G. Sáez Cano

Observation of ultra-high energy cosmic rays in cloudy conditions by the space-based JEM-EUSO Observatory

JEM-EUSO is a space observatory that will be located on-board the Japanese Experiment Module at the International Space Station. It will observe Extensive Air Showers (EAS) induced by ultra-high energy cosmic rays using the Earths atmosphere as detector. In addition to clear sky observations, EAS are also observable in cloudy conditions if a sufficiently large part of the EAS development occurs above the cloud. The atmospheric monitoring system plays a fundamental role in our understanding of the atmospheric conditions in the field of view of the telescope.

Observation of Ultra-High Energy Cosmic Rays in cloudy conditions by the JEM-EUSO Space Observatory

Source of Ultra-high Energy Cosmic Rays (several times 10 19 eV) are still unidentified. Overcoming their extremely small fluxes, a detector with huge observation are as is needed to investigate the energy and arrival direction distribution of EECRs. JEM-EUSO is a unique experiment that will be located in the International Space Station to observe extensive air showers (EAS) by monitoring night part of Earth atmosphere. In addition to clear sky condition, the extensive air showers in cloudy condition are also observable by taking advantage of the certain fraction of EAS develop above the cloud. In the preset work, using Monte Carlo simultions for test clouds, the cloud impact to the trigger efficiency was estimated taking into account the statistics of cloud property.

Cloud Optical Depth obtained from the Infrared Camera data and the UV Flashers mounted on a helicopter flying under the EUSO

Spain. 2 ISDC, Astronomy Dept. University of Geneva, Switzerland. 3 University of Alabama in Huntsville (UAH), Huntsville, USA. 4 Colorado School of Mines, Golden, USA. 5 GFA. IMA. University of León, León, Spain. 6 Instituto de Astrofísica de Canarias (IAC), Vía Lactea S/N, Tenerife, Spain. 7 IDR/UPM, E. T. S. I. Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Spain. 8 IFIC, CSIC, U. de València. Dpto. Física Atómica, Molecular y Nuclear, U. de València, Spain.