0000000000352251
AUTHOR
Francesco Longo
Enhanced detection of terrestrial gamma-ray flashes by AGILE
At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter instrument. The motivation for such a change was the understanding that the dead time induced by the anticoincidence prevented the detection of a large fraction of Terrestrial Gamma-Ray Flashes (TGFs). The configuration change was highly successful resulting in an increase of one order of magnitude in TGF detection rate. As expected, the largest fraction of the new events has short duration (<100 μs), and part of them has simultaneous association with lightning sfer…
Machine Learning approach towards real time assessment of hand-arm vibration risk
Abstract In industry 4,0, the establishment of an interconnected environment where human operators cooperate with the machines offers the opportunity for substantially improving the ergonomics and safety conditions of the workplace. This topic is discussed in the paper referring to the vibration risk, which is a well-known cause of work-related pathologies. A wearable device has been developed to collect vibration data and to segment the signals obtained in time windows. A machine learning classifier is then proposed to recognize the worker’s activity and to evaluate the exposure to vibration risks. The experimental results demonstrate the feasibility and effectiveness of the methodology pr…
Note preliminari sul rinvenimento di un'area artigianale da Contrada Amone e sulla produzione ceramica nel bacino idrografico del fiume Nocella
Questo articolo esamina le evidenza archeologiche di età romana nella Piana di Partinico, un'area ad Est del Golfo di Castellammare ricca di insediamenti rurali e ville tra cui quella famosa di Sirignano. L'area di contrada Amone, già nota per la presenza di un impianto termale e la scoperta di lacerti di mosaici policromi, si arricchisce adesso di una nuova area artigianale. La scoperta di alcuni scarti di tegole ha fornito l'opportunità per riflettere sulla possibile origine delle tegole bollate ONASOY, di cui si accetta tradizionalmente la provenienza dalla baia di San Cataldo. Viene dunque presentato un esame preliminare degli impasti ceramici provenienti da contrada Amone e baia San Ca…
Multiband variability studies and novel broadband SED modeling of Mrk 501 in 2009
Astronomy and astrophysics 603, A31 (2017). doi:10.1051/0004-6361/201629540
The Large Observatory For x-ray Timing
The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideFi…
First Multi-wavelength Campaign on the Gamma-ray-loud Active Galaxy IC 310
The extragalactic VHE gamma-ray sky is rich in blazars. These are jetted active galactic nuclei viewed at a small angle to the line-of-sight. Only a handful of objects viewed at a larger angle are known so far to emit above 100 GeV. Multi-wavelength studies of such objects up to the highest energies provide new insights into the particle and radiation processes of active galactic nuclei. We report the results from the first multi-wavelength campaign observing the TeV detected nucleus of the active galaxy IC 310, whose jet is observed at a moderate viewing angle of 10 deg - 20 deg. The multi-instrument campaign was conducted between 2012 Nov. and 2013 Jan., and involved observations with MAG…
Observatory science with eXTP
Disponible preprint en: arXiv:1812.04023v1 [astro-ph.HE] [v1] Mon, 10 Dec 2018 19:00:52 UTC (4,376 KB)
Black hole lightning due to particle acceleration at subhorizon scales
Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20\% of the gravitational radius of its central black hole. We suggest that the emission is associated …
Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
Full list of authors: EHT MWL Science Working Group; Algaba, J. C.; Anczarski, J.; Asada, K.; Baloković, M.; Chandra, S.; Cui, Y. -Z.; Falcone, A. D.; Giroletti, M.; Goddi, C.; Hada, K.; Haggard, D.; Jorstad, S.; Kaur, A.; Kawashima, T.; Keating, G.; Kim, J. -Y.; Kino, M.; Komossa, S.; Kravchenko, E. V.; Krichbaum, T. P.; Lee, S. -S.; Lu, R. -S.; Lucchini, M.; Markoff, S.; Neilsen, J.; Nowak, M. A.; Park, J.; Principe, G.; Ramakrishnan, V.; Reynolds, M. T.; Sasada, M.; Savchenko, S. S.; Williamson, K. E.; Event Horizon Telescope Collaboration; Akiyama, Kazunori; Alberdi, Antxon; Alef, Walter; Anantua, Richard; Azulay, Rebecca; Baczko, Anne-Kathrin; Ball, David; Barrett, John; Bintley, Dan; …
Coincidence of a high-fluence blazar outburst with a PeV-energy neutrino event
The discovery of extraterrestrial very-high-energy neutrinos by the IceCube collaboration has launched a quest for the identification of their astrophysical sources. Gamma-ray blazars have been predicted to yield a cumulative neutrino signal exceeding the atmospheric background above energies of 100 TeV, assuming that both the neutrinos and the gamma-ray photons are produced by accelerated protons in relativistic jets. Since the background spectrum falls steeply with increasing energy, the individual events with the clearest signature of being of an extraterrestrial origin are those at PeV energies. Inside the large positional-uncertainty fields of the first two PeV neutrinos detected by Ic…
Machine Learning approach towards real time assessment of hand-arm vibration risk
In industry 4,0, the establishment of an interconnected environment where human operators cooperate with the machines offers the opportunity for substantially improving the ergonomics and safety conditions of the workplace. This topic is discussed in the paper referring to the vibration risk, which is a well-known cause of work-related pathologies. A wearable device has been developed to collect vibration data and to segment the signals obtained in time windows. A machine learning classifier is then proposed to recognize the worker’s activity and to evaluate the exposure to vibration risks. The experimental results demonstrate the feasibility and effectiveness of the methodology proposed.
The THESEUS space mission concept: science case, design and expected performances
THESEUS is a space mission concept aimed at exploiting Gamma-Ray Bursts for investigating the early Universe and at providing a substantial advancement of multi-messenger and time-domain astrophysics. These goals will be achieved through a unique combination of instruments allowing GRB and X-ray transient detection over a broad field of view (more than 1sr) with 0.5¿1 arcmin localization, an energy band extending from several MeV down to 0.3¿keV and high sensitivity to transient sources in the soft X-ray domain, as well as on-board prompt (few minutes) follow-up with a 0.7¿m class IR telescope with both imaging and spectroscopic capabilities. THESEUS will be perfectly suited for addressing …