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Related papers: The GALAH Survey: Chemical Clocks

200 papers

Chemical clocks offer a powerful tool for estimating stellar ages from spectroscopic surveys. We present a new detailed spectroscopic analysis of 68 Kepler red giant stars to provide a suite of high-precision abundances along with…

Main sequence turn-off (MSTO) stars are good tracers of Galactic populations since their ages can be reliably estimated from atmospheric parameters. Based on the GALAH survey, we use the Yale Rotation Evolution Code to determine ages of…

Solar and Stellar Astrophysics · Physics 2022-04-27 Xunzhou Chen , Zhishuai Ge , Yuqin Chen , Shaolan Bi , Jie Yu , Wuming Yang , Jason W. Ferguson , Yaqian Wu , Yaguang Li

The GAIA space mission is impacting astronomy in many significant ways by providing a uniform, homogeneous and precise data set for over 1 billion stars and other celestial objects in the Milky Way and beyond. Exoplanet science has greatly…

Solar and Stellar Astrophysics · Physics 2023-08-16 C. Swastik , Ravinder K. Banyal , Mayank Narang , Athira Unni , Bihan Banerjee , P. Manoj , T. Sivarani

The stars of the Milky Way carry the chemical history of our Galaxy in their atmospheres as they journey through its vast expanse. Like barcodes, we can extract the chemical fingerprints of stars from high-resolution spectroscopy. The…

Star clusters are crucial for understanding how stars evolve. Their colour-magnitude diagrams show the effects of stellar evolution of approximately coeval objects with the same chemical composition. Furthermore, the determination of their…

Astrophysics of Galaxies · Physics 2025-04-03 F. A. Ferreira , J. F. C. Santos , W. J. B. Corradi , M. S. Angelo , F. F. S. Maia

We present estimates of stellar age and mass for 0.93 million Galactic disk main sequence turn-off and sub-giant stars from the LAMOST Galactic Spectroscopic Surveys. The ages and masses are determined by matching with stellar isochrones…

In the era of large stellar spectroscopic surveys, there is emphasis on deriving not only stellar abundances but also ages for millions of stars. In the context of Galactic archeology, stellar ages provide a direct probe of the formation…

Solar and Stellar Astrophysics · Physics 2017-05-23 Aaron Dotter , Charlie Conroy , Phillip Cargile , Martin Asplund

Stellar ages are key for determining the formation history of the Milky Way, but are difficult to measure precisely. Furthermore, methods that use chemical abundances to infer ages may entangle the intrinsic evolution of stars with the…

Astrophysics of Galaxies · Physics 2023-05-26 Jeff Shen , Joshua S. Speagle , J. Ted Mackereth , Yuan-Sen Ting , Jo Bovy

The GALAH survey targets one million stars in the southern hemisphere down to a limiting magnitude of V = 14 at the Anglo- Australian Telescope. The project aims to measure up to 30 elemental abundances and radial velocities (~1 km/s…

Astrophysics of Galaxies · Physics 2015-09-16 J. Bland-Hawthorn , S. Sharma , K. Freeman

Context. Stellar ages are typically very difficult to estimate for field stars. New empirical methods, based on abundance ratios of chemical elements, are emerging and need to be calibrated. Aims. Our main aim is to contribute to revealing…

We explore the structure of the element abundance--age--orbit distribution of the stars in the Milky Way's low-$\alpha$ disk, by (re-)deriving precise [Fe/H], [X/Fe] and ages, along with orbits, for red clump stars from the APOGEE survey.…

Solar and Stellar Astrophysics · Physics 2019-10-09 Melissa K. Ness , Kathryn V. Johnston , Kirsten Blancato , Hans-Walter Rix , Angus Beane , Jonathan C. Bird , Keith Hawkins

The technique of chemical tagging uses the elemental abundances of stellar atmospheres to `reconstruct' chemically homogeneous star clusters that have long since dispersed. The GALAH spectroscopic survey --which aims to observe one million…

The ability to measure precise and accurate stellar effective temperatures ($T_{\rm{eff}}$) and surface gravities ($\log(g)$) is essential in determining accurate and precise abundances of chemical elements in stars. Measuring $\log(g)$…

Varying oxygen abundance could impact the modeling-inferred ages. This work aims to estimate the ages of dwarfs considering observed oxygen abundance. To characterize 67,503 LAMOST and 4,006 GALAH FGK-type dwarf stars, we construct a grid…

We use the framework developed as part of the MESA Isochrones and Stellar Tracks (MIST) project to assess the utility of several types of observables in jointly measuring the age and 1D stellar model parameters in star clusters. We begin…

Solar and Stellar Astrophysics · Physics 2018-08-15 Jieun Choi , Charlie Conroy , Yuan-Sen Ting , Phillip A. Cargile , Aaron Dotter , Benjamin D. Johnson

We used the spectroscopic and astrometric data provided from the GALAH DR2 and Gaia DR2, respectively, for a large sample of stars to investigate the behaviour of the [$\alpha$/Fe] abundances via two procedures, i.e. kinematically and…

Astrophysics of Galaxies · Physics 2019-11-13 S. Karaali , S. Bilir , E. Yaz Gokce , O. Plevne

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…

The Milky Way was shaped by the mergers with several galaxies in the past. We search for remnant stars that were born in these foreign galaxies and assess their ages in an effort to put upper limits on the merger times and thereby better…

Observations of the Milky Way's low-$\alpha$ disk show that at fixed metallicity, [Fe/H], several element abundance, [X/Fe], correlate with age, with unique slopes and small scatters around the age-[X/Fe] relations. In this study, we turn…