Speaker
Simon Mackovjak
(ISDC - Data Centre for Astrophysics, Astronomy Department, University of Geneva, Switzerland)
Description
Precise characterization of the Earth night side UV background is essential for observation of the ultra-high-energy cosmic ray induced extensive air showers (EAS) from the space. We have analyzed data from the flight of EUSO-Balloon pathfinder mission that took place near Timmins (Canada) in the moonless night from 24$^{th}$ to 25$^{th}$ August 2014. The EUSO-balloon telescope imaged the UV background in the wavelength range 290--430 nm from the altitude $\sim$38 km with a 1 m$^2$ refractor telescope with $11.5^\circ$ field-of-view pointed in nadir direction. The UV data were complemented by the data of the Infrared (IR) camera onboard EUSO-balloon, which operated in the wavelength ranges 10.37--11.22 $\mu$m and 11.57--12.42 $\mu$m. We have combined the UV and IR images to study the upward UV radiance from the Earth surface and Earth atmosphere. This allowed us to estimate UV background in clear atmosphere conditions without man-made lights and also to investigate influence of clouds on the UV background values. The obtained UV intensity for clear atmosphere conditions is in a good agreement with previous BaBy and NIGHTGLOW balloon measurements. Comparison of the UV and IR images reveals a strong dependence of the upward UV radiance on the atmospheric conditions, so we discuss the possibility to use the UV albedo effect for characterization of the clouds. For estimating the observation efficiency of EAS from space by EUSO like detectors, it is important to determine the time variation of average UV background intensity, cloud distribution and local man-made light. Using available data, we also discuss these key factors that determine the observable time and area for EAS observation.
| Registration number following "ICRC2015-I/" | 689 |
|---|---|
| Collaboration | JEM-EUSO |
Primary author
Simon Mackovjak
(ISDC - Data Centre for Astrophysics, Astronomy Department, University of Geneva, Switzerland)
Co-authors
Andrii Neronov
(ISDC - Data Centre for Astrophysics, Astronomy Department, University of Geneva, Switzerland)
Camille Catalano
(Institut de Recherche en Astrophysique et Planétologie, CNRS-UPS Toulouse, France)
Camille Moretto
(Laboratoire de l'Accélérateur Linéaire, Université Paris Sud, France)
Guadalupe Sáez Cano
(Space and Astroparticle Group, University of Alcalá, Spain)
Jorge Fernández Soriano
(Space and Astroparticle Group, University of Alcalá, Spain)
Kenji Shinozaki
(Institute for Astronomy and Astrophysics, University of Tübingen, Germany)
Luis Del Peral
(Space and Astroparticle Group, University of Alcalá, Spain)
Maria Rodriguez Frias
(Space and Astroparticle Group, University of Alcalá, Spain)
Marian Putiš
(Department of Space Physics, Institute of Experimental Physics, Slovak Academy of Science, Slovakia)
Pavol Bobík
(Department of Space Physics, Institute of Experimental Physics, Slovak Academy of Science, Slovakia)
Simon Bacholle
(Laboratoire AstroParticule et Cosmologie, Université Paris Diderot, France)
