High-Resolution Spectroscopy from 3050 to 10000 Å of the Hubble Deep Field South QSO J2233−606 with UVES at the ESO Very Large Telescope

2000 ◽  
Vol 120 (4) ◽  
pp. 1648-1653 ◽  
Author(s):  
S. Cristiani ◽  
V. D’Odorico
Keyword(s):  
High Resolution ◽  
High Resolution Spectroscopy ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Hubble Deep Field

scholarly journals Interstellar Matter with Very Large Telescopes

1984 ◽  
Vol 79 ◽  
pp. 675-678
Author(s):  
J. Lequeux
Keyword(s):  
High Resolution ◽  
Absorption Lines ◽  
High Resolution Spectroscopy ◽  
Interstellar Matter ◽  
Large Telescope ◽  
Interstellar Absorption ◽  
Near Ir ◽  
Very Large Telescope ◽  
Large Telescopes ◽  
Diffuse Matter

Interstellar matter is certainly one of the fields where a very large telescope (VLT) will prove to be most fruitful. This includes (somewhat paradoxically, but this will be explained later) the study of extended emissions. I will now examine in turn the different domains of interest for a VLT.I. Neutral diffuse matterOptical and near IR observations will mainly contribute to this domain through high-resolution spectroscopy of interstellar absorption lines in the spectra of stars. These lines are resonant lines of atoms (NaI, KI, etc.) or ions (CaII, TiII, etc.) as well as of some molecules (CH+, CH, CN, CS+, C2 in the near IR). Clearly this kind of study is always photon - limited; a VLT will collect more photons than present telescopes, thus increase the possibilities considerably.

A Flash in the Dark: UVES Very Large Telescope High‐Resolution Spectroscopy of Gamma‐Ray Burst Afterglows

2005 ◽  
Vol 624 (2) ◽  
pp. 853-867 ◽  
Author(s):  
F. Fiore ◽  
V. D’Elia ◽  
D. Lazzati ◽  
R. Perna ◽  
L. Sbordone ◽  
...  
Keyword(s):  
High Resolution ◽  
Gamma Ray ◽  
High Resolution Spectroscopy ◽  
Large Telescope ◽  
Gamma Ray Burst ◽  
Very Large Telescope

scholarly journals Lithium abundance in lower red giant branch stars of Omega Centauri

2018 ◽  
Vol 618 ◽  
pp. A134 ◽  
Author(s):  
A. Mucciarelli ◽  
M. Salaris ◽  
L. Monaco ◽  
P. Bonifacio ◽  
X. Fu ◽  
...  
Keyword(s):  
High Resolution ◽  
Globular Clusters ◽  
Stellar System ◽  
The Other ◽  
Large Telescope ◽  
Lithium Abundance ◽  
Very Large Telescope ◽  
Red Giant ◽  
Giant Branch Stars ◽  
Branch Star

We present Li, Na, Al, and Fe abundances of 199 lower red giant branch star members of the stellar system Omega Centauri, using high-resolution spectra acquired with FLAMES at the Very Large Telescope. The A(Li) distribution is peaked at A(Li) ∼ 1 dex with a prominent tail towards lower values. The peak of the distribution well agrees with the lithium abundances measured in lower red giant branch stars in globular clusters and Galactic field stars. Stars with A(Li) ∼ 1 dex are found at metallicities lower than [Fe/H] ∼ –1.3 dex but they disappear at higher metallicities. On the other hand, Li-poor stars are found at all metallicities. The most metal-poor stars exhibit a clear Li–Na anti-correlation, where about 30% of the sample have A(Li) lower than ∼0.8 dex, while these stars represent a small fraction of normal globular clusters. Most of the stars with [Fe/H] > –1.6 dex are Li poor and Na rich. The Li depletion measured in these stars is not observed in globular clusters with similar metallicities and we demonstrate that it is not caused by the proposed helium enhancements and/or young ages. Hence, these stars formed from a gas already depleted in lithium. Finally, we note that Omega Centauri includes all the populations (Li-normal/Na-normal, Li-normal/Na-rich, and Li-poor/Na-rich stars) observed, to a lesser extent, in mono-metallic GCs.

scholarly journals Speckle Interferometry, Speckle Masking, Speckle Spectroscopy and Speckle Frame Selection

1984 ◽  
Vol 79 ◽  
pp. 337-345 ◽  
Author(s):  
Gerd Weigelt
Keyword(s):  
High Resolution ◽  
Speckle Interferometry ◽  
Large Telescope ◽  
Speckle Imaging ◽  
Frame Selection ◽  
Very Large Telescope

AbstractHigh-resolution speckle imaging is one of the most fascinating possibilities of a Very Large Telescope (VLT). Various speckle methods can yield a resolution of about 0.01" with a 8-m to 10-m VLT. As exiting as the resolution is the limiting magnitude of the speckle methods. The limiting magnitude is extremely seeingdependent. The following limiting magnitudes are possible with speckle interferometry, speckle masking and speckle spectroscopy:4" seeing: limiting magnitude 152" seeing: limiting magnitude 17.51" seeing: limiting magnitude 20 (!)

scholarly journals Comet 66P/du Toit: not a near-Earth main belt comet

2019 ◽  
Vol 631 ◽  
pp. A168
Author(s):  
Bin Yang ◽  
Emmanuël Jehin ◽  
Francisco J. Pozuelos ◽  
Youssef Moulane ◽  
Yoshiharu Shinnaka ◽  
...  
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Orbital Evolution ◽  
Abundance Ratio ◽  
High Resolution Spectroscopy ◽  
Main Belt ◽  
Gaseous Species ◽  
Very Large Telescope ◽  
Short Period ◽  
Dynamical Simulations

Context. Main belt comets (MBCs) are a peculiar class of volatile-containing objects with comet-like morphology and asteroid-like orbits. However, MBCs are challenging targets to study remotely due to their small sizes and the relatively large distance they are from the Sun and the Earth. Recently, a number of weakly active short-period comets have been identified that might originate in the asteroid main belt. Among all of the known candidates, comet 66P/du Toit has been suggested to have one of the highest probabilities of coming from the main belt. Aims. The main goal of this study is to investigate the physical properties of 66P via spectroscopic and imaging observations to constrain its formation conditions. In particular, the isotopic abundance ratio and the ortho-to-para ratio (OPR) of gaseous species can be derived via high-resolution spectroscopy, which is sensitive to the formation temperature of the nucleus. Methods. We obtained medium and high-resolution spectra of 66P from 300–2500 nm with the X-shooter and the UVES instruments at the Very Large Telescope in July 2018. We also obtained a series of narrow-band images of 66P to monitor the gas and dust activity between May and July 2018 with TRAPPIST-South. In addition, we applied a dust model to characterize the dust coma of 66P and performed dynamical simulations to study the orbital evolution of 66P. Results. We derive the OPR of ammonia (NH3) in 66P to be 1.08 ± 0.06, which corresponds to a nuclear spin temperature of ~34 K. We compute the production rates of OH, NH, CN, C3, and C2 radicals and measure the dust proxy, Afρ. The dust analysis reveals that the coma can be best-fit with an anisotropic model and the peak dust production rate is about 55 kg s−1 at the perihelion distance of 1.29 au. Dynamical simulations show that 66P is moderately asteroidal with the capture time, tcap ~ 104 yr. Conclusions. Our observations demonstrate that the measured physical properties of 66P are consistent with typical short-period comets and differ significantly from other MBCs. Therefore, 66P is unlikely to have a main belt origin.

Very Large Telescope–ISAAC Near-Infrared Spectroscopy of [ITAL]ISO[/ITAL]-selected Hubble Deep Field South Galaxies

2000 ◽  
Vol 537 (2) ◽  
pp. L85-L89 ◽  
Author(s):  
D. Rigopoulou ◽  
A. Franceschini ◽  
H. Aussel ◽  
R. Genzel ◽  
P. van der Werf ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Large Telescope ◽  
Very Large Telescope ◽  
Hubble Deep Field

scholarly journals Characterization of the Zonal Wind Flow in the Upper Atmosphere of Titan with the VLT

2005 ◽  
Vol 13 ◽  
pp. 897-897
Author(s):  
Régis Courtin ◽  
David Luz ◽  
Daniel Gautier ◽  
Thierry Appourchaux ◽  
Jean-Pierre Lebreton ◽  
...  
Keyword(s):  
High Resolution ◽  
Zonal Wind ◽  
Upper Atmosphere ◽  
Wind Flow ◽  
Large Telescope ◽  
Spectroscopic Observations ◽  
Very Large Telescope

AbstractWe report on recent efforts to characterize the zonal wind flow in the upper atmosphere of Titan from high resolution spectroscopic observations with the Very Large Telescope.

scholarly journals High resolution optical spectroscopy of the N2-rich comet C/2016 R2 (PanSTARRS)

2019 ◽  
Vol 624 ◽  
pp. A64 ◽  
Author(s):  
C. Opitom ◽  
D. Hutsemékers ◽  
E. Jehin ◽  
P. Rousselot ◽  
F. J. Pozuelos ◽  
...  
Keyword(s):  
High Resolution ◽  
Isotopic Ratio ◽  
Kuiper Belt ◽  
Large Telescope ◽  
Strong Emission ◽  
Kuiper Belt Object ◽  
Water Abundance ◽  
Very Large Telescope ◽  
First Time ◽  
Ch Radical

Context. Early observations of comet C/2016 R2 (PanSTARRS) have shown that the composition of this comet is very peculiar. Radio observations have revealed a CO-rich and HCN-poor comet and an optical coma dominated by strong emission bands of CO+ and, more surprisingly, N2+. Aims. The strong detection of N2+ in the coma of C/2016 R2 provided an ideal opportunity to measure the 14N∕15N isotopic ratio directly from N2+ for the first time, and to estimate the N2∕CO ratio, which is an important diagnostic to constrain formation models of planetesimals, in addition to the more general study of coma composition. Methods. We obtained high resolution spectra of the comet in February 2018 when it was at 2.8 au from the Sun. We used the UVES spectrograph of the European Southern Observatory Very Large Telescope, complemented with narrowband images obtained with the TRAPPIST telescopes. Results. We detect strong emissions from the N2+ and CO+ ions, but also CO2+, emission lines from the CH radical, and much fainter emissions of the CN, C2, and C3 radicals that were not detected in previous observations of this comet. We do not detect OH or H2O+, and we derive an upper limit of the H2O+∕CO+ ratio of 0.4, implying that the comet has a low water abundance. We measure a N2+/CO+ ratio of 0.06 ± 0.01. The non-detection of NH2 indicates that most of the nitrogen content of the comet is in N2. Together with the high N2+/CO+ ratio, this could indicate a low formation temperature of the comet or that the comet is a fragment of a large differentiated Kuiper Belt object. The CO2+/CO+ ratio is 1.1 ± 0.3. We do not detect 14N15N+ lines and can only put a lower limit on the 14N∕15N ratio (measured from N2+) of about 100, which is compatible with measurements of the same isotopic ratio for NH2 and CN in other comets. Finally, in addition to the [OI] and [CI] forbidden lines, we detect for the first time the forbidden nitrogen lines [NI] doublet at 519.79 and 520.03 nm in the coma of a comet.

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

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