arXiv subjects

S. Toscano

Publications and source records attributed to S. Toscano.

42 records · Page 3Linked to original sources

arXiv2015

The Atmospheric Monitoring System of the JEM-EUSO Space Mission

An Atmospheric Monitoring System (AMS) is a mandatory and key device of a space-based mission which aims to detect Ultra-High Energy Cosmic Rays (UHECR) and Extremely-High Energy Cosmic Rays (EHECR) from Space. JEM-EUSO has a dedicated atmospheric monitoring system that plays a fundamental role in our understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. Our AMS consists of a very challenging space infrared camera and a LIDAR device, that are being fully designed with space qualification to fulfil the scientific requirements of this space mission. The AMS will provide information of the cloud cover in the FoV of JEM-EUSO, as well as measurements of the cloud top altitudes with an accuracy of 500 m and the optical depth profile of the atmosphere transmittance in the direction of each air shower with an accuracy of 0.15 degree and a resolution of 500 m. This will ensure that the energy of the primary UHECR and the depth of maximum development of the EAS ( Extensive Air Shower) are measured with an accuracy better than 30\% primary energy and 120 $g/cm^2$ depth of maximum development for EAS occurring either in clear sky or with the EAS depth of maximum development above optically thick cloud layers. Moreover a very novel radiometric retrieval technique considering the LIDAR shots as calibration points, that seems to be the most promising retrieval algorithm is under development to infer the Cloud Top Height (CTH) of all kind of clouds, thick and thin clouds in the FoV of the JEM-EUSO space telescope.

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arXiv2014

AtmoHEAD 2013 workshop / Atmospheric Monitoring for High-Energy Astroparticle Detectors

A 3-day international workshop on atmospheric monitoring and calibration for high-energy astroparticle detectors, with a view towards next-generation facilities. The atmosphere is an integral component of many high-energy astroparticle detectors. Imaging atmospheric Cherenkov telescopes and cosmic-ray extensive air shower detectors are the two instruments driving the rapidly evolving fields of very-high- and ultra-high-energy astrophysics. In these instruments, the atmosphere is used as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate EASs; it is also the medium through which the resulting Cherenkov light propagates. Uncertainties in real-time atmospheric conditions and in the fixed atmospheric models typically dominate all other systematic errors. With the improved sensitivity of upgraded IACTs such as H.E.S.S.-II and MAGIC-II and future facilities like the Cherenkov Telescope Array (CTA) and JEM-EUSO, statistical uncertainties are expected to be significantly reduced, leaving the atmosphere as the limiting factor in the determination of astroparticle spectra. Varying weather conditions necessitate the development of suitable atmospheric monitoring to be integrated in the overall instrument calibration, including Monte Carlo simulations. With expertise distributed across multiple collaborations and scientific domains, an interdisciplinary workshop is being convened to advance progress on this critical and timely topic.

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arXiv2014

The Atmospheric Monitoring system of the JEM-EUSO telescope

The JEM-EUSO observatory on board of the International Space Station (ISS) is a proposed pioneering space mission devoted to the investigation of Ultra High Energy Cosmic Rays (UHECRs). Looking downward at the earth's atmosphere with a 60$^\circ$ Field of View (FoV), the JEM-EUSO telescope will detect the fluorescence and Cherenkov UV emission from UHECR induced Extensive Air Showers (EAS) penetrating in the atmosphere. The capability of reconstructing the properties of the primary cosmic ray depends on the accurate measurement of the atmospheric conditions in the region of EAS development. The Atmospheric Monitoring system of JEM-EUSO will continuously monitor the atmosphere at the location of the EAS candidates and between the EAS and the JEM-EUSO telescope. With an UV LIDAR and an Infrared (IR) Camera the system will monitor the cloud cover and retrieve the cloud top altitude with an accuracy of $\sim$ 500 m and the optical depth profile of the atmosphere with an accuracy of $Δτ\leq$ 0.15 and a resolution of 500 m. In this contribution the Atmospheric Monitoring system of JEM-EUSO will be presented. After a brief description of the system, the capability to recover the cloud top height and optical depth and to reconstruct the shower profile will be shown based on satellites data and simulation studies.

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arXiv2011

Observation of Anisotropy in the Arrival Direction Distribution of Cosmic Rays above TeV Energies with Icecube

Between May 2009 and May 2010, the IceCube neutrino detector recorded 32 billion of atmospheric muons generated in air showers produced by cosmic rays in the TeV energy range. With such high statistics sample it is possible to observe, for the first time in the southern hemisphere, an energy dependence in the Galactic cosmic ray anisotropy up to a few hundred TeV. This study shows that the same large-scale anisotropy observed at median energies around 20 TeV is not present at 400 TeV; the anisotropy observed at 400 TeV shows substantial differences with respect to that at lower energy. In addition to the large-scale features observed at 20 TeV in the form of strong dipole and quadrupole moments, the data include several localized regions of excess and deficit on scales between 10{\degree} to 30{\degree}. The features observed at both large and small scale are statistically significant, but their origin is currently unknown.

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arXiv2010

Observation of the anisotropy in arrival direction of Cosmic Rays with IceCube

The IceCube Neutrino Observatory is a kilometer-scale detector currently under construction at the South Pole. In its final configuration the detector will comprise 5160 Digital Optical Modules (DOMs) deployed on 86 strings between 1.5-2.5 km deep within the ice. While still incomplete, the detector has already recorded tens of billions of cosmic ray muons with a median energy of 20 TeV. This large sample has been used to study the arrival direction distribution of the cosmic rays. We report the observation of an anisotropy in the cosmic rays arrival direction at two different angular scales. The observed large scale anisotropy seems to be a continuation of similar structures observed in the Northern Sky by several experiments. IceCube observes also significant features on the angular scale of $20^{\circ} - 30^{\circ}$ that might be part of the larger scale structure.

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arXiv2007

Millimeter observations of Planetary Nebulae: a contribution to the Planck pre-launch catalogue

We present new millimetre 43 GHz observations of a sample of radio-bright Planetary Nebulae. Such observations were carried out to have a good determination of the high-frequency radio spectra of the sample in order to evaluate, together with far-IR measurements (IRAS), the fluxes emitted by the selected source in the millimetre and sub-millimetre band. This spectral range, even very important to constraint the physics of circumstellar environment, is still far to be completely exploited. To estimate the millimetre and sub-millimetre fluxes, we extrapolated and summed together the ionized gas (free-free radio emission) and dust (thermal emission) contributions at this frequency range. By comparison of the derived flux densities to the foreseen sensitivity we investigate the possible detection of such source for all the channels of the forthcoming ESA's PLANCK mission. We conclude that almost 80% of our sample will be detected by PLANCK, with the higher detection rate in the higher frequency channels, where there is a good combination of brighter intrinsic flux from the sources and reduced extended Galactic foregrounds contamination despite a worst instrumental sensitivity. From the new 43 GHz, combined with single-dish 5 GHz observations from the literature, we derive radio spectral indexes, which are consistent with optically thin free-free nebula. This result indicates that the high frequency radio spectrum of our sample sources is dominated by thermal free-free and other emission, if present, are negligible.

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