Circumstellar Envelopes and Mass Loss of Red Giant Stars
- D. Reimers
- Physics, Geology
- 1975
The necessary incidence of mass loss from stars in advanced stages of evolution was recognized many years ago. Stars with masses above the white-dwarf limit m = 1.4m⊙ cannot stabilize themselves…
The Hamburg/ESO R-process enhanced star survey (HERES). II. Spectroscopic analysis of the survey sample
- P. Barklem, N. Christlieb, D. Reimers
- Physics
- 3 May 2005
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 snapshot spectra have been obtained with VLT/UVES and have…
HE 0557–4840: Ultra-Metal-Poor and Carbon-Rich
- J. Norris, N. Christlieb, D. Reimers
- Physics
- 18 July 2007
We report the discovery and high-resolution, high-S/N spectroscopic analysis of the ultra-metal-poor red giant HE 0557-4840, which is the third most heavy-element-deficient star currently known. Its…
High-resolution UVES/VLT spectra of white dwarfs observed for the ESO SN Ia Progenitor Survey - III. DA white dwarfs
- D. Koester, B. Voss, U. Heber
- Physics
- 17 August 2009
Context. The ESO Supernova Ia Progenitor Survey (SPY) took high-resolution spectra of more than 1000 white dwarfs and pre-white dwarfs. About two thirds of the stars observed are hydrogen-dominated…
The Fluctuating Intergalactic Radiation Field at Redshifts z = 2.3-2.9 from He II and H I Absorption toward HE 2347–4342
- J. Shull, J. Tumlinson, M. Giroux, G. Kriss, D. Reimers
- Physics
- 23 September 2003
We provide an in-depth analysis of the He II and H I absorption in the intergalactic medium (IGM) at redshifts z = 2.3-2.9 toward HE 2347-4342, using spectra from the Far Ultraviolet Spectroscopic…
HE 0437–5439: An Unbound Hypervelocity Main-Sequence B-Type Star
- H. Edelmann, R. Napiwotzki, U. Heber, N. Christlieb, D. Reimers
- Physics
- 10 November 2005
We report the discovery of a 16th magnitude star, HE 0437-5439, with a heliocentric radial velocity of +723 ± 3 km s-1. A quantitative spectral analysis of high-resolution optical spectra obtained…
The Evolution of Lyman-alpha Absorbers in the Redshift Range 0.5 < z < 1.9
- E. Janknecht, D. Reimers, S. López, D. Tytler
- Physics
- 16 August 2006
We investigate the evolution and the statistical properties of the Ly α absorbers of the intergalactic medium (IGM) in the largely unexplored redshift range z = 0.5−1.9. We use high-resolution (R ≥…
The UV spectrum of HS 1700+6416 - II. FUSE observations of the He II Lyman alpha forest
- C. Fechner, D. Reimers, W. Zheng
- Physics
- 5 May 2006
Aims. We present the far-UV spectrum of the quasar HS 1700+6416 taken with FUSE. This QSO provides the second line of sight with the He ii absorption resolved into a Lyα forest structure. Since HS…
NORMAL AND OUTLYING POPULATIONS OF THE MILKY WAY STELLAR HALO AT [Fe/H] <−2
- J. Cohen, N. Christlieb, E. Kirby
- Physics
- 6 October 2013
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…
High-resolution UVES/VLT spectra of white dwarfs observed for the ESO SN Ia progenitor survey - II. DB and DBA stars
- B. Voss, D. Koester, R. Napiwotzki, N. Christlieb, D. Reimers
- Physics
- 1 August 2007
Context. We present a detailed spectroscopic analysis of the stars with helium-dominated spectra in the ESO Supernova Ia Progenitor Survey (SPY). Aims. Atmospheric parameters, masses, and abundances…
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