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Related papers: Individual element sensitivity for stellar evoluti…

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We investigate stellar elemental abundance patterns at z = 0 in 8 low-mass (M_* = 10^6 - 10^9 M_sun) galaxies in the Feedback in Realistic Environments (FIRE-2) cosmological simulations. Using magnesium (Mg) as a representative…

Estimates of the gas temperature in planetary nebulae obtained from the [O III] emission line ratio and from the Balmer discontinuity indicate differences reaching up to 6000 K (Liu and Danziger 1993). The [O III] temperature is commonly…

Astrophysics · Physics 2007-05-23 Lucimara P. Martins , Sueli M. M. Viegas

Our unified chemical and spectrophotometric evolution code allows to simultaneously study the ISM abundances of a series of elements and the spectral properties of the stellar population in our model galaxies. We use stellar evolutionary…

Astrophysics · Physics 2007-05-23 Uta Fritze - v. Alvensleben

Theoretical physical-chemical models for the formation of planetary systems depend on data quality for the Sun's composition, that of stars in the solar neighbourhood, and of the estimated "pristine" compositions for stellar systems. The…

The stars of the middle main sequence have relatively quiescent outer layers, and unusual chemical abundance patterns may develop in their atmospheres. The presence of chemical peculiarities reveal the action of such subsurface phenomena as…

Solar and Stellar Astrophysics · Physics 2015-06-18 J. D. Bailey , J. D. Landstreet , S. Bagnulo

We present results of model atmosphere/line formation calculations which quantitatively test how the 21 classical and four higher-order Balmer-line Lick/IDS indices (Worthey et al. 1994; Worthey & Ottaviani 1997) depend on individual…

Astrophysics · Physics 2009-11-11 A. J. Korn , C. Maraston , D. Thomas

We present isochrone ages and initial bulk metallicities ($\rm [Fe/H]_{bulk}$, by accounting for diffusion) of 163,722 stars from the GALAH Data Release 2, mainly composed of main sequence turn-off stars and subgiants ($\rm 7000…

We report the abundances of 30 elements in 23 metal-poor ([Fe/H] <-1.7) giants. These are based on 7774 equivalent widths and spectral synthesis of 229 additional lines. Hyperfine splitting is taken into account when appropriate. Our choice…

Astrophysics · Physics 2016-08-30 Jennifer A. Johnson

Elemental abundances are key to our understanding of star formation and evolution in the Galactic center. Previous work on this topic has been based on infrared (IR) observations, but X-ray observations have the potential of constraining…

Astrophysics of Galaxies · Physics 2023-04-12 Ziqian Hua , Zhiyuan Li , Mengfei Zhang , Zhuo Chen , Mark R. Morris

We present predictions of the evolution of the light elements, Li, Be, and B, in the early epochs of the Galactic halo, using a model of supernova-induced chemical evolution based on contributions from supernovae (SNe) and cosmic rays…

Astrophysics · Physics 2009-10-31 Takeru Ken Suzuki , Yuzuru Yoshii

We present stellar evolution models for 0.5 - 1.2 \Msol at scaled metallicities of 0.1 - 1.5 Z\sol and O/Fe values of 0.44 - 2.28 O/Fe\sol. The time dependent evolution of habitable zone boundaries are calculated for each stellar evolution…

Solar and Stellar Astrophysics · Physics 2016-12-20 Amanda Truitt , Patrick A. Young , Alexander Spacek , Luke Probst , Jeremy Dietrich

The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogenous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in order to discuss the history of star…

Astrophysics · Physics 2007-05-23 Raffaele Gratton , Eugenio Carretta , Francesca Matteucci , Chris Sneden

Results from detailed spectroscopic analyses of stars hosting massive planets are employed to search for trends between abundances and condensation temperatures. The elements C, S, Na, Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni and Zn are…

Astrophysics · Physics 2009-11-13 Guillermo Gonzalez

The temporal behaviour of the radial abundance gradients has important consequences for models of the chemical evolution of the Galaxy. We present a comparison of the time variation of the abundance gradients in the Milky Way disk as…

Astrophysics · Physics 2009-11-10 W. J. Maciel , L. G. Lago , R. D. D. Costa

The upper Asymptotic Giant Branch is populated with oxygen rich and carbon rich Long Period Variables. These stars are essential contributors to the near-IR light of intermediate age stellar populations. Individual observed spectra of LPVs…

Astrophysics · Physics 2009-11-07 A. Lancon , M. Mouhcine

We present a catalog of uniformly determined stellar properties and abundances for 1626 F, G, and K stars using an automated spectral synthesis modeling procedure. All stars were observed using the HIRES spectrograph at Keck Observatory.…

Solar and Stellar Astrophysics · Physics 2016-08-24 John M. Brewer , Debra A. Fischer , Jeff A. Valenti , Nikolai Piskunov

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…

This is the fourth paper of our new release of the BaSTI (a Bag of Stellar Tracks and Isochrones) stellar model and isochrone library. Following the updated solar-scaled, alpha-enhanced, and white dwarf model libraries, we present here…

We present dense grids of stellar models suitable for comparison with observable quantities measured with great precision, such as those derived from binary systems or planet-hosting stars. We computed new Geneva models without rotation at…

Solar and Stellar Astrophysics · Physics 2015-06-03 N. Mowlavi , P. Eggenberger , G. Meynet , S. Ekstrom , C. Georgy , A. Maeder , C. Charbonnel , L. Eyer

We present a method for determining mean light-weighted ages and abundances of Fe, Mg, C, N, and Ca, from medium resolution spectroscopy of unresolved stellar populations. The method, pioneered by Schiavon (2007), is implemented in a…

Astrophysics · Physics 2009-11-13 Genevieve J. Graves , Ricardo P. Schiavon
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