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Related papers: Manganese in dwarf spheroidal galaxies

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The Keck I telescope has been used to obtain HIRES spectra for red giants belonging to the Draco, Sextans and Ursa Minor dwarf spheroidal (dSph) galaxies. An analysis of these spectra is presented, along with abundance ratios for more than…

Astrophysics · Physics 2011-08-23 Matthew Shetrone , Patrick Cote , W. L. W. Sargent

The chemical compositions of evolved stars in Local Group dwarf spheroidal galaxies (dSphs) provide insight into the galaxy's past star formation and nucleosynthesis. Neutron-capture element abundances are especially interesting. In…

Astrophysics of Galaxies · Physics 2025-03-11 Lauren E. Henderson , Evan N. Kirby , Mithi A. C. de los Reyes , Roman Gerasimov , Viraj Manwadkar

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

We report on the abundance analysis of two red giants in the faint Hercules dwarf spheroidal (dSph) galaxy. These stars show a remarkable deficiency in the neutron-capture elements, while the hydrostatic alpha-elements (O, Mg) are strongly…

Astrophysics · Physics 2009-11-13 A. Koch , A. McWilliam , E. K. Grebel , D. B Zucker , V. Belokurov

We studied the chemical evolution of Dwarf Spheroidal (dSph) and Blue Compact Galaxies (BCGs) by means of comparison between the predictions of chemical evolution models and several observed abundance ratios. Detailed models with up to date…

Astrophysics · Physics 2009-11-10 Gustavo A. Lanfranchi , Francesca Matteucci

We investigate the evolution of the abundance of fluorine in the Milky Way thick and thin discs by means of detailed chemical evolution models compared with recent observational data. The chemical evolution models adopted here have already…

Astrophysics of Galaxies · Physics 2020-08-19 Valeria Grisoni , Donatella Romano , Emanuele Spitoni , Francesca Matteucci , Nils Ryde , Henrik Jönsson

We present abundances for seven stars in the (extremely) low-metallicity tail of the Sculptor dwarf spheroidal galaxy, from spectra taken with X-shooter on the ESO VLT. Targets were selected from the Ca II triplet (CaT) survey of the Dwarf…

The enrichment history of $r$-process elements has been imprinted on the stellar abundances that change in accordance with increasing metallicity in galaxies. Close examination of the [Eu/Fe] feature caused by stars in nearby galaxies,…

Astrophysics of Galaxies · Physics 2024-04-19 Takuji Tsujimoto

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…

The chemical abundances of stars in galaxies are a fossil record of the star formation and stellar evolution processes that regulate galaxy formation, including the stellar initial mass function, the fraction and timing of type Ia…

We present a homogeneous set of accurate atmospheric parameters for a complete sample of very and extremely metal-poor stars in the dwarf spheroidal galaxies (dSphs) Sculptor, Ursa Minor, Sextans, Fornax, Bo\"otes I, Ursa Major II, and Leo…

Solar and Stellar Astrophysics · Physics 2017-08-30 L. Mashonkina , P. Jablonka , Yu. Pakhomov , T. Sitnova , P. North

Dwarf irregular galaxies appear to have undergone very slow chemical evolution since they have low nebular abundances, but have had ongoing star formation over the past 15 Gyr. They are too distant for red giant abundance analyses to…

Astrophysics · Physics 2007-05-23 Kim Venn , Eline Tolstoy , Andreas Kaufer , Rolf Peter Kudritzki

We have used UVES on VLT-UT2 to take spectra of 15 individual red giant stars in the centers of four nearby dwarf spheroidal galaxies: Sculptor, Fornax, Carina and Leo I. We measure the abundance variations of numerous elements in these low…

Astrophysics · Physics 2011-08-23 Eline Tolstoy , K. A. Venn , M. Shetrone , F. Primas , V. Hill , A. Kaufer , T. Szeifert

Recent versions of the observed cosmic star-formation history (SFH) have resolved an inconsistency with the stellar mass density history. We show that the revised SFH also scales up the delay-time distribution (DTD) of Type Ia supernovae…

High Energy Astrophysical Phenomena · Physics 2017-10-18 Dan Maoz , Or Graur

Differential enrichment between $\alpha$- and Fe-peak elements is known to be strongly connected with the shape of the star formation history (SFH), the star formation efficiency (SFE), the inflow and outflow of material, and even the shape…

Detailed chemical composition of stars is of prime interest for a range of topics in modern stellar astrophysics, such as the chemical evolution of the Galaxy or the formation, composition, and structure of exoplanets. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-01-18 C. Duque-Arribas , H. M. Tabernero , D. Montes , J. A. Caballero

The Milky Way ultra-faint dwarf galaxies (UFDs) contain some of the oldest, most metal-poor stars in the Universe. We present [Mg/Fe], [Si/Fe], [Ca/Fe], [Ti/Fe], and mean [alpha/Fe], abundance ratios for 61 individual red giant branch stars…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Luis C. Vargas , Marla Geha , Evan N. Kirby , Joshua D. Simon

We have observed a sample of 19 carbon stars in the Sculptor, Carina, Fornax, and Leo I dwarf spheroidal galaxies with the Infrared Spectrograph on the Spitzer Space Telescope. The spectra show significant quantities of dust around the…

By means of chemo-photometric models for galaxies of different morhological types, we have carried out a detailed study of the history of element production by spheroidal and dwarf irregular galaxies. Spheroidal galaxies suffer a strong and…

Astrophysics · Physics 2009-11-11 Francesco Calura , Francesca Matteucci

The slow ($s$) and intermediate ($i$) neutron ($n$) capture processes occur both in asymptotic giant branch (AGB) stars, and in massive stars. To study the build-up of the $s$- and $i$-products at low metallicity, we investigate the…

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