Improving photon-hadron discrimination based on cosmic ray surface detector data

The search for photons at EeV energies and beyond has considerable astrophysical interest and will remain one of the key challenges for ultra-high energy cosmic ray (UHECR) observatories in the near future. Several upper limits to the photon flux have been established since no photon has been unambiguously observed up to now. An improvement in the reconstruction efficiency of the photon showers and/or better discrimination tools are needed to improve these limits apart from an increase in statistics. Following this direction, we analyze in this work the ability of the surface parameter Sb, originally proposed for hadron discrimination, for photon search. Semi-analytical and numerical studies are performed in order to optimize Sb for the discrimination of photons from a proton background in the energy range from 10^18.5 to 10^19.6 eV. Although not shown explicitly, the same analysis has been performed for Fe nuclei and the corresponding results are discussed when appropriate. The effects of different array geometries and the underestimation of the muon component in the shower simulations are analyzed, as well as the Sb dependence on primary energy and zenith angle.Comment: 9 pages, 19 Figures. Accepted in Astroparticle Physics on May 31th, 201

The Atmospheric Monitoring System of the JEM-EUSO Space Mission

An Atmospheric Monitoring System (AMS) is a mandatory and key device of a space-based mission which aims to detect Ultra-High Energy Cosmic Rays (UHECR) and Extremely-High Energy Cosmic Rays (EHECR) from Space. JEM-EUSO has a dedicated atmospheric monitoring system that plays a fundamental role in our understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. Our AMS consists of a very challenging space infrared camera and a LIDAR device, that are being fully designed with space qualification to fulfil the scientific requirements of this space mission. The AMS will provide information of the cloud cover in the FoV of JEM-EUSO, as well as measurements of the cloud top altitudes with an accuracy of 500 m and the optical depth profile of the atmosphere transmittance in the direction of each air shower with an accuracy of 0.15 degree and a resolution of 500 m. This will ensure that the energy of the primary UHECR and the depth of maximum development of the EAS ( Extensive Air Shower) are measured with an accuracy better than 30\% primary energy and 120 $g/cm^2$ depth of maximum development for EAS occurring either in clear sky or with the EAS depth of maximum development above optically thick cloud layers. Moreover a very novel radiometric retrieval technique considering the LIDAR shots as calibration points, that seems to be the most promising retrieval algorithm is under development to infer the Cloud Top Height (CTH) of all kind of clouds, thick and thin clouds in the FoV of the JEM-EUSO space telescope

Thin and thick cloud top height retrieval algorithm with the Infrared Camera and LIDAR of the JEM-EUSO Space Mission

The origin of cosmic rays have remained a mistery for more than a century. JEM-EUSO is a pioneer space-based telescope that will be located at the International Space Station (ISS) and its aim is to detect Ultra High Energy Cosmic Rays (UHECR) and Extremely High Energy Cosmic Rays (EHECR) by observing the atmosphere. Unlike ground-based telescopes, JEM-EUSO will observe from upwards, and therefore, for a properly UHECR reconstruction under cloudy conditions, a key element of JEM-EUSO is an Atmospheric Monitoring System (AMS). This AMS consists of a space qualified bi-spectral Infrared Camera, that will provide the cloud coverage and cloud top height in the JEM-EUSO Field of View (FoV) and a LIDAR, that will measure the atmospheric optical depth in the direction it has been shot. In this paper we will explain the effects of clouds for the determination of the UHECR arrival direction. Moreover, since the cloud top height retrieval is crucial to analyze the UHECR and EHECR events under cloudy conditions, the retrieval algorithm that fulfills the technical requierements of the Infrared Camera of JEM-EUSO to reconstruct the cloud top height is presently reported.Comment: 5 pages, 6 figures, Atmohead Conference 201

A new composition-sensitive parameter for Ultra-High Energy Cosmic Rays

A new family of parameters intended for composition studies in cosmic ray surface array detectors is proposed. The application of this technique to different array layout designs has been analyzed. The parameters make exclusive use of surface data combining the information from the total signal at each triggered detector and the array geometry. They are sensitive to the combined effects of the different muon and electromagnetic components on the lateral distribution function of proton and iron initiated showers at any given primary energy. Analytical and numerical studies have been performed in order to assess the reliability, stability and optimization of these parameters. Experimental uncertainties, the underestimation of the muon component in the shower simulation codes, intrinsic fluctuations and reconstruction errors are considered and discussed in a quantitative way. The potential discrimination power of these parameters, under realistic experimental conditions, is compared on a simplified, albeit quantitative way, with that expected from other surface and fluorescence estimators.Comment: 27 pages, 17 figures. Submitted to a refereed journa

PrevenBox: Evaluation of concomitant use of preventive medications with OnabotulinumtoxinA in migraine

P114 Background: OnabotulinumtoxinA is an effective, tolerable and safepreventive treatment for chronic migraine (CM). Other than a reduc-tion in headache frequency or disability, in CM the withdrawal ofconcomitant preventive medication indicates treatment effectivenessand quality of life improvement. Objective: To characterize the change in the use of oral preventivemedication after treatment with OnabotulinumtoxinA in patientswith migraine. Methods: This is a multicentre study. We consecutively included pa-tients with migraine (ICHD-3) that were on preventive treatment withOnabotulinumtoxinA. We retrospectively collected demographic data, diagnosis of migraine, frequency and intensity changes, number ofcycle and OnabotulinumtoxinA dose. In addition, we listed the initialand current preventive treatment (number of drugs and group) andthe number and cycle of medications withdrawn. We performed aunivariate and logistic regression analysis. Results: We included 542 patients: 87.6% women, mean age 47.6 ±11.7 years. A 89.3% had chronic migraine and 10.8% had high fre-quency episodic migraine. The mean reduction in frequency aftertreatment was 13.4±8.2 headache days/month. At baseline, a 91.3%took other preventives and during treatment with Onabotulinumtox-inA a 58.6% withdrew at least one drug, 25.8% stopped completelyall oral preventive drugs. Factors associated with withdrawal were:being male, having >50% response in frequency and intensity, thenumber of infiltrations and a shorter chronification period until thefirst OnabotulinumtoxinA administration (p <0.05). The multivariateanalysis showed that a better response in intensity (OR:1.8 [1.4-2.2], p<0.001), a greater number of infiltrations (OR:1.1 [1.0-1.2], p<0.001)and a shorter chronification period (OR:0.994 [0.992-0.997], p<0.001)were predictors of withdrawal. The ROC curve, showed that 6 Onabo-tulinumtoxinA cycles was the cut-off point that better predicted oralpreventive medication withdrawal (p <0.001). Conclusions: Treatment with OnabotulinumtoxinA reduces the use ofother preventive medications for migraine. The highest probability ofwithdrawal occurs after 6 cycles of treatment

Obtaining cloud top height from WRF model vertical profiles: application to the EUSO program

The objective of the Extreme Universe Space Observatory (EUSO) program is detection and measurement of high-energy particles that reach earth?s atmosphere from space. Clouds at mid and upper levels of the troposphere can interfere with such detection. Therefore, determining cloud top height with high accuracy is crucial to estimating the effect of clouds on these measurements.With this aim, we developed a method to extract that height using cloud temperature via vertical profiles predicted by the WRF model

The Spanish Infrared Camera onboard the EUSO-BALLOON (CNES) flight on August 24, 2014

The EUSO-Balloon (CNES) campaign was held during Summer 2014 with a launch on August 24. In the gondola, next to the Photo Detector Module (PDM), a completely isolated Infrared camera was allocated. Also, a helicopter which shooted flashers flew below the balloon. We have retrieved the Cloud Top Height (CTH) with the IR camera, and also the optical depth of the nonclear atmosphere have been inferred with two approaches: The first one is with the comparison of the brightness temperature of the cloud and the real temperature obtained after the pertinent corrections. The second one is by measuring the detected signal from the helicopter flashers by the IR Camera, considering the energy of the flashers and the location of the helicopter