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We present radial velocities and chemical abundance ratios of [Fe/H], [O/Fe], [Si/Fe], and [Ca/Fe] for 264 red giant branch (RGB) stars in three Galactic bulge off-axis fields located near (l,b)=(-5.5,-7), (-4,-9), and (+8.5,+9). The…

We derive stellar population parameters and radial gradients within 0.65 $R_e$ for spatially resolved spectra of 2968 early-type galaxies from MaNGA, spanning stellar velocity dispersions ($\sigma$) of 50--340 km s$^{-1}$. Light-weighted…

星系天体物理 · 物理学 2025-11-04 Tathagata Pal , Guy Worthey

Among stars in Galactic globular clusters the carbon abundance tends to decrease with increasing luminosity on the upper red giant branch, particularly within the lowest metallicity clusters. While such a phenomena is not predicted by…

太阳与恒星天体物理 · 物理学 2019-04-08 Jeffrey M. Gerber , Michael M. Briley , Graeme H. Smith

Recent observations have revealed a population of $\alpha$-element abundances enhanced giant stars with unexpected high masses ($\gtrsim$1 $M_\odot$) from asteroseismic analysis and spectroscopy. Assuming single-star evolution, their masses…

Recent spectroscopic explorations of large Galactic stellar samples stars have revealed the existence of red giants with [$\alpha$/Fe] ratios that are anomalously high, given their relatively young ages. We revisit the GALAH DR3 survey to…

太阳与恒星天体物理 · 物理学 2022-12-21 S. Borisov , N. Prantzos , C. Charbonnel

We analyze existing measurements of [Fe/H] and [$\alpha$/Fe] for individual red giant branch (RGB) stars in the Giant Stellar Stream (GSS) of M31 to determine whether spatial abundance gradients are present. These measurements were obtained…

星系天体物理 · 物理学 2021-07-14 Ivanna Escala , Karoline M. Gilbert , Jennifer Wojno , Evan N. Kirby , Puragra Guhathakurta

Our aim is to measure accurate, homogeneous neutron-capture element abundances for the sample of 32 EMP giant stars studied earlier in this series, including 22 stars with [Fe/H] $< -$3.0. Based on high-resolution, high S/N spectra from the…

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

Detailed chemical analyses of M dwarfs are scarce but necessary to constrain the formation environment and internal structure of planets being found around them. We present elemental abundances of 13 M dwarfs (2900 < Teff < 3500 K) observed…

This paper reports on the spectroscopic investigation of 101 Cepheids in the Carina region. These Cepheids extend previous samples by about 35% in number and increase the amount of the galactic disk coverage especially in the direction of l…

星系天体物理 · 物理学 2015-05-28 R. E. Luck , S. M. Andrievsky , V. V. Kovtyukh , W. Gieren , D. Graczyk

We present a detailed analysis of 26 barium stars, including dwarf barium stars, providing their atmospheric parameters (Teff, log g, [Fe/H], vt) and elemental abundances. We aim at deriving gravities and luminosity classes of the sample…

天体物理学 · 物理学 2009-11-11 Dinah M. Allen , Beatriz Barbuy

The chemical composition of multiple populations in the massive globular cluster (GC) NGC~2808 is addressed with the homogeneous abundance re-analysis of 140 red giant branch (RGB) stars. UVES spectra for 31 stars and GIRAFFE spectra for…

太阳与恒星天体物理 · 物理学 2015-09-23 Eugenio Carretta

We measured [Fe/H] and [$\alpha$/Fe] using spectral synthesis of low-resolution stellar spectroscopy for 70 individual red giant branch stars across four fields spanning the outer disk, Giant Stellar Stream (GSS), and inner halo of M31.…

We measure abundances of 12 elements (Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni) in a sample of 86 metal-poor ($-2 \lesssim \text{[Fe/H]} \lesssim -1$) subgiant stars in the solar neighborhood. Abundances are derived from…

We measured $^{35}$Cl abundances in 52 M giants with metallicities between -0.5 $<$ [Fe/H] $<$ 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the IRTF and from optical echelle spectra. We…

太阳与恒星天体物理 · 物理学 2021-03-16 Z. G. Maas , C. A. Pilachowski

Carbon-enhanced metal-poor (CEMP) stars bear important imprints of the early chemical enrichment of any stellar system. While these stars are known to exist in copious amounts in the Milky Way halo, detailed chemical abundance data from the…

太阳与恒星天体物理 · 物理学 2017-10-25 A. Susmitha , A. Koch , T. Sivarani

We have obtained [Mg/Fe] measurements for 76.3% of the stars in the MILES spectral library used for understanding stellar atmospheres and stellar populations in galaxies and star clusters. These abundance ratios were obtained through (1) a…

太阳与恒星天体物理 · 物理学 2015-05-27 Andre de Castro Milone , Anne E. Sansom , Patricia Sanchez-Blazquez

M dwarfs are prominent targets of planet search projects, and their chemical composition is crucial to understanding the formation process or interior of orbiting exoplanets. However, measurements of elemental abundances of M dwarfs have…

Elemental abundances hold important information about the star formation history in the Galactic Center. The thermal X-ray spectra of certain stars can provide a robust probe of elemental abundances, mainly through the presence of K-shell…

星系天体物理 · 物理学 2026-05-01 Ziqian Hua , Zhiyuan Li

We present the iron abundance and abundance ratios for 18 elements with respect to Fe in a sample of stars with a wide range in luminosity from luminous giants to stars near the turnoff in the globular cluster M5. The analyzed spectra,…

天体物理学 · 物理学 2009-11-07 Solange V. Ramirez , Judith G. Cohen