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Related papers: Measuring Ages and Elemental Abundances from Unres…

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We present the results of determination of the age, helium mass fraction (Y), metallicity ([Fe/H]), and abundances of the elements C, N, O, Na, Mg, Ca, Ti, C and Mn for the Galactic globular cluster NGC 6652. We use its medium-resolution…

Astrophysics of Galaxies · Physics 2020-09-02 M. E. Sharina , V. V. Shimansky

Although the spectrum of a prototypical early-type galaxy is assumed to lack emission lines, a substantial fraction (likely as high as 30%) of nearby red sequence galaxy spectra contain emission lines with line ratios characteristic of low…

Astrophysics · Physics 2009-11-13 Genevieve J. Graves , Sandra M. Faber , Ricardo P. Schiavon , Renbin Yan

[ABRIDGED] The purpose of this work is to evaluate how several elements produced by different nucleosynthesis processes behave with stellar age and provide empirical relations to derive stellar ages from chemical abundances. We derive…

Spectra of galaxies contain an enormous amount of information about the relative mixture of ages and metallicities of constituent stars. We present a comprehensive study designed to extract the maximum information from spectra of data…

Astrophysics · Physics 2008-11-26 Marsha J. Wolf , Niv Drory , Karl Gebhardt , Gary J. Hill

We present results from modeling the optical spectra of a large sample of quiescent galaxies between 0.1 < z < 0.7 from the Sloan Digital Sky Survey (SDSS) and the AGN and Galaxy Evolution Survey (AGES). We examine how the stellar ages and…

In this work we present chemical abundances of heavy elements (Z$>$28) for a homogeneous sample of 1059 stars from HARPS planet search program. We also derive ages using parallaxes from Hipparcos and Gaia DR1 to compare the results. We…

Solar and Stellar Astrophysics · Physics 2018-06-13 E. Delgado Mena , M. Tsantaki , V. Zh. Adibekyan , S. G. Sousa , N. C. Santos , J. I. González Hernández , G. Israelian

We derive new spectral H_gamma index definitions which are robust age indicators for old and relatively old stellar populations and thus have great potential for solving the age-metallicity degeneracy of galaxy spectra. To study H_gamma as…

Astrophysics · Physics 2009-10-31 A. Vazdekis , N. Arimoto

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…

We have derived ages, metallicities and enhanced-element ratios [alpha/Fe] for a sample of 83 early-type galaxies essentially in groups, the field or isolated objects. The stellar population properties derived for each galaxy corresponds to…

We explore possible correlations between light profile shapes, as parameterized by the Sersic index or the concentration index C_re(1/3), and relevant stellar population parameters in early-type galaxies. Mean luminosity weighted ages,…

Astrophysics · Physics 2009-11-10 Alexandre Vazdekis , Ignacio Trujillo , Yoshihiko Yamada

Our understanding of early-type galaxies (ETGs) has grown in the past decade with the advance of full-spectrum fitting techniques used to infer the properties of the stellar populations that make-up the galaxy. We present ages, central…

Astrophysics of Galaxies · Physics 2024-06-25 Nicholas Barth , George C. Privon , Rana Ezzeddine , Aaron S. Evans , Ezequiel Treister

We investigate the stellar population properties of a sample of 24 massive quenched galaxies at $1.25<z_\mathrm{spec}<2.09$ identified in the COSMOS field with our Subaru/MOIRCS near-IR spectroscopic observations. Tracing the stellar…

Astrophysics of Galaxies · Physics 2015-07-01 M. Onodera , C. M. Carollo , A. Renzini , M. Cappellari , C. Mancini , N. Arimoto , E. Daddi , R. Gobat , V. Strazzullo , S. Tacchella , Y. Yamada

High resolution, high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < [Fe/H] < +0.1, and have been analysed in a parallel way to the work of Edvardsson et al. (1993).…

Astrophysics · Physics 2009-10-31 Y. Q. Chen , P. E. Nissen , G. Zhao , H. W. Zhang , T. Benoni

In this paper we study the underlying stellar population of a sample of 65 nearby early-type galaxies predominantly located in low density environments. Ages, metallicities and [alpha/Fe] ratios have been derived through the comparison of…

Astrophysics · Physics 2010-10-28 F. Annibali , A. Bressan , R. Rampazzo , W. W. Zeilinger , L. Danese

In this third paper of a series on the precision of obtaining ages of stellar populations using the full spectrum fitting technique, we examine the precision of this technique in deriving possible age spreads within a star cluster. We test…

Astrophysics of Galaxies · Physics 2021-05-12 Randa Asa'd , Paul Goudfrooij , A. M. As'ad , H. G. El-Mir , L. Begum , A. Aljasmi , O. Almatroushi

Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. Individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect…

Astrophysics of Galaxies · Physics 2022-02-09 Guy Worthey , Xiang Shi , Tathagata Pal , Hyun-chul Lee , Baitian Tang

An analysis of ages, metallicities, and [alpha/Fe] ratios of globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized in Puzia et al. (2004, Paper I of this series). In the light of…

We present an empirical model of age-dependent photospheric lithium depletion, calibrated using a large, homogeneously-analysed sample of 6200 stars in 52 open clusters, with ages from 2--6000 Myr and $-0.3<{\rm [Fe/H}]<0.2$, observed in…

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…

We present a Bayesian method to determine simultaneously the age, metallicity, distance modulus, and interstellar reddening by dust of any resolved stellar population, by comparing the observed and synthetic color magnitude diagrams on a…

Astrophysics of Galaxies · Physics 2019-05-08 V. H. Ramírez-Siordia , G. Bruzual , B. Cervantes Sodi , T. Bitsakis