodrigo da Silva , Rodolfo Smiljanic

Previous work on the abundances of C, O, Na, Mg, Si, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn in low-alpha (accreted) and high-alpha (in situ born) halo stars is extended to include the abundances of Sc, V, and Co, enabling us to study the…

Astrophysics of Galaxies · Physics 2023-12-14 P. E. Nissen , A. M. Amarsi , Á. Skúladóttir , W. J. Schuster

We present chemical abundance analyses of sodium, iron-peak and neutron-capture elements for 97 kinematically selected thick disk, inner halo and outer halo stars with metallicities -3.3<[Fe/H]<-0.5. The main aim of this study is to examine…

Astrophysics of Galaxies · Physics 2015-06-16 Miho N. Ishigaki , Wako Aoki , Masashi Chiba

Using recently calculated yields for Type II supernovae, along with models for chemical evolution and the distribution of mass in the interstellar medium, the current abundances and spatial distributions of two key gamma-ray…

Astrophysics · Physics 2009-10-28 F. X. Timmes , S. E. Woosley , D. H. Hartmann , R. D. Hoffman , T. A. Weaver , F. Matteucci

A large population of intermediate-separation binaries, consisting of a main-sequence (MS) star and a white dwarf (WD), has recently emerged from Gaia's third data release (DR3), posing challenges to current models of binary evolution. Here…

Solar and Stellar Astrophysics · Physics 2024-10-02 Param Rekhi , Sagi Ben-Ami , Na'ama Hallakoun , Sahar Shahaf , Silvia Toonen , Hans-Walter Rix

The Milky Way bulge is an important tracer of the early formation and chemical enrichment of the Galaxy. The abundances of different iron-peak elements in field bulge stars can give information on the nucleosynthesis processes that took…

Solar and Stellar Astrophysics · Physics 2020-08-19 H. Ernandes , B. Barbuy , A. Friaça , V. Hill , M. Zoccali , D. Minniti , A. Renzini , S. Ortolani

The GALAH survey is a large high-resolution spectroscopic survey using the newly commissioned HERMES spectrograph on the Anglo-Australian Telescope. The HERMES spectrograph provides high-resolution (R ~28,000) spectra in four passbands for…

The atmospheric parameters and abundances of Mg, Si, Ca, and Ti have been determined for 20 stars using the Gaia DR2 parallaxes, high-resolution spectra, and the non-local thermodynamic equilibrium (non-LTE) line formation modeling. A…

Solar and Stellar Astrophysics · Physics 2019-09-04 Lyudmila Mashonkina , Maria Neretina , Tatyana Sitnova , Yuri Pakhomov

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

We measure chemical abundances for over 20 elements of 15 N-rich field stars with high resolution ($R \sim 30000$) optical spectra. We find that Na, Mg, Al, Si, and Ca abundances of our N-rich field stars are mostly consistent with those of…

Astrophysics of Galaxies · Physics 2021-06-02 Jincheng Yu , Baitian Tang , J. G. Fernandez-Trincado , Douglas Geisler , Hongliang Yan , M. Soto

The chemical abundance patterns of near-pristine objects provide important constraints on the properties of the first generations of stars in the Universe. We present the chemical abundances of five very metal-poor ([M/H]<-2.5) sub damped…

We analyse the abundance ratios of the light elements Mg, Ca, C and N, relative to Fe, for 147 red-sequence galaxies in the Coma cluster and the Shapley Supercluster. The sample covers a six-magnitude range in luminosity, from giant…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Russell J. Smith , John R. Lucey , Michael J. Hudson , Terry J. Bridges

We explore the effects on nucleosynthesis in Type II supernovae of various parameters (mass cut, neutron excess, explosion energy, progenitor mass) in order to explain the observed trends of the iron-peak element abundance ratios ([Cr/Fe],…

The stellar populations of galaxies hold vital clues to their formation histories. In this paper we present results based on modeling stacked spectra of early-type galaxies drawn from the Sloan Digital Sky Survey (SDSS) as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Charlie Conroy , Genevieve Graves , Pieter van Dokkum

Binary stellar systems form a large fraction of the Galaxy's stars. They are useful as laboratories for studying the physical processes taking place within stars, and must be correctly taken into account when observations of stars are used…

To reach a deeper understanding of the origin of elements in the periodic table, we construct Galactic chemical evolution (GCE) models for all stable elements from C (A=12) to U (A=238) from first principles, i.e., using theoretical…

Astrophysics of Galaxies · Physics 2020-08-12 Chiaki Kobayashi , Amanda I. Karakas , Maria Lugaro

Stellar abundances and ages afford the means to link chemical enrichment to galactic formation. In the Milky Way, individual element abundances show tight correlations with age, which vary in slope across ([Fe/H]-[$\alpha$/Fe]). Here, we…