We employ neural networks for classification of data of the TUS fluorescence telescope, the world’s first orbital detector of ultra-high energy cosmic rays. We focus on two particular types of ...signals in the TUS data: track-like flashes produced by cosmic ray hits of the photodetector and flashes that originated from distant lightnings. We demonstrate that even simple neural networks combined with certain conventional methods of data analysis can be highly effective in tasks of classification of data of fluorescence telescopes.
The orbital detector TUS (Tracking Ultraviolet Setup) with high sensitivity in near-visible ultraviolet (tens of photons per time sample of 0.8 μ s of wavelengths 300–400 nm from a detector’s pixel ...field of view) and the microsecond-scale temporal resolution was developed by the Lomonosov-UHECR/TLE collaboration and launched into orbit on 28 April 2016. A variety of different phenomena were studied by measuring ultraviolet signals from the atmosphere: extensive air showers from ultra-high-energy cosmic rays, lightning discharges, transient atmospheric events, aurora ovals, and meteors. These events are different in their origin and in their duration and luminosity. The TUS detector had a capability to conduct measurements with different temporal resolutions (0.8 μ s, 25.6 μ s, 0.4 ms, and 6.6 ms) but the same spatial resolution of 5 km. Results of the TUS detector measurements of various atmospheric emissions are discussed and compared to data from previous experiments.
Monitoring of someone’s behavior is accompanied by integrating the results of another person’s cognitive activity into our own. We assumed that the process of such integration occurs involuntarily ...and automatically. The subjects watched “silent” video clips, where the character looked beyond the frame and demonstrated a behavior, pointing that he recognized an object of a certain category at the end of the video. Then the subjects observed the scene from the character’s perspective, demonstrating what he or she saw. The subjects’ task was to find a visually noticeable letter on these frames as quickly as possible. Healthy individuals (N=70) and patients with schizophrenia (N=34) took part in the study. The healthy subjects who observed the character’s behavior automatically analyzed the object perceived by the character, and only after that they searched for the target letter, in contrast to healthy participants who did not see the observer’s behavior. Patients with schizophrenia who understood the character’s behavior, in contrast to patients who did not, first of all analyzed the object perceived by the character and spent more time detecting the target letter. The study showed that integrating cognitions with observed person is a principally automatic process.
Работа направлена на проверку гипотезы о том, что при наблюдении за поведением другого человека люди непроизвольно, автоматически интегрируют результаты его когнитивной активности в собственную когнитивную активность. Разработана процедура: испытуемые просматривали «немые» видеосюжеты; в конце персонаж, смотря за пределы кадра, демонстрировал реакцию, свидетельствующую, что он воспринял объект определенной категории. После фиксационного креста испытуемые наблюдали кадры, с перспективы персонажа показывающие, что он увидел. Задачей испытуемых было как можно быстрее найти на этих кадрах визуально заметную букву. Были обследованы здоровые лица (N=70) и больные шизофренией (N=34). Здоровые лица, наблюдавшие поведение персонажа, в отличие от здоровых лиц, его не наблюдавших, непроизвольно анализировали объект, воспринятый персонажем, и лишь после этого искали целевую букву. Больные, понявшие поведение персонажа, в отличие от больных, его не понявших, в первую очередь также анализировали объект, воспринятый персонажем, вследствие чего дольше искали целевую букву. Исследование показало, что в условиях наблюдения за другим человеком процесс интеграции результатов его когнитивной активности в собственную является преимущественно автоматическим процессом.
KLYPVE-EUSO (K-EUSO) is a planned orbital detector of ultra-high energy cosmic rays (UHECRs), which is to be deployed on board the International Space Station. K-EUSO is expected to have a uniform ...exposure over the celestial sphere and register from 120 to 500 UHECRs at energies above 57 EeV in a 2-year mission. We employed the TransportCR and CRPropa 3 packages to estimate prospects of testing a minimal single source class model for extragalactic cosmic rays and neutrinos by Kachelrieß, Kalashev, Ostapchenko and Semikoz (2017) with K-EUSO in terms of the large-scale anisotropy. Nearby active galactic nuclei Centaurus A, M82, NGC 253, M87 and Fornax A were considered as possible sources of UHECRs. We demonstrate that an observation of more than 200 events will allow testing predictions of the model with a high confidence level providing the fraction of events arriving from any of the sources is ^10-15%, with a smaller contribution for larger samples. These numbers agree with theoretical expectations of a possible contribution of a single source in the UHECR flux. Thus, K-EUSO can provide good opportunities for verifying the minimal model basing on an analysis of the large-scale anisotropy of arrival directions of UHECRs.
K-EUSO (KLYPVE-EUSO) is a planned orbital mission aimed at studying ultra-high energy cosmic rays (UHECRs) by detecting fluorescence and Cherenkov light emitted by extensive air showers in the ...nocturnal atmosphere of Earth in the ultraviolet (UV) range. The observatory is being developed within the JEM-EUSO collaboration and is planned to be deployed on the International Space Station after 2025 and operated for at least two years. The telescope, consisting of ∼105 independent pixels, will allow a spatial resolution of ∼0.6 km on the ground, and, from a 400 km altitude, it will achieve a large and full sky exposure to sample the highest energy range of the UHECR spectrum. We provide a comprehensive review of the current status of the development of the K-EUSO experiment, paying special attention to its hardware parts and expected performance. We demonstrate how results of the K-EUSO mission can complement the achievements of the existing ground-based experiments and push forward the intriguing studies of ultra-high energy cosmic rays, as well as bring new knowledge about other phenomena manifesting themselves in the atmosphere in the UV range.
The Tracking Ultraviolet Setup (TUS) detector was launched on April 28, 2016 as a part of the scientific payload of the Lomonosov satellite. TUS is a pathfinder mission for future space-based ...observation of Extreme-Energy Cosmic Rays (EECRs, E > 5x10
19
eV) with experiments such as K-EUSO. TUS data offer the opportunity to develop strategies in the analysis and reconstruction of the events which will be essential for future space-based missions. During its operation, TUS has detected about 80 thousand events which have been subject to an offline analysis to select among them those that satisfy basic temporal and spatial criteria of EECRs. A few events passed this first screening. In order to perform a deeper analysis of such candidates, a dedicated version of ESAF (EUSO Simulation and Analysis Framework) code as well as a detailed modelling of TUS optics and detector are being developed.
Abstract
The problem of identification of ultra-high-energy cosmic ray (UHECR) sources is greatly complicated by the fact that even the highest energy cosmic rays may be deflected by tens of degrees ...in the galactic magnetic fields. We show that arrival directions of UHECRs from several nearest active galaxies form specific patterns in the sky, which can be effectively recognized by convolutional neural networks. We use one of the recently developed convnet implementations for images defined on the sphere to train the classifier that is able to detect patterns that can be present in the experimental data. We calculate the minimal detectable from-source event fractions for several realistic source candidates and discuss the method limitations.
The Tracking Ultraviolet Setup (TUS) was the first orbital detector aimed to check the possibility of recording ultra-high energy cosmic rays (UHECRs) at E≳100 EeV by measuring the fluorescence ...signal of extensive air showers in the atmosphere. TUS was an experiment funded by the Russian Space Agency ROSCOSMOS, and it operated as a part of the scientific payload of the Lomonosov satellite since April 2016 till late 2017. During its mission, TUS registered almost 80,000 events in its main operation mode, with a few of them being sufficiently interesting to be more deeply scrutinized as they showed light profile and duration similar to UHECR events, even though much brighter. At the same time, the data acquired by TUS in different acquisition modes have been used to search for more exotic matter such us strangelets and nuclearites, and to measure occurrence, time profile and signal amplitude of different classes of transient luminous events among other scientific objectives, showing the interdisciplinary capability of a space-based observatory for UHECRs. In this paper, we report a selection of studies and results obtained with the TUS telescope which will be presented and placed in the contest of the present and future missions dedicated to the observation of UHECRs from space such as Mini-EUSO, K-EUSO and POEMMA.
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