English
Related papers

Related papers: Manganese in dwarf spheroidal galaxies

200 papers

We present spectroscopic metallicities of individual stars in seven gas-rich dwarf irregular galaxies (dIrrs), and we show that dIrrs obey the same mass-metallicity relation as the dwarf spheroidal (dSph) satellites of both the Milky Way…

Astrophysics of Galaxies · Physics 2013-12-02 Evan N. Kirby , Judith G. Cohen , Puragra Guhathakurta , Lucy Cheng , James S. Bullock , Anna Gallazzi

Context. The [Mg/Fe] abundance ratios are a fundamental fossil signature to trace the chemical evolution of the disc. Despite of the huge observational and theoretical effort, discrepancies between models and data are still present and…

Astrophysics of Galaxies · Physics 2022-07-20 Marco Palla , Pablo Santos-Peral , Alejandra Recio-Blanco , Francesca Matteucci

Context. Recently, new sub-classes of Type Ia supernovae (SNe Ia) were discovered, including SNe Iax. The suggested progenitors of SNe Iax are relatively massive, possibly hybrid C+O+Ne white dwarfs, which can cause white dwarf winds at low…

Astrophysics of Galaxies · Physics 2017-11-01 Gabriele Cescutti , Chiaki Kobayashi

We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of type Ia supernovae recently revealed by type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Kenji Bekki , Takuji Tsujimoto

We investigate chemical evolution in Milky Way-like galaxies based on the cold dark matter model in which cosmic structures form via hierarchical merging. We introduce chemical enrichment due to type Ia supernovae (SNe Ia) into the Mitaka…

Astrophysics · Physics 2009-11-10 Masahiro Nagashima , Takashi Okamoto

The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies.…

Astrophysics · Physics 2009-11-10 Michael R. Corbin , Kirk T. Korista , Nalaka Kodituwakku , Wolfram Freduling

Sulfur abundances have been determined for ten stars to resolve a debate in the literature on the Galactic chemical evolution of sulfur in the halo phase of the Milky Way. Our analysis is based on observations of the S I lines at 9212.9,…

Astrophysics · Physics 2009-11-10 N. Ryde , D. L. Lambert

The elemental abundances of stars reflect the complex enrichment history of the galaxy. To explore and explain the metal enrichment history of the cosmic environment near our solar system, we study the evolution of $^{56} \mathrm{Fe}$…

High Energy Astrophysical Phenomena · Physics 2024-09-04 Yan-Qing Qi , Tong Liu , Mouyuan Sun , Zhen-Yi Cai

We report the results of a coherent study of three chemically anomalous metal-poor ([Fe/H] ~ -2) stars. These objects exhibit unusually low abundances of Mg, Si, Ca (alpha-elements) and Sr, Y, and Ba (neutron-capture elements). Our analyses…

The Sculptor dwarf spheroidal galaxy is old and metal-poor, making it ideal to study the earliest chemical enrichment in the Local Group. We followed up the most metal-poor star known in this (or any external) galaxy, AS0039, with…

Astrophysics of Galaxies · Physics 2024-01-10 Ása Skúladóttir , Irene Vanni , Stefania Salvadori , Romain Lucchesi

We present the elemental abundances and ages of 19 massive quiescent galaxies at $z\sim1.4$ and $z\sim2.1$ from the Keck Heavy Metal Survey. The ultra-deep LRIS and MOSFIRE spectra were modeled using a full-spectrum stellar population…

We have extended our analytical chemical evolution modelling ideas for the Galaxy to the Magellanic Clouds. Unlike previous authors, we assume neither a steepened IMF nor selective galactic winds, since among the alpha-particle elements…

Astrophysics · Physics 2009-07-28 B. E. J. Pagel , G. Tautvaisiene

We present a large sample of fully self-consistent hydrodynamical Nbody/Tree-SPH simulations of isolated dwarf spheroidal galaxies (dSphs). It has enabled us to identify the key physical parameters and mechanisms at the origin of the…

Astrophysics of Galaxies · Physics 2015-05-13 Y. Revaz , P. Jablonka , T. Sawala , V. Hill , B. Letarte , M. Irwin , G. Battaglia , A. Helmi , M. D. Shetrone , E. Tolstoy , K. A. Venn

We discuss oxygen and iron abundance patterns in K and M red-giant members of the Galactic bulge and in the young and massive M-type stars inhabiting the very center of the Milky Way. The abundance results from the different bulge studies…

Astrophysics · Physics 2009-11-13 K. Cunha , V. Smith , K. Sellgren , R. Blum , S. Ramirez , D. Terndrup

We present abundance results from our Keck/HIRES observations of giants in the Galactic Bulge. We confirm that the metallicity distribution of giants in the low-reddening bulge field Baade's Window can be well-fit by a closed-box enrichment…

Astrophysics · Physics 2009-11-10 Jon P. Fulbright , R. Michael Rich , Andrew McWilliam

While the Milky Way Nuclear star cluster has been studied extensively, how it formed is uncertain. Studies have shown it contains a solar and supersolar metallicity population that may have formed in-situ, along with a subsolar metallicity…

Astrophysics of Galaxies · Physics 2022-02-02 Rory O. Bentley , Tuan Do , Wolfgang Kerzendorf , Devin S. Chu , Zhuo Chen , Quinn Konopacky , Andrea Ghez

We present a new approach for chemical evolution modelling, specifically designed to investigate the chemical properties of dwarf galaxies in a full cosmological framework. In particular, we focus on the Sculptor dwarf spheroidal galaxy as…

Astrophysics of Galaxies · Physics 2015-06-16 Donatella Romano , Else Starkenburg

Based on high-resolution spectra obtained during gravitational microlensing events we present a detailed elemental abundance analysis of 32 dwarf and subgiant stars in the Galactic bulge. [ABRIDGED], we now have 58 microlensed bulge dwarfs…

We investigate the nature of the newly discovered Ultra Faint dwarf spheroidal galaxies (UF dSphs) in a general cosmological context simultaneously accounting for various ``classical`` dSphs and Milky Way properties including their…

Astrophysics · Physics 2009-11-13 Stefania Salvadori , Andrea Ferrara

We present the metallicity distribution of a sample of 471 RR Lyrae (RRL) stars in the Sculptor dSph, obtained from the $I$-band Period-Luminosity relation. It is the first time that the early chemical evolution of a dwarf galaxy is…