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We use integrated-light spectroscopic observations to measure metallicities and chemical abundances for two extragalactic young massive star clusters (NGC1313-379 and NGC1705-1). The spectra were obtained with the X-Shooter spectrograph on…

Astrophysics of Galaxies · Physics 2017-07-19 Svea Hernandez , Søren Larsen , Scott Trager , Paul Groot

ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…

Astrophysics of Galaxies · Physics 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

We present a new method to determine the star formation and metal enrichment histories of any resolved stellar system. This method is based on the fact that any observed star in a colour-magnitude diagram will have a certain probability of…

Astrophysics of Galaxies · Physics 2015-06-11 Emma E. Small , David Bersier , Maurizio Salaris

It is well established that the chemical structure of the Milky Way exhibits a bimodality with respect to the $\alpha$-enhancement of stars at a given [Fe/H]. This has been studied largely based on a bulk $\alpha$ abundance, computed as a…

Astrophysics of Galaxies · Physics 2019-09-20 Kirsten Blancato , Melissa Ness , Kathryn V. Johnston , Jan Rybizki , Megan Bedell

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

Galactic bulges are central to understanding galaxy formation and evolution. Here we report on recent studies using micro-lensing events to obtain spectra of high resolution and moderately high signal-to-noise ratios of dwarf stars in the…

Stellar population studies of massive early-type galaxies (ETGs) suggest that the stellar initial mass function may not be universal. In particular, the centres of ETGs seem to contain an excess of low-mass dwarf stars compared to our own…

Astrophysics of Galaxies · Physics 2024-02-12 Taniya Parikh , Roberto Saglia , Jens Thomas , Kianusch Mehrgan , Ralf Bender , Claudia Maraston

Star clusters are fundamental building blocks of galaxies. Their formation is related to the density and pressure in progenitor molecular clouds and their environmental conditions. To understand better the dynamical processes driving star…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-11 M. E. Sharina , T. H. Puzia , R. Chandar , P. Goudfroij , E. Davoust

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 a new version of the compiled catalogue of nearby stars for which was published the spectoscopically determined effective temperatures, surface gravities, and abundances of iron, magnesium, calcium, silicon, and titanium.…

Astrophysics · Physics 2007-10-25 T. V. Borkova , M. S. Katchieva , B. A. Marsakov , D. M. Pitkina

There has been an incredibly large investment in obtaining high-resolution stellar spectra for determining chemical abundances of stars. This information is crucial to answer fundamental questions in Astronomy by constraining the formation…

Solar and Stellar Astrophysics · Physics 2019-09-11 Paula Jofré , Ulrike Heiter , Caroline Soubiran

A catalog compiling the parameters of 346 open clusters, including their metallicities, positions, ages, and velocities has been composed. The elements of the Galactic orbits for 272 of the clusters have been calculated. Spectroscopic…

Astrophysics of Galaxies · Physics 2016-02-17 V. A. Marsakov , M. L. Gozha , V. V. Koval' , L. V. Shpigel'

We present unified chemical and spectrophotometric evolutionary synthesis models that allow to describe composite stellar populations in a chemically consistent way. Keeping track of the ISM abundance at birth of each star and using sets of…

Astrophysics · Physics 2020-05-27 U. Fritze-v. Alvensleben

Elemental abundance ratios as tracers of stellar populations are discussed with emphasis on F, G, and K stars providing a `fossil' record of the chemical evolution of the Galaxy. Most abundance studies have been based on homogeneous 1D…

Astrophysics of Galaxies · Physics 2011-09-20 Poul Erik Nissen

We define a method for analysis of the integrated spectra of extra-galactic globular clusters that provides more reliable measures of age, metallicity and alpha-element abundance ratio than have so far been achieved. The method involves the…

Astrophysics · Physics 2009-11-10 Robert N. Proctor , Duncan A. Forbes , Michael A. Beasley

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

We use the first release of the SDSS/MaStar stellar library comprising ~9000, high S/N spectra, to calculate integrated spectra of stellar population models. The models extend over the wavelength range 0.36-1.03 micron and share the same…

The determination of chemical abundances from stellar spectra is considered a mature field of astrophysics. Digital spectra of stars are recorded and processed with standard techniques, much like samples in the biological sciences.…

Astrophysics · Physics 2007-05-23 C. Allende Prieto

Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features--spectral indices--whose strengths rely on the abundances of one or more elements. Such comparisons hinge…

Astrophysics · Physics 2009-06-23 A. Dotter , B. Chaboyer , J. W. Ferguson , H. -c. Lee , G. Worthey , E. Baron , D. Jevremovic

HARPS spectra with signal-to-noise ratios S/N > 600 at 6000 A were analysed with MARCS model atmospheres to obtain 1D LTE abundances of C, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Sr, and Y for 72 nearby solar-type stars with metallicities in…

Solar and Stellar Astrophysics · Physics 2020-08-19 P. E. Nissen , J. Christensen-Dalsgaard , J. R. Mosumgaard , V. Silva Aguirre , E. Spitoni , K. Verma.
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