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Related papers: Investigating the Metallicity-Mixing Length Relati…

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Convective overshoot mixing is a critical ingredient of stellar structure models, but is treated in most cases by ad hoc extensions of the mixing-length theory for convection. Advanced theories which are both more physical and numerically…

Solar and Stellar Astrophysics · Physics 2022-11-16 Felix Ahlborn , Friedrich Kupka , Achim Weiss , Martin Flaskamp

It is still being debated whether the well-known metallicity - giant planet correlation for dwarf stars is also valid for giant stars. For this reason, having precise metallicities is very important. Different methods can provide different…

Earth and Planetary Astrophysics · Physics 2015-06-16 A. Mortier , N. C. Santos , S. G. Sousa , V. Zh. Adibekyan , E. Delgado Mena , M. Tsantaki , G. Israelian , M. Mayor

We calculate the stellar mass-metallicity relation at five epochs ranging to z~2.3. We quantify evolution in the shape of the mass-metallicity relation as a function of redshift; the mass-metallicity relation flattens at late times. There…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 H. Jabran Zahid , Margaret Geller , Lisa Kewley , Ho Seong Hwang , Daniel Fabricant , Michael Kurtz

Red giants in the updated APOGEE-Kepler catalogue, with estimates of mass, chemical composition, surface gravity and effective temperature, have recently challenged stellar models computed under the standard assumption of solar calibrated…

Solar and Stellar Astrophysics · Physics 2018-05-16 M. Salaris , S. Cassisi , R. P. Schiavon , A. Pietrinferni

The Humphreys-Davidson (HD) limit empirically defines a region of high luminosities (log L > 5.5) and low effective temperatures (T < 20kK) on the Hertzsprung-Russell Diagram in which hardly any supergiant stars are observed. Attempts to…

Solar and Stellar Astrophysics · Physics 2021-02-17 Avishai Gilkis , Tomer Shenar , Varsha Ramachandran , Adam S. Jermyn , Laurent Mahy , Lidia M. Oskinova , Iair Arcavi , Hugues Sana

In this work, we have taken advantage of the most recent accurate stellar characterizations carried out using asteroseismology, eclipsing binaries and interferometry to evaluate a comprehensive set of empirical relations for the estimation…

Solar and Stellar Astrophysics · Physics 2018-08-08 Andy Moya , Federico Zuccarino , William J. Chaplin , Guy R. Davies

We present a catalog of stellar parameters (effective temperature $T_{\rm eff}$, surface gravity $\log g$, age, and metallicity [Fe/H]) and elemental-abundance ratios ([C/Fe], [Mg/Fe], and [$\alpha$/Fe]) for some five million stars (4.5…

The effect of melting in planetary mantles plays a key role in their thermo-chemical evolution. Because of the laterally heterogeneous nature of melting, 3D numerical simulations are in principle necessary prohibiting us from exploring wide…

Earth and Planetary Astrophysics · Physics 2021-12-15 Kenny Vilella , Shunichi Kamata

Metallicity is a fundamental parameter that contributes to the physical characteristics of a star. However, the low temperatures and complex molecules present in M dwarf atmospheres make it difficult to measure their metallicities using…

The determination of the stellar parameters of M dwarfs is of prime importance in the fields of galactic, stellar and planetary astronomy. M stars are the least studied galactic component regarding their fundamental parameters. Yet, they…

Solar and Stellar Astrophysics · Physics 2015-05-27 V. Neves , X. Bonfils , N. C. Santos

Deriving metallicities for solar-like stars follows well-established methods, but for cooler stars such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been…

Observations show that star-forming galaxies reside on a tight three-dimensional plane between mass, gas-phase metallicity and star formation rate (SFR), which can be explained by the interplay between metal-poor gas inflows, SFR and…

Astrophysics of Galaxies · Physics 2018-06-06 Jorryt Matthee , Joop Schaye

Metal mixing plays critical roles in the enrichment of metals in galaxies. The abundance of elements such as Mg, Fe, and Ba in metal-poor stars help us understand the metal mixing in galaxies. However, the efficiency of metal mixing in…

Astrophysics of Galaxies · Physics 2017-04-12 Yutaka Hirai , Takayuki R. Saitoh

An analysis of H alpha and H beta spectra in a sample of 30 cool dwarf and subgiant stars is presented using MARCS model atmospheres based on the most recent calculations of the line opacities. A detailed quantitative comparison of the…

We describe an equilibrium model that links the metallicity of low-redshift galaxies to stellar evolution models. It enables the testing of different stellar initial mass functions and metal yields against observed galaxy metallicities. We…

Astrophysics of Galaxies · Physics 2015-06-23 Martin Harwit , Drew Brisbin

Context: The effective temperature is a key parameter governing the properties of a star. For stellar chemistry, it has the strongest impact on the accuracy of the abundances derived. Since Cepheids are pulsating stars, determining their…

Solar and Stellar Astrophysics · Physics 2020-09-16 B. Lemasle , M. Hanke , J. Storm , G. Bono , E. K. Grebel

We develop a simple analytical model that tracks galactic metallicities governed by star formation and feedback to gain insight from the observed galaxy stellar mass-metallicity relations over a large range of stellar masses and redshifts.…

Astrophysics of Galaxies · Physics 2015-08-06 Yu Lu , Guillermo A. Blanc , Andrew Benson

The alpha element to iron peak element ratio, for example [Mg/Fe], is a commonly applied indicator of the galaxy star formation timescale (SFT) since the two groups of elements are mainly produced by different types of supernovae that…

Astrophysics of Galaxies · Physics 2019-12-11 Zhiqiang Yan , Terea Jerabkova , Pavel Kroupa

Metallicity is one of the crucial factors that determine stellar evolution. To characterize the properties of stellar populations one needs to know the fraction of stars forming at different metallicities. Knowing how this fraction evolves…

Astrophysics of Galaxies · Physics 2019-07-29 Martyna Chruslinska , Gijs Nelemans
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