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Article
Measurement of the radial velocity of the Sun as a star by means of a reflecting solar system body
Minor bodies of the solar system can be used to measure the spectrum of the Sun as a star by observing sunlight reflected by their surfaces. To perform an accurate measurement of the radial velocity of the Sun...
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Chapter and Conference Paper
Robust Limit on a Varying Proton-to-Electron Mass Ratio from a Single H2 System
The variation of the dimensionless fundamental physical constant \(\mu = {m}_{p}/{m}_{e}\) can be checked through observation...
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Chapter and Conference Paper
Searching for Chameleon-Like Scalar Fields
Using the 32-m Medicina, 45-m Nobeyama, and 100-m Effelsberg telescopes we found a statistically significant velocity offset ΔV ≈ 27 ± 3 m s − 1 (1σ) between the inversion transition in NH3(1,1) and low-J rotatio...
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Chapter and Conference Paper
The ESO Large Programme “First Stars”
In ESO period 65 (April–September 2000) the large programme 165.N-0276, led by Roger Cayrel, began making use of UVES at the Kueyen VLT telescope. Known within the Team and outside as “First Stars”, it was aim...
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Chapter and Conference Paper
ESPRESSO: A High Resolution Spectrograph for the Combined Coudé Focus of the VLT
In the frame of the call for proposal for the E-ELT instrumentation studies, the CODEX team carried out the feasibility study for a spectrograph for extremely stable Doppler measurements. The CODEX project and...
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Chapter and Conference Paper
From ESPRESSO to CODEX
CODEX and ESPRESSO are concepts for ultra-stable, high-resolution spectrographs at the E-ELT and VLT, respectively. Both instruments are well motivated by distinct sets of science drivers. However, ESPRESSO wi...
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Article
Bounds on the fine structure constantvariability from Fe ii absorption lines in QSO spectra
The Single Ion Differential α Measurement (SIDAM)method for measuring Δα/α and its figures of merit are illustrated together withthe results produced by means of Fe ii absorption linesof QSO intervening systems. ...
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Chapter and Conference Paper
Codex
Many talks in this conference have shown the power of high resolution spectroscopy, coupled to high precision. A new spectrograph, fed by an Extremely Large Telescope, will have such a huge collecting power th...
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Chapter and Conference Paper
Abundances in Damped Lyα Galaxies
Damped Lyα galaxies provide a sample of young galaxies where chemical abundances can be derived throughout the whole universe with an accuracy comparable to that for the local universe. Despite a large spread ...
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Chapter and Conference Paper
Evidence of Mixing in Extremely Metal-Poor Giants
Thirty five extremely metal-poor (EMP) giants (22 of them with a metallicity [Fe/H] ≤ -3.0) have been observed with UVES at the VLT. In these stars the abundance of lithium carbon and nitrogen and also the 12C/13
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Chapter and Conference Paper
Abundance of Heavy Elements in Extremely Metal-Poor Stars
In the framework of the VLT Large program “First Stars” (165.N-0276(A)), we have measured the abundance of 13 heavy elements using high quality UVES spectra. In this paper, we report on the abundance of Sr and...
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Chapter and Conference Paper
Abundances in Sagittarius Stars
The Sagittarius dwarf spheroidal is a very complex galaxy, which has undergone prolonged star formation. From the very first high resolution chemical analysis of Sgr stars, conducted using spectra obtained dur...
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Article
Measurement of stellar age from uranium decay
The ages of the oldest stars in the Galaxy indicate when star formation began, and provide a minimum age for the Universe. Radioactive dating of meteoritic material1 and stars2 relies on comparing the present abu...
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Chapter and Conference Paper
Oxygen Abundances in Very Metal-Poor Stars
Oxygen abundances have been derived in a sample of very metal-poor stars from observations of the O i triplet at λλ7771–7775Å and OH lines in the near ultraviolet. A detailed NLTE analysis of iron lines has been ...
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Article
Spectroscopy of Giants of the Sagittarius Dwarf Galaxy
In this paper we present the first results of the analysis of intermediate resolution (Δλ ∼ 3.5 Å) spectra of giants of the Sagittarius dwarf galaxy acquired using the ESO NTT telescope. From the deep CCD phot...
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Chapter and Conference Paper
Spectroscopy of Giants of the Sagittarius DWARF Galaxy
In this paper we present the first results of the analysis of intermediate resolution (Δλ ~ 3.5 Å) spectra of giants of the Sagittarius dwarf galaxy acquired using the ESO NTT telescope. From the deep CCD phot...
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Article
On the Nature of Damped LYα Systems: Clues from Determinations of Elemental Abundance Ratios
We present a study of the [α/Fe-peak] and [N/α] abundance ratios in Damped Lyα (DLA) systems. By using ratios of undepleted elements ([S/Zn] and [N/S]) or when abundances of refractory elements are corrected b...
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Article
The Low Metallicity Tail of the Halo Metallicity Distribution Function
Ongoing spectroscopy and photometry of stars selected in the HK objective-prism/interference-filter survey of Beers and colleagues has resulted in the identification of many hundreds of additional stars in the...
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Chapter and Conference Paper
The Low Metallicity Tail of the Halo Metallicity Distribution Function
Ongoing spectroscopy and photometry of stars selected in the HK objective-prism/interference-filter survey of Beers and colleagues has resulted in the identification of many hundreds of additional stars in the...
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Chapter and Conference Paper
Neutral Nitrogen in Damped Lyman a Systems
Nitrogen abundance determinations in high-redshift galaxies are an important tool for understanding the first stages of galactic chemical evolution. The most intense NI lines, i.e. the triplets at rest wavelen...
