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Related papers: A Status Report on the 0Z Project

200 papers

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

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

We present a detailed abundance analysis of 8 stars selected as extremely metal poor candidates from the Hamburg/ESO Survey (HES). For comparison, we have also analysed 3 extremely metal-poor candidates from the HK survey, and 3 additional…

In this series of two papers we present a high dispersion spectroscopic analysis of 8 candidate extremely metal poor stars selected from the Hamburg/ESO Survey and of 6 additional very metal poor stars. We demonstrate that with suitable…

We present a sample of 1777 bright (9<B<14) metal-poor candidates selected from the Hamburg/ESO Survey (HES). Despite saturation effects present in the red portion of the HES objective-prism spectra, the data were recoverable and…

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.…

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 report the discovery of 34 stars in the Hamburg/ESO Survey for metal-poor stars and the Sloan Digital Sky Survey that have [Fe/H] < -3.0. Their median and minimum abundances are [Fe/H] = -3.1 and -4.1, respectively, while 10 stars have…

We have now completed detailed abundance analyses of more than 100 stars selected as candidate extremely metal-poor stars with [Fe/H] < -3.0 dex. Of these 18 are below -3.3 dex on the scale of the First Stars VLT project led by Cayrel, and…

Astrophysics of Galaxies · Physics 2012-01-23 Judith G. Cohen , Norbert Christlieb , Ian Thompson , Andrew McWilliam , Stephen Shectman

We discuss the detailed composition of 28 extremely metal-poor dwarfs, 22 of which are from the Hamburg/ESO Survey, based on Keck Echelle spectra. Our sample has a median [Fe/H] of -2.7 dex, extends to -3.5 dex, and is somewhat less…

We present a homogeneous chemical abundance analysis of 16 elements in 190 metal-poor Galactic halo stars (38 program and 152 literature objects). The sample includes 171 stars with [Fe/H] < -2.5, of which 86 are extremely metal poor,…

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…

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

From detailed abundance analysis of >100 Hamburg/ESO candidate extremely metal-poor (EMP) stars we find 45 with [Fe/H] < -3.0 dex. We identify a heretofore unidentified group: Ca-deficient stars, with sub-solar [Ca/Fe] ratios and the lowest…

An automated search for metal-poor stars is carried out in the course of the Hamburg/ESO objective-prism survey (HES), which covers the full southern sky at Galactic latitudes |b| \gtrsim 30 degrees. As the HES reaches approx. 1 magnitude…

We report on a search for extremely metal-poor ([Fe/H]<-3.0) turnoff stars in the Hamburg/ESO objective prism survey (HES). Metal-poor stars are selected by automatic spectral classification. Extensive simulations show that the selection…

Astrophysics · Physics 2009-10-31 N. Christlieb , D. Reimers , L. Wisotzki , J. Reetz , T. Gehren , T. C. Beers

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 present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High…

We present the results of analysis of ``snapshot'' spectra of 253 metal-poor halo stars -3.8 < [Fe/H] < -1.5 obtained in the HERES survey. The spectra are analysed using an automated line profile analysis method based on the Spectroscopy…

The most metal-poor stars in the Milky Way witnessed the early phases of formation of the Galaxy, and have chemical compositions that are close to the pristine mixture from Big Bang nucleosynthesis, polluted by one or few supernovae. Only…

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