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Related papers: Measuring Ages and Elemental Abundances from Unres…

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Spectroscopic studies of elliptical galaxies show that their stellar population ages, mean metallicity, and $\alpha$-enhancement traced by [Mg/Fe] all increase with galaxy stellar mass or velocity dispersion. We use one-zone galactic…

The abundance ratios [Y$/$Mg], [Y$/$Al], [Y$/$Si], [Y$/$Ca], and [Y$/$Ti] have been suggested as chemical clocks for solar-metallicity dwarf stars in the field as well as for giant stars in open clusters. To verify this last hypothesis, we…

Solar and Stellar Astrophysics · Physics 2022-08-30 Orlando J. Katime Santrich , Leandro Kerber , Yuri Abuchaim , Geraldo Gonçalves

We present a new library of semi-empirical stellar population models that are based on the empirical MILES and semi-empirical sMILES stellar libraries. The models span a large range of age and metallicity, in addition to an [$\alpha$/Fe]…

Astrophysics of Galaxies · Physics 2023-06-12 Adam T. Knowles , Anne E. Sansom , Alex Vazdekis , Carlos Allende Prieto

We present spatially resolved, simple stellar population equivalent ages, stellar metallicities, and abundance ratios for 456 massive ($10.3\lesssim\log(\mathrm{M}_*/\mathrm{M}_\odot)\lesssim11.8$) quiescent galaxies at $0.6\lesssim…

We present detailed chemical abundances in 8 clusters in the Large Magellanic Cloud (LMC). We measure abundances of 22 elements for clusters spanning a range in age of 0.05 to 12 Gyr, providing a comprehensive picture of the chemical…

Astrophysics of Galaxies · Physics 2015-06-03 J. E. Colucci , R. A. Bernstein , S. A. Cameron , A. McWilliam

Stellar elemental abundances are important for understanding the fundamental properties of a star or stellar group, such as age and evolutionary history, as well as the composition of an orbiting planet. However, as abundance measurement…

Previous studies have found that the elemental abundances of a star correlate directly with its age and metallicity. Using this knowledge, we derive ages for a sample of 250,000 stars taken from GALAH DR3 using only their overall…

In this study we present detailed calculations of absorption line indices on the Lick System based on the stellar models by Salasnich et al. (2000) calculated with enhanced mix of alpha-elements. Using the so-called Response Functions (RFs)…

Astrophysics · Physics 2009-11-07 R. Tantalo , C. Chiosi

The pixel-to-pixel spectral fitting technique is often used in studies of stellar populations. It enables the user to infer several parameters from integrated light spectra such as ages and chemical abundances. In this paper, we examine the…

Astrophysics of Galaxies · Physics 2020-10-14 Geraldo Gonçalves , Paula Coelho , Ricardo Schiavon , Christopher Usher

We present differential stellar population models, which allow improved determinations of the ages, iron and alpha-element abundances of old stellar populations from spectral fitting. These new models are calibrated at solar abundances…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 C. J. Walcher , P. Coelho , A. Gallazzi , S. Charlot

We measure the [${\alpha}$/Fe] abundances for 183 quiescent galaxies at z = 0.60 - 0.75 with stellar masses ranging 10.4 \leq log10 10.4 $\leq$ log10 (M$_*$ /M$_\odot$) $\leq$ 11.6 selected from the LEGA-C survey. We estimate…

A subset of 150 globular clusters in M87 has been selected on the basis of S/N ratio for abundance and age determinations from the sample of Paper I. Indices measuring the strength of the strongest spectral features were determined for the…

Astrophysics · Physics 2009-10-30 Judith G. Cohen , John P. Blakeslee , Anton Ryzhov

High-resolution, high-signal-to-noise (<S/N> = 85) spectra have been obtained for five stars -- CD-24:17504, CD-38:245, CS 22172-002, CS 22885-096, and CS 22949-037 -- having [Fe/H] < -3.5 according to previous lower S/N material. LTE…

Astrophysics · Physics 2009-11-06 John E. Norris , Sean G. Ryan , Timothy C. Beers

We present a novel statistical algorithm, Stellar Ages, which currently infers the age, metallicity, and extinction posterior distributions of stellar populations from their magnitudes. While this paper focuses on these parameters, the…

Solar and Stellar Astrophysics · Physics 2025-12-18 Joseph J. Guzman , Jeremiah W. Murphy , Andres F. Barrientos , Benjamin F. Williams , Julianne J. Dalcanton

We investigate the precision of the ages and metallicities of 21,000 mock simple stellar populations (SSPs) determined through full-spectrum fitting. The mock SSPs cover an age range of 6.8 $<$ log (age/yr) $<$ 10.2, for three wavelength…

Astrophysics of Galaxies · Physics 2020-09-09 Randa Asa'd , Paul Goudfrooij

We present new age and mass estimates for 920 stellar clusters in the Large Magellanic Cloud (LMC) based on previously published broad-band photometry and the stellar cluster analysis package, MASSCLEANage. Expressed in the generic fitting…

Astrophysics of Galaxies · Physics 2015-06-04 Bogdan Popescu , M. M. Hanson , Bruce G. Elmegreen

Recent work has shown that most globular clusters have at least two chemically distinct components, as well as cluster-to-cluster differences in the mean [O/Fe], [Mg/Fe], and [Si/Fe] ratios at similar [Fe/H] values. In order to investigate…

Solar and Stellar Astrophysics · Physics 2015-06-05 Don A. VandenBerg , Peter A. Bergbusch , Aaron Dotter , Jason W. Ferguson , Georges Michaud , Jacques Richer , Charles Proffitt

We present a spectroscopic analysis based on measurements of two mainly age-dependent spectrophotometric indices in the 4000A rest frame region, i.e. H+K(CaII) and Delta4000, for a sample of 15 early-type galaxies (ETGs) at 0.7 < z_{spec} <…

Astrophysics of Galaxies · Physics 2015-06-22 I. Lonoce , M. Longhetti , P. Saracco , A. Gargiulo , S. Tamburri

We present new stellar population models, $\alpha$-MC, self-consistently taking into account non-solar $\rm [\alpha/Fe]$ abundances for both isochrones and stellar spectra. The $\alpha$-MC models are based on $\alpha$-enhanced MIST…

Astrophysics of Galaxies · Physics 2024-10-30 Minjung Park , Charlie Conroy , Benjamin D. Johnson , Joel Leja , Aaron Dotter , Phillip A. Cargile

We investigate the Mg-sigma and <Fe>-sigma relations in a sample of 72 early-type galaxies drawn mostly from cluster and group environments using a homogeneous data-set which is well-calibrated onto the Lick/IDS system. The small intrinsic…