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Related papers: Extremely metal-poor stars in SDSS fields

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We present elemental abundances for eight unevolved extremely metal-poor stars with $T_{\rm eff}>5500\,\mathrm{K}$, among which seven have $[\mathrm{Fe/H}]<-3.5$. The sample is selected from the Sloan Digital Sky Survey / Sloan Extension…

Solar and Stellar Astrophysics · Physics 2017-07-26 Tadafumi Matsuno , Wako Aoki , Timothy C. Beers , Young Sun Lee , Satoshi Honda

The SkyMapper Southern Sky Survey is carrying out a search for the most metal-poor stars in the Galaxy. It identifies candidates by way of its unique filter set that allows for estimation of stellar atmospheric parameters. The set includes…

We present and discuss the results of a search for extremely metal-poor stars based on photometry from data release DR1.1 of the SkyMapper imaging survey of the southern sky. In particular, we outline our photometric selection procedures…

We present the high-resolution spectroscopic analysis of two new extremely metal-poor stars (EMPS) candidates in the dwarf spheroidal galaxy Sextans. These targets were pre-selected from medium resolution spectra centered around the Ca II…

Astrophysics of Galaxies · Physics 2021-01-04 R. Lucchesi , C. Lardo , F. Primas , P. Jablonka , P. North , G. Battaglia , E. Starkenburg , V. Hill , M. Irwin , P. Francois , M. Shetrone , E. Tolstoy , K. Venn

We report the discovery of one extremely metal-poor (EMP; [Fe/H]<-3) and one ultra metal-poor (UMP; [Fe/H]<-4) star selected from the SDSS/SEGUE survey. These stars were identified as EMP candidates based on their medium-resolution…

We give an update on our 0Z Survey to find more extremely metal poor (EMP) stars with [Fe/H] < -3 dex through mining the database of the Hamburg/ESO Survey. We present the most extreme such stars we have found from ~1550 moderate resolution…

Astrophysics · Physics 2009-06-23 J. G. Cohen , N. Christlieb , A. McWilliam , S. Shectman , I. Thompson

We have identified several tens of extremely metal-poor star candidates from SDSS and LAMOST, which we follow-up with the 4.2m WHT telescope to confirm their metallicity.We follow a robust two-step methodology. We first analyze the SDSS and…

Solar and Stellar Astrophysics · Physics 2017-09-06 D. S. Aguado , J. I. González Hernández , C. Allende Prieto , R. Rebolo

For a sample of metal-poor stars (-3.3< [Fe/H] <-2.2) that have high-resolution spectroscopic abundance determinations, we have measured equivalent widths (EW) of the Ca II K, Mg I b and near-infrared (NIR) Ca II triplet lines using…

Solar and Stellar Astrophysics · Physics 2015-06-12 Siyao Xu , Huawei Zhang , Xiaowei Liu

Stellar metallicity strongly correlates with the presence of planets and their properties. To check for new correlations between stars and the existence of an orbiting planet, we determine precise stellar parameters for a sample of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Sérgio G. Sousa , Nuno C. Santos , Garik Israelian , C. Lovis , Michel Mayor , Pedro B. Silva , Stephane Udry

We report on efforts to identify large samples of very and extremely metal-poor stars based on medium-resolution spectroscopy and ugriz photometry obtained during the course of the Sloan Digital Sky Survey (SDSS), and its extension,…

Astrophysics · Physics 2009-11-13 Timothy C. Beers , Daniela Carollo

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…

We present a detailed abundance analysis based on high resolution and high signal-to-noise spectra of eight extremely metal poor (EMP) stars with [Fe/H] < -3.5$ dex, four of which are new. Only stars with 4900 < Teff< 5650 K are included.…

Context: Studies of extremely metal-poor stars indicate that chemical abundance ratios [X/Fe] have an rms scatter as low as 0.05 dex (12 \%). It remains unclear whether this reflects observational uncertainties or intrinsic astrophysical…

Solar and Stellar Astrophysics · Physics 2016-03-09 Henrique Reggiani , Jorge Meléndez , David Yong , Ivan Ramírez , Martin Asplund

Extremely metal-poor stars provide us with indirect information on the first generations of massive stars. The TOPoS survey has been designed to increase the census of these stars and to provide a chemical inventory that is as detailed as…

We report on the discovery of seven low-metallicity stars selected from the Hamburg/ESO Survey, six of which are extremely metal-poor ([Fe/H]<-3.0), with four having [Fe/H]<-3.5. Chemical abundances or upper limits are derived for these…

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…

I report on recent results from observations of stars with metallicities [Fe/H] <= -2.0. These include a substantial new sample of objects with high-resolution observations obtained as part of a follow-up of the HK Survey, The Hamburg/ESO…

Astrophysics · Physics 2009-06-23 Timothy C. Beers

We present the results of spectroscopic follow-up for 1897 low-metallicity star candidates, selected from the Best & Brightest (B&B) Survey, carried out with the GMOS-N/S (Gemini North/South telescopes) and Goodman (SOAR Telescope)…

I review the status of the search for extremely metal-poor halo stars with the Hamburg/ESO objective-prism survey (HES). 2194 candidate metal-poor turn-off stars and 6133 giants in the magnitude range 14 < B < 17.5 have been selected from…

Astrophysics · Physics 2015-06-03 Norbert Christlieb