Marián Putiš

Night time measurement of the UV background by EUSO-Balloon

Š. Mackovjak∗1, A. Neronov1, P. Bobík2, M. Putiš2, L. Del Peral1, 3, M. D. Rodríguez Frías1, 3, 8, K. Shinozaki4, C. Catalano5, J. F. Soriano3, G. Sáez-Cano3, C. Moretto6, S. Bacholle7 for the JEM-EUSO Collaboration 1 ISDC Data Centre for Astrophysics, University of Geneva, Switzerland 2 Department of Space Physics, IEP, Slovak Academy of Sciences, Košice, Slovakia 3 SPace & AStroparticle (SPAS) Group, UAH, Madrid, Spain 4 Institute for Astronomy and Astrophysics, University of Tübingen, Germany 5 Institut de Recherche en Astrophysique et Planétologie, CNRS-UPS Toulouse, France 6 Laboratoire de l’Accélérateur Linéaire, Université Paris Sud, France 7 Laboratoire AstroParticule et Cosmologie, Université Paris Diderot, France 8 IFIC, CSIC, Dpto. Física Atómica, Molecular y Nuclear, Universitat de València, Spain

Pattern recognition study for different levels of UV background in JEM-EUSO experiment

JEM-EUSO experiment will observe UV light created by extensive air showers initiated by ultra high energy cosmic rays (UHECR). Reconstruction of UHECR particle direction from detected signal depends also on the level of signal background, which can vary in time and with location. We developed an alternative pattern recognition (PR) method based on Hough transforms besides to existing PR methods in JEM-EUSO software framework. The results of PWISE method and Hough method were compared for the standard (nominal) UV background 500ph/(m2.ns.sr). Hough method was used to evaluation of UHECR direction reconstruction ability for higher level of UV backgrounds on the Earth’s night side. The study on the impact of varying the background level on the fake trigger event rate was performed as well.

Method for analysis of the effect of geomagnetic disturbances on UV airglow intensity

Airglow is a dynamic phenomenon which depends on the geographical location, season, local time, geomagnetic activity, and other conditions. Variations in UV nighttime airglow (300–500 nm) caused by magnetospheric disturbances for several selected points around globe are presented in this study. Used airglow intensity data were evaluated in empirical model Atmospheric Ultraviolet Radiance Integrated Code. We focus on points around the auroral oval position for very disturbed magnetosphere (Kp = 8) and positions chosen for the Airglow MONitor network. This network will consist of a set of small one pixel detectors, designed for long time measurements. A simple statistical method was developed for long time data analysis of geomagnetic disturbances of airglow. Results of the method for planned stations are presented.

Implications for space-based UHECR observation from UV background light measurements by JEM-EUSO pathfinders

EUSO (Extreme Universe Space Observatory) is a next-generation space-based UHECR observation concept to detect extensive air shower events by the fluorescence technique. The determination of the exposure for UHECR observations is essential to reach the scientific objectives. It involves trigger efficiency, observational duty cycle, impacts of clouds etc. UV light from the terrestrial and extraterrestrial sources is a major background for UHECR observations. It includes man-made light, airglow emission starlight, moonlight, zodiacal light etc. In the EUSO pathfinder missions, we carried out the measurements of the UV light by operating a prototype 1~m square refractive Fresnel telescope with a photo-detector module on balloons and on the ground. So far, flights of EUSO-Balloon and EUSO-SPB~(Supper Pressure Balloon) achieved 1- and 12-night flights in Canada and south Pacific, respectively. Using different optics, two satellite-borne pathfinders, TUS~(Tracking Ultraviolet Set-up) has been operational and Mini-EUSO are currently scheduled. On the ground EUSO-TA has been operational at the Telescope Array experiment site. All the pathfinders are designed to measure UV light to provide a larger amount of data in various conditions. In the present contribution, the basic concept to establish a scheme to determine the exposure for space-based UHECRs is discussed. A part of results from EUSO-Balloon about the background light measurements relevant to the exposure determination are presented. We also intrdouce an outlook for further studies by EUSO-SPB, TUS and Mini-EUSO.

An analytically iterative method for solving problems of cosmic-ray modulation

The development of an analytically iterative method for solving steady-state as well as unsteady-state problems of cosmic-ray (CR) modulation is proposed. Iterations for obtaining the solutions are constructed for the spherically symmetric form of the CR propagation equation. The main solution of the considered problem consists of the zero-order solution that is obtained during the initial iteration and amendments that may be obtained by subsequent iterations. The finding of the zero-order solution is based on the CR isotropy during propagation in the space, whereas the anisotropy is taken into account when finding the next amendments. To begin with, the method is applied to solve the problem of CR modulation where the diffusion coefficient

Feature Extraction Methods in JEM-EUSO Experiment

\kappa

Performance and air-shower reconstruction techniques for the JEM-EUSO mission

and the solar wind speed

Airglow dynamics observations by Mini-EUSO

u

Evaluation of scientific performance of JEM-EUSO mission with Space-X Dragon option

are constants with an Local Interstellar Spectra (LIS) spectrum. The solution obtained with two iterations was compared with an analytical solution and with numerical solutions. Finally, solutions that have only one iteration for two problems of CR modulation with

Modelling muon and neutron fluxes and spectra on the Earth's ground induced by primary cosmic rays

u = constant