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Related papers: Extremely metal-poor stars from the SDSS

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We summarize the progress in identifying and observational study of extremely metal-deficient (XMD) gas-rich galaxies (BCGs, dIr and LSBDs). Due to volume limitations only following issues are addressed: sample creation, some statistical…

Astrophysics · Physics 2009-11-07 S. Pustilnik , A. Kniazev , A. Pramskij , A. Ugryumov

In the search for metal-poor stars, large spectroscopic surveys are an invaluable tool. However, the spectra of metal-poor stars can be difficult to analyse because of the relative lack of available lines, which can also lead to…

We present the discovery of twelve metal-poor and distant pre-main sequence (PMS) candidates in the dwarf irregular galaxy Wolf-Lundmark-Melotte (WLM)~968 kpc away, at a present-day metallicity of [Fe/H] around $-$0.9. These candidates have…

Solar and Stellar Astrophysics · Physics 2025-01-30 Venu M. Kalari , Ricardo Salinas , Morten Andersen , Guido De Marchi , Monica Rubio , Jorick S. Vink , Hans Zinnecker

We analyze a high-resolution, high signal-to-noise spectrum of the carbon-rich, extremely metal-poor star CS29498-043, obtained with the Subaru Telescope High Dispersion Spectrograph. We find its iron abundance is extremely low ([Fe/H] =…

Astrophysics · Physics 2009-11-07 W. Aoki , J. E. Norris , S. G. Ryan , T. C. Beers , H. Ando

We have initiated a new survey for local extremely metal-poor galaxies (EMPGs) with Subaru/Hyper Suprime-Cam (HSC) large-area (~500 deg^2) optical images reaching a 5 sigma limit of ~26 magnitude, about 100 times deeper than the Sloan…

We present chemical abundances for 21 elements (from Li to Eu) in 150 metal-poor Galactic stars spanning $-$4.1 $<$ [Fe/H] $<$ $-$2.1. The targets were selected from the SkyMapper survey and include 90 objects with [Fe/H] $\le$ $-$3 of…

We present the results of an abundance analysis for a sample of stars with $-4<$[Fe/H]$<-2$. The data were obtained with the HIRES spectrograph at Keck Observatory. The set includes 28 stars, with effective temperature ranging from 4800 to…

Approximately 20% of very metal-poor stars ([Fe/H] < -2.0) are strongly enhanced in carbon ([C/Fe] > +1.0). Such stars are referred to as carbon-enhanced metal-poor (CEMP) stars. We present a chemical abundance analysis based on high…

Solar and Stellar Astrophysics · Physics 2015-05-14 N. T. Behara , P. Bonifacio , H. -G. Ludwig , L. Sbordone , J. I. Gonzalez Hernandez , E. Caffau

We collected near-infrared spectra of 65 cool stars with the NASA InfraRed Telescope Facility (IRTF) and analyze them to calculate accurate metallicities and stellar parameters. The sample of 55 M dwarfs and 10 K dwarfs includes 25 systems…

We present a spectroscopic study of eight extremely low-metallicity candidate emission-line galaxies with oxygen abundances possibly below 12 +log O/H = 7.35. These galaxies were selected from Data Release 10 of the Sloan Digital Sky…

Astrophysics of Galaxies · Physics 2015-06-24 N. G. Guseva , Y. I. Izotov , K. J. Fricke , C. Henkel

We report the discovery of stars that show spectra very close to the black-body radiation. We found 17 such stars out of 798,593 stars in the Sloan Digital Sky Survey (SDSS) spectroscopic data archives. We discuss the value of these stars…

Solar and Stellar Astrophysics · Physics 2018-10-31 Nao Suzuki , Masataka Fukugita

We present a high-resolution elemental-abundance analysis for a sample of 23 very metal-poor (VMP; [Fe/H] < -2.0) stars, 12 of which are extremely metal-poor (EMP; [Fe/H] < -3.0), and 4 of which are ultra metal-poor (UMP; [Fe/H] < -4.0).…

Solar and Stellar Astrophysics · Physics 2015-07-15 T. Hansen , C. J. Hansen , N. Christlieb , T. C. Beers , D. Yong , M. S. Bessell , A. Frebel , A. E. Garcia Perez , V. M. Placco , J. E. Norris , M. Asplund

We present homogeneous abundance analysis of over 20 elements for 385 very metal-poor (VMP) stars based on the LAMOST survey and follow-up observations with the Subaru Telescope. It is the largest high-resolution VMP sample (including 363…

We have identified 317 stars included in the Hipparcos astrometric catalogue which have parallaxes measured to a precision of better than 15%, and whose location in the (M_V, (B-V)_T) diagram implies a metallicity comparable to or less than…

Astrophysics · Physics 2009-10-31 I. Neill Reid , F. van Wyk , F. Marang , G. Roberts , D. Kilkenny , S. Mahoney

As part of the Dwarf galaxies Abundances and Radial-velocities Team (DART) program, we have measured the metallicities of a large sample of stars in four nearby dwarf spheroidal galaxies (dSph's): Sculptor, Sextans, Fornax, and Carina. The…

We describe a new method to search for metal-poor candidates from the Hamburg/ESO objective-prism survey (HES) based on identifying stars with apparently strong CH G-band strengths for their colors. The hypothesis we exploit is that large…

We aim at developing an efficient method to search for late-type subdwarfs (metal-depleted dwarfs with spectral types >M5) to improve the current statistics. Our objectives are: improve our knowledge of metal-poor low-mass dwarfs, bridge…

Solar and Stellar Astrophysics · Physics 2017-02-08 N. Lodieu , M. Espinoza Contreras , M. R. Zapatero Osorio , E. Solano , M. Aberasturi , E. L. Martin , C. Rodrigo

The fifth-generation Sloan Digital Sky Survey (SDSS-V) is conducting the first all-sky low-resolution spectroscopic survey of the Milky Way's stellar halo. We describe the stellar parameter pipeline for the SDSS-V halo survey, which…

We report on two major surveys for metal-poor stars in the galactic halo, the HK survey, and the Hamburg/ESO survey, which have been undertaken in order to provide targets for high-resolution spectroscopy with the Subaru HDS and other large…

Astrophysics · Physics 2007-05-23 Norbert Christlieb , Timothy C. Beers

We have determined Li abundances for eleven metal-poor turn-off stars, among which eight have [Fe/H]<-3, based on LTE analyses of high-resolution spectra obtained with the HDS on the Subaru telescope. The Li abundances for four of these…

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