Data reduction pipelines for the Very Large Telescope

Ballester, P.; Banse, Klaus; Castro, S.; Hanuschik, R. W.; Hook, R. N.; Izzo, C.; Jung, Yves; Kaufer, A.; Larsen, J.; Licha, T.; Lorch, H.; Lundin, Lars; Modigliani, A.; Palsa, Ralf; Peron, M.; Sabet, Cyrus; Vinther, J.

doi:10.1117/12.671229

Cited by 14 publications

(7 citation statements)

References 1 publication

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“…The spectra were reduced using the UVES context (Ballester et al 2000) within MIDAS, which performs bias and inter-order background subtraction (object and flatfield), optimal extraction of the object (rejecting cosmic ray hits), division by a flat-field frame extracted with the same optimally weighted profile as the object, wavelength calibration and rebinning to a constant value, and merging of all overlapping orders. The spectra were then co-added and finally normalized to unity in the continuum.…”

Section: Observations and Reductionsmentioning

confidence: 99%

First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy

Cayrel

Depagne

Spite

et al. 2004

A&A

1,106

246

1,891

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Abstract. In the framework of the ESO Large Programme "First Stars", very high-quality spectra of some 70 very metal-poor dwarfs and giants were obtained with the ESO VLT and UVES spectrograph. These stars are likely to have descended from the first generation(s) of stars formed after the Big Bang, and their detailed composition provides constraints on issues such as the nature of the first supernovae, the efficiency of mixing processes in the early Galaxy, the formation and evolution of the halo of the Galaxy, and the possible sources of reionization of the Universe. This paper presents the abundance analysis of an homogeneous sample of 35 giants selected from the HK survey of Beers et al. (1992Beers et al. ( , 1999, emphasizing stars of extremely low metallicity: 30 of our 35 stars are in the range −4.1 < [Fe/H] < −2.7, and 22 stars have [Fe/H] < −3.0. Our new VLT/UVES spectra, at a resolving power of R ∼ 45 000 and with signal-to-noise ratios of 100-200 per pixel over the wavelength range 330-1000 nm, are greatly superior to those of the classic studies of McWilliam et al. (1995) and Ryan et al. (1996). The immediate objective of the work is to determine precise, comprehensive, and homogeneous element abundances for this large sample of the most metal-poor giants presently known. In the analysis we combine the spectral line modeling code "Turbospectrum" with OSMARCS model atmospheres, which treat continuum scattering correctly and thus allow proper interpretation of the blue regions of the spectra, where scattering becomes important relative to continuous absorption (λ < 400 nm). We obtain detailed information on the trends of elemental abundance ratios and the star-to-star scatter around those trends, enabling us to separate the relative contributions of cosmic scatter and observational/analysis errors. Abundances of 17 elements from C to Zn have been measured in all stars, including K and Zn, which have not previously been detected in stars with [Fe/H] < −3.0. Among the key results, we discuss the oxygen abundance (from the forbidden [OI] line), the different and sometimes complex trends of the abundance ratios with metallicity, the very tight relationship between the abundances of certain elements (e.g., Fe and Cr), and the high [Zn/Fe] ratio in the most metal-poor stars. Within the error bars, the trends of the abundance ratios with metallicity are consistent with those found in earlier literature, but in many cases the scatter around the average trends is much smaller than found in earlier studies, which were limited to lower-quality spectra. We find that the cosmic scatter in several element ratios may be as low as 0.05 dex. The evolution of the abundance trends and scatter with declining metallicity provides strong constraints on the yields of the first supernovae and their mixing into the early ISM. The abundance ratios found in our sample do not match the predicted yields from pair-instability hypernovae, but are consistent with element production by supernovae with progenitor masses up to 100 M . Mo...

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Section: Observations and Reductionsmentioning

confidence: 99%

First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy

Cayrel

Depagne

Spite

et al. 2004

A&A

1,106

246

1,891

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“…The MUSE data were reduced with the VLT/MUSE standard pipeline (Ballester et al 2006) and photometrically calibrated with an observatory-selected white dwarf star.…”

Section: Muse Observationsmentioning

confidence: 99%

Analysis of gaseous ammonia (NH3) absorption in the visible spectrum of Jupiter

Irwin

Bowles

Braude

et al. 2018

Icarus

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This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights • Available sources of ammonia absorption in visible/near-IR compared and analysed • Band data of Bowles et al. (2008) found to combine best accuracy and coverage • Find absence of reliable absorption data below 0.758 µm under Jovian conditions

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“…The data reduction process is described in detail in Giles et al [2017]. EsoRex, the ESO Recipe Execution Tool [Ballester et al, 2006], was initially used to combine nodded pairs into a single observation and to achieve wavelength calibration. Subsequent data reduction was performed independently of the EsoRex software.…”

Section: Data Reductionmentioning

confidence: 99%

Ammonia in Jupiter's Troposphere From High‐Resolution 5 μm Spectroscopy

Giles

Fletcher

Irwin

et al. 2017

Geophysical Research Letters

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Jupiter's tropospheric ammonia (NH 3) abundance is studied using spatially resolved 5 μm observations from the cryogenic high-resolution infrared spectrograph (CRIRES) at the European Southern Observatory's Very Large Telescope. The high-resolving power (R = 96, 000) allows the line shapes of three NH 3 absorption features to be resolved. We find that within the 1-4 bar pressure range, the NH 3 abundance decreases with altitude. The instrument slit was aligned north-south along Jupiter's central meridian, allowing us to search for latitudinal variability. There is considerable uncertainty in the large-scale latitudinal variability, as the increase in cloud opacity in zones compared to belts can mask absorption features. However, we do find evidence for a strong NH 3 enhancement at 4-6 ∘ N, consistent with a localized "ammonia plume" on the southern edge of Jupiter's North Equatorial Belt.

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Data reduction pipelines for the Very Large Telescope

Cited by 14 publications

References 1 publication

First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy

First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy

Analysis of gaseous ammonia (NH3) absorption in the visible spectrum of Jupiter

Ammonia in Jupiter's Troposphere From High‐Resolution 5 μm Spectroscopy

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