English
Related papers

Related papers: An Intermediate-age Alpha-rich Galactic Population…

200 papers

We measure chemical abundance ratios and radial velocities in four massive (i.e., young) [alpha/Fe]-rich red giant stars using high-resolution high-S/N spectra from ESPaDOnS fed by Gemini-GRACES. Our differential analysis ensures that our…

We study how the predicted [$\alpha$/Fe]-[Fe/H] relations in early-type galaxies vary as functions of their stellar masses, ages and stellar velocity dispersions, by making use of cosmological chemodynamical simulations with feedback from…

Astrophysics of Galaxies · Physics 2018-08-01 Fiorenzo Vincenzo , Chiaki Kobayashi , Philip Taylor

Oxygen and carbon are important elements in stellar populations. Their behavior refers to the formation history of the stellar populations. C and O abundances would also obviously influence stellar opacities and the overall metal abundance…

Solar and Stellar Astrophysics · Physics 2016-12-21 Z. S. Ge , S. L. Bi , Y. Q. Chen , T. D. Li , J. K. Zhao , K. Liu , Fergusion J. W. , Y. Q. Wu

We study the relationship between age, metallicity, and alpha-enhancement of FGK stars in the Galactic disk. The results are based upon the analysis of high-resolution UVES spectra from the Gaia-ESO large stellar survey. We explore the…

Observations of the stellar content of the Milky Way's bulge helps to understand the stellar content and evolution of distant galaxies. In this brief overview I will first highlight some recent work directed towards measuring the history of…

Astrophysics · Physics 2007-05-23 Jay A. Frogel

Trends in the enrichment of elements with stellar ages are a powerful avenue to identify unexplained origins of the elements. We investigate the stellar abundance trends of low to intermediate-mass stars using the GALAH DR3 high-resolution…

Astrophysics of Galaxies · Physics 2024-10-15 Evans K. Owusu , Sven Buder , Ashley J. Ruiter , Ivo R. Seitenzahl , Nicolás Rodríguez-Segovia

We exploit the [Mg/Mn]-[Al/Fe] chemical abundance plane to help identify nearby halo stars in the 14th data release from the APOGEE survey that have been accreted on to the Milky Way. Applying a Gaussian Mixture Model, we find a `blob' of…

Astrophysics of Galaxies · Physics 2020-02-12 Payel Das , Keith Hawkins , Paula Jofre

Chemical abundances are an essential tool in untangling the Milky Way's enrichment history. However, the evolution of the interstellar medium abundance gradient with cosmic time is lost as a result of radial mixing processes. For the first…

Robust age estimates of red giant stars are now possible thanks to the precise inference of their mass based on asteroseismic constraints. However, there are cases where such age estimates can be highly precise yet very inaccurate. An…

We have determined detailed elemental abundances and stellar ages for a sample of now 38 microlensed dwarf and subgiant stars in the Galactic bulge. Stars with sub-solar metallicities are all old and have enhanced alpha-element abundances…

Astrophysics of Galaxies · Physics 2012-01-11 T. Bensby , S. Feltzing , A. Gould , J. A. Johnson , M. Asplund , D. Adén , J. Meléndez , J. G. Cohen , I. Thompson , S. Lucatello , A. Gal-Yam

We report the abundances of C, Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Sm in 25 solar-type stars in the solar neighbourhood, and their correlations with ages, kinematics, and orbital parameters. The…

Solar and Stellar Astrophysics · Physics 2015-06-04 R. da Silva , G. F. Porto de Mello , A. C. Milone , L. da Silva , L. S. Ribeiro , H. J. Rocha-Pinto

In this paper we investigate how the chemical and kinematic properties of stars vary as a function of age. Using data from a variety of photometric, astrometric and spectroscopic surveys, we calculate the ages, phase space information and…

Astrophysics of Galaxies · Physics 2018-06-27 John J. Vickers , Martin C. Smith

One of the fundamental questions in astronomy is how planetary systems form and evolve. Measuring the planetary occurrence and architecture as a function of time directly addresses this question. In the fourth paper of the Planets Across…

Earth and Planetary Astrophysics · Physics 2023-11-01 Jia-Yi Yang , Di-Chang Chen , Ji-Wei Xie , Ji-Lin Zhou , Subo Dong , Zi Zhu , Zheng Zheng , Chao Liu , Weikai Zong , Ali Luo

We analysed the chemodynamical evolution of the Galactic disc using precise [Mg/Fe] abundances from a previous study and accurate Gaia data. For this purpose, we estimated ages and dynamical properties for 366 MSTO solar neighbourhood stars…

We present a detailed elemental abundance study of 90 F and G dwarf, turn-off and subgiant stars in the Galactic bulge. Based on high-resolution spectra acquired during gravitational microlensing events, stellar ages and abundances for 11…

We investigated the theoretical biases affecting the asteroseismic grid-based estimates of stellar parameters in the presence of a mismatch between the heavy element mixture of observed stars and stellar models. We performed a controlled…

Solar and Stellar Astrophysics · Physics 2024-03-06 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti

Galactic archaeology relies on accurate stellar parameters to reconstruct the galaxy's history, including information on stellar ages. While the precision of data has improved significantly in recent years, stellar models used for age…

Solar and Stellar Astrophysics · Physics 2025-04-25 Leslie M. Morales , Jamie Tayar , Zachary R. Claytor

We present phosphorus abundance measurements for a total of 102 giant stars, including 82 stars in 24 open clusters and 20 Cepheids, based on high-resolution near-infrared spectra obtained with GIANO-B. Evolution of phosphorus abundance,…

Red giants undergo the first dredge-up, a mixing event that creates a connection between their surface [C/N] and their mass and age. We derive a [C/N]-Age relationship for red giants calibrated on APOGEE DR17 abundances and APOKASC-3…

Solar and Stellar Astrophysics · Physics 2025-10-01 John D. Roberts , Marc H. Pinsonneault , Jennifer A. Johnson , Liam O. Dubay , James W. Johnson