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Related papers: Carbon in Red Giants in Globular Clusters and Dwar…

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Among stars in Galactic globular clusters the carbon abundance tends to decrease with increasing luminosity on the upper red giant branch, particularly within the lowest metallicity clusters. While such a phenomena is not predicted by…

Solar and Stellar Astrophysics · Physics 2019-04-08 Jeffrey M. Gerber , Michael M. Briley , Graeme H. Smith

Measurements of [C/Fe], [Ca/H], and [Fe/H] have been derived from Keck I LRISb spectra of 35 giants in the Draco dwarf spheroidal galaxy. The iron abundances are derived by a spectrum synthesis modeling of the wavelength region from 4850 to…

Astrophysics of Galaxies · Physics 2013-03-14 Matthew D. Shetrone , Graeme H. Smith , Laura M. Stanford , Michael H. Siegel , Howard E. Bond

We present [C/Fe] and [N/Fe] abundance ratios and CH({\lambda}4300) and S({\lambda}3883) index measurements for 94 red giant branch (RGB) stars in the Sculptor dwarf spheroidal galaxy from VLT/VIMOS MOS observations at a resolving power R=…

Astrophysics of Galaxies · Physics 2016-01-06 C. Lardo , G. Battaglia , E. Pancino , D. Romano , T. J. L. de Boer , E. Starkenburg , E. Tolstoy , M. J. Irwin , P. Jablonka , M. Tosi

We present the results of an observational study of the efficiency of deep mixing in globular cluster red giants as a function of stellar metallicity. We determine [C/Fe] abundances based on low-resolution spectra taken with the Kast…

Astrophysics · Physics 2009-11-13 Sarah L. Martell , Graeme H. Smith , Michael M. Briley

We have used UVES on VLT-UT2 to take spectra of 15 red giants in the Sculptor, Fornax, Carina and Leo I dwarf spheroidal galaxies. We measure the abundances of alpha, iron peak, s and r-process elements. No dSph giants in our sample show…

Astrophysics · Physics 2011-03-28 M. Shetrone , K. A. Venn , E. Tolstoy , F. Primas , V. Hill , A. Kaufer

It is well known that metal-poor red giant branch (RGB) stars show variations in some elemental abundances, including carbon, due to the internal mixing accompanied by their own in situ CN cycle in the hydrogen burning shell. With our new…

Astrophysics of Galaxies · Physics 2023-06-28 Jae-Woo Lee

We present a catalog of Fe, Mg, Si, Ca, and Ti abundances for 2961 red giant stars that are likely members of eight dwarf satellite galaxies of the Milky Way (MW): Sculptor, Fornax, Leo I, Sextans, Leo II, Canes Venatici I, Ursa Minor, and…

We have used high-resolution, high signal-to-noise spectra obtained with the VLT and UVES to determine abundances of 17 elements in 4 red giants in the Sculptor dwarf spheroidal galaxy. Our [Fe/H] values range from --2.10 to --0.97,…

We present an abundance analysis based on high resolution spectra of 8 stars selected to span the full range in metallicity in the Draco dwarf spheroidal galaxy. We find [Fe/H] for the sample stars ranges from -1.5 to -3.0 dex. Combining…

Astrophysics of Galaxies · Physics 2009-08-05 Judith G. Cohen , Wenjin Huang

We report on the chemical abundances derived from high-dispersion spectra of 14 red giant stars in the Sagittarius dwarf spheroidal (Sgr dSph) galaxy. The stars span a wide range of metallicities, -1.6 < [Fe/H] < -0.1 dex, and exhibit very…

Astrophysics · Physics 2007-05-23 Tammy A. Smecker-Hane , Andrew McWilliam

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

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

With the HDS (High Dispersion Spectrograph) on the Subaru telescope, we obtained high resolution optical region spectra of three red giant stars (cos 4, cos 82, and cos 347) in the Ursa Minor dwarf spheriodal galaxy. Chemical abundances in…

Astrophysics · Physics 2015-06-24 K. Sadakane , N. Arimoto , C. Ikuta , W. Aoki , P. Jablonka , A. Tajitsu

We present measurements of the abundances of chromium, cobalt, and nickel in 4113 red giants, including 2277 stars in globular clusters, 1820 stars in the Milky Way's dwarf satellite galaxies, and 16 field stars. We measured the abundances…

Solar and Stellar Astrophysics · Physics 2019-07-01 Evan N. Kirby , Justin L. Xie , Rachel Guo , Mikhail Kovalev , Maria Bergemann

The most metal-poor stars in dwarf spheroidal galaxies (dSphs) can show the nucleosynthetic patterns of one or a few supernovae. These supernovae could have zero metallicity, making metal-poor dSph stars the closest surviving links to…

Astrophysics of Galaxies · Physics 2012-11-12 Evan N. Kirby , Judith G. Cohen

A non-LTE analysis of K I resonance lines at 7664.91 and 7698.97 A was carried out for 15 red giants belonging to three globular clusters of different metallicity (M 4, M 13, and M 15) along with two reference early-K giants (rho Boo and…

Solar and Stellar Astrophysics · Physics 2015-05-13 Y. Takeda , H. Kaneko , N. Matsumoto , S. Oshino , H. Ito , T. Shibuya

The behaviour of the Delta nu =2 CO bands around 2.3 micron was examined by comparing observed and synthetic spectra in stars in globular clusters of different metallicity. Changes in the 12C/13C isotopic ratio and the carbon abundances…

Astrophysics · Physics 2009-11-10 Yakiv V. Pavlenko , Hugh R. A. Jones , Andrew J. Longmore

ABRIDGED: To compare the chemistries of stars in the Milky Way dSph galaxies with stars in the Galaxy, we have compiled a large sample of Galactic stellar abundances from the literature. As found in previous studies, the [alpha/Fe] ratios…

Astrophysics · Physics 2009-11-10 K. A. Venn , M. Irwin , M. D. Shetrone , C. A. Tout , V. Hill , E. Tolstoy

We use measurements of nitrogen abundances in red giants to search for multiple stellar populations in the four most metal-poor globular clusters (GCs) in the Fornax dwarf spheroidal galaxy (Fornax 1, 2, 3, and 5). New imaging in the F343N…

Astrophysics of Galaxies · Physics 2015-06-22 S. S. Larsen , J. P. Brodie , F. Grundahl , J. Strader

We present the non-local thermodynamic equilibrium (NLTE) abundances of up to 10 chemical species in a sample of 59 very metal-poor (VMP, -4 < [Fe/H] < -2) stars in seven dwarf spheroidal galaxies (dSphs) and in the Milky Way (MW) halo. Our…

Solar and Stellar Astrophysics · Physics 2017-12-27 L. Mashonkina , P. Jablonka , T. Sitnova , Yu. Pakhomov , P. North
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