Search results for "Universe"

Spectroscopic factors Influencing on the Atmospheric Radiative Transfer Modeling for the Methane Total Amount Retrieval

2010

First Applications of New Methane Linelists to the Modelling of Titan's Spectrum in the 1.58 and 1.28 Micron Windows

2010

Analysis of the High-Resolution FTIR Spectrum of Methane 12CH4 and 13CH4 in the 0–4800 cm-1 Spectral Region

2010

Near-Infrared Radiative Transfer Modeling with Different CH4 Databases to Retrieve Atmospheric Methane Total Amount

2010

Applications of a New Methane Linelist to the Modeling of Titan's Spectrum in the 1.58 Micron Window

2011

International audience

N2 Collosional Broadening of Methane int the THz Region Measured at the SOLEIL Synchrotron

2010

The INTEGRAL/SPI response and the Crab observations

2004

The Crab region was observed several times by INTEGRAL for calibration purposes. This paper aims at underlining the systematic interactions between (i) observations of this reference source, (ii) in-flight calibration of the instrumental response and (iii) the development and validation of the analysis tools of the SPI spectrometer. It first describes the way the response is produced and how studies of the Crab spectrum lead to improvements and corrections in the initial response. Then, we present the tools which were developed to extract spectra from the SPI observation data and finally a Crab spectrum obtained with one of these methods, to show the agreement with previous experiments. We …

ECLAIRs: A microsatellite for the prompt optical and X-ray emission of Gamma-Ray Bursts

2001

The prompt gamma-ray emission of Gamma-Ray Bursts (GRBs) is currently interpreted in terms of radiation from electrons accelerated in internal shocks in a relativistic fireball. On the other hand, the origin of the prompt (and early afterglow) optical and X-ray emission is still debated, mostly because very few data exist for comparison with theoretical predictions. It is however commonly agreed that this emission hides important clues on the GRB physics and can be used to constrain the fireball parameters, the acceleration and emission processes and to probe the surroundings of the GRBs. ECLAIRs is a microsatellite devoted to the observation of the prompt optical and X-ray emission of GRBs…

Results from the ULTRA experiment in the framework of the EUSO project

2005

The detection of Cerenkov light from EAS in a delayed coincidence with fluorescence light gives a strong signature to discriminate protons and neutrinos in cosmic rays. For this purpose, the ULTRA experiment has been designed with 2 detectors: a small EAS array (ETscope) and an UV optical device including wide field (Belenos) and narrow field (UVscope) Cerenkov light detectors. The array measures the shower size and the arrival direction of the incoming EAS, while the UV devices, pointing both to zenith and nadir, are used to determine the amount of direct and diffused coincident Cerenkov light. This information, provided for different diffusing surfaces, will be used to verify the possibil…

Detection of the Cherenkov light diffused by sea water with the ULTRA experiment

2007

The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together with isotropic emission of UV fluorescence light and highly directional Cherenkov photons, that are reflected/diffused isotropically by the impact on the Earth's surface or on high optical depth clouds. For space-based observations, detecting the reflected Cherenkov signal in a delayed coincidence with the fluorescence light improves the accuracy of the shower reconstruction in space and in particular the measurement of the shower maximum, …