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Related papers: Carbon in the Draco Dwarf Spheroidal Galaxy

200 papers

We investigate the spatial distribution, kinematics, and metallicity of stars in the Draco dwarf spheroidal galaxy using data from the Dark Energy Spectroscopic Instrument (DESI). We identify 155 high probability members of Draco using line…

High-resolution infrared spectra (R=50,000) have been obtained for twelve red-giant members of the LMC with the Gemini South 8.3-meter telescope plus Phoenix spectrometer. Quantitative chemical abundances of carbon-12, carbon-13,…

We aim to constrain the chemo-dynamical properties of the Sagittarius (Sgr) dwarf galaxy using carbon abundances. Our sample from the \textit{Pristine} Inner Galaxy Survey (PIGS) includes $\sim 350$ metal-poor ([Fe/H]~$<-1.5$) stars in the…

Low mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used to better understand their…

Astrophysics of Galaxies · Physics 2016-03-09 P. François , L. Monaco , P. Bonifacio , C. Moni Bidin , D. Geisler , L. Sbordone

We present a Magellan/MIKE high-resolution (R ~ 35,000) spectrum of the ancient star SD 1313-0019 which has an iron abundance of [Fe/H] = -5.0, paired with a carbon enhancement of [C/Fe] ~ 3.0. The star was initially identified by Allende…

Solar and Stellar Astrophysics · Physics 2015-09-23 Anna Frebel , Anirudh Chiti , Alexander P. Ji , Heather R. Jacobson , Vinicius M. Placco

Infrared OH lines at 1.55 - 1.56 um in the H-band were obtained with the Phoenix high-resolution spectrograph at the 2.1m telescope of the Kitt Peak National Observatory for a sample of 14 metal-poor stars. Detailed analyses of the sample…

Astrophysics · Physics 2011-02-11 Jorge Melendez , Beatriz Barbuy , Francois Spite

We present Keck/HIRES observations of six metal-poor stars in two of the ultra-faint dwarf galaxies orbiting the Milky Way, Ursa Major II and Coma Berenices. These observations include the first high-resolution spectroscopic observations of…

Astrophysics of Galaxies · Physics 2009-12-17 Anna Frebel , Joshua D. Simon , Marla Geha , Beth Willman

We have analyzed high-resolution and high signal-to-noise ratio optical spectra of nearby FGK stars with and without detected giant planets in order to homogeneously measure their photospheric parameters, mass, age, and the abundances of…

Solar and Stellar Astrophysics · Physics 2015-07-29 R. da Silva , A. C. Milone , H. J. Rocha-Pinto

In this paper we demonstrate how Stromgren uvby photometry can be efficiently used to: 1. Identify red giant branch stars that are members in a dwarf spheroidal galaxy. 2. Derive age-independent metallicities for the same stars and quantify…

Astrophysics · Physics 2009-11-11 D. Faria , S. Feltzing , I. Lundstrom , G. Gilmore , G. M. Wahlgren , A. Ardeberg , P. Linde

Deriving accurate carbon abundance estimates for a wide variety of stars is still complex due to the difficulties in properly measuring it from atomic and molecular lines. The aim of this paper is to analyse the carbon abundance…

The Hipparcos orbiting observatory has revealed a large number of helium-core-burning "clump" stars in the Galactic field. These low-mass stars exhibit signatures of extra-mixing processes that require modeling beyond the first dredge-up of…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Tautvaisiene , B. Edvardsson , E. Puzeras , G. Barisevicius , I. Ilyin

We present the abundances of Li, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Zn, Sr, Y, Zr, and Ba in a wide metallicity range ($-2.8 \le$ [Fe/H] $\le -1.5$). Using the differential technique allowed us to obtain an unprecedented low…

Solar and Stellar Astrophysics · Physics 2017-12-06 Henrique Reggiani , Jorge Meléndez , Chiaki Kobayashi , Amanda Karakas , Vinicius Placco

The earliest assembly of the Milky Way remains poorly understood, yet the spatial, chemical, and kinematic properties of its most metal-poor stars provide a unique fossil record of its proto-Galaxy phase. Understanding how this ancient…

We present new measurements of the gas-phase C/O abundance ratio in both the NW and SE components of the extremely metal-poor dwarf irregular galaxy I Zw 18, based on ultraviolet spectroscopy of the two H II regions using the Faint Object…

Astrophysics · Physics 2009-10-28 D. R. Garnett , E. D. Skillman , R. J. Dufour , G. A. Shields

We report R- and V-band photometry derived from CCD imaging for objects in nine fields in and around the Draco dwarf spheroidal galaxy. The most distant fields are about 1.3 degrees from the center. We use these data to search for Draco…

Astrophysics · Physics 2009-10-31 Slawomir Piatek , Carlton Pryor , Taft E. Armandroff , Edward W. Olszewski

We present a spectroscopic study of D461, a giant star belonging to Draco dwarf spheroidal galaxy. From spectral synthesis in LTE we derive a lithium abundance of log e(Li)=3.5+/-0.4 and a C/O ratio between 3 and 5. This is the first…

Astrophysics · Physics 2009-11-10 I. Dominguez , C. Abia , O. Straniero , S. Cristallo , Ya. V. Pavlenko

We present detailed chemical element abundance ratios of 17 elements in three metal poor stars in the Ursa Minor dwarf spheroidal galaxy, which we combine with extant data from the literature to assess the predictions of a novel suite of…

Astrophysics of Galaxies · Physics 2015-06-23 Ugur Ural , Gabriele Cescutti , Andreas Koch , Jan Kleyna , Sofia Feltzing , Mark I. Wilkinson

We report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity measurement is in good agreement with previous…

Astrophysics · Physics 2009-11-11 Jae-Woo Lee , Mercedes Lopez-Morales , Bruce W. Carney

We present 3D hydrodynamical simulations aimed to study the dynamical and chemical evolution of the interstellar medium in dwarf spheroidal galaxies. This evolution is driven by the explosions of Type II and Type Ia supernovae, whose…

Astrophysics · Physics 2009-11-11 A. Marcolini , A. D'Ercole , F. Brighenti , S. Recchi

We assemble 121 spectroscopically-confirmed halo carbon stars, drawn from the literature, exhibiting measurable variability in the Catalina Surveys. We present their periods and amplitudes, which are used to estimate distances from…

Astrophysics of Galaxies · Physics 2015-09-16 Avon Huxor , Eva Grebel