0000000000102840
AUTHOR
G La Rosa
ESTREMO/WFXRT: Extreme phySics in the TRansient and Evolving COsmos
We present a mission designed to address two main themes of the ESA Cosmic Vision Programme: the Evolution of the Universe and its Violent phenomena. ESTREMO/WFXRT is based on innovative instrumental and observational approaches, out of the mainstream of observatories of progressively increasing area, i.e.: Observing with fast reaction transient sources, like GRB, at their brightest levels, thus allowing high resolution spectroscopy. Observing and surveying through a X-ray telescope with a wide field of view and with high sensitivity extended sources, like cluster and Warm Hot Intragalactic Medium (WHIM). ESTREMO/WFXRT will rely on two cosmological probes: GRB and large scale X-ray structur…
The Pierre Auger Observatory scaler mode for the study of solar activity modulation of galactic cosmic rays
Since data-taking began in January 2004, the Pierre Auger Observatory has been recording the count rates of low energy secondary cosmic ray particles for the self-calibration of the ground detectors of its surface detector array. After correcting for atmospheric effects, modulations of galactic cosmic rays due to solar activity and transient events are observed. Temporal variations related with the activity of the heliosphere can be determined with high accuracy due to the high total count rates. In this study, the available data are presented together with an analysis focused on the observation of Forbush decreases, where a strong correlation with neutron monitor data is found.
A popliteal artery aneurysm presenting with ab extrinseco popliteal vein occlusion and compartment syndrome
INTRODUCTION: Aneurysms of popliteal artery are the most frequently reported aneurysm after abdominal aorta. An unusual presentation is compression to adjacent structure. CASE PRESENTATION: A 67 years old caucasian man presenting deep vein thrombosis signs to the right leg including functional impotence was admitted in emergency setting to Vascular Surgery Unit. A pulsing mass was present in the popliteal cave at inspection. The computed tomography angiography demonstrated a 53.2 mm popliteal artery aneurysm causing an ab extrinseco compression of the popliteal vein and a dislocation of popliteal nerve. A surgical open reconstruction with a reinforced Dacron graft was performed via a poster…
Measurement of the Proton-Air Cross Section at root s=57 TeV with the Pierre Auger Observatory
We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)-36+28(syst)]mb is found. © 2012 American Physical Society.
Erratum: The lateral trigger probability function for the ultra-high energy cosmic ray showers detected by the Pierre Auger Observatory (Astroparticle Physics (2011) 35 (266-276))
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Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are du…
Results of a self-triggered prototype system for radio-detection of extensive air showers at the Pierre Auger Observatory
We describe the experimental setup and the results of RAuger, a small radio-antenna array, consisting of three fully autonomous and self-triggered radio-detection stations, installed close to the center of the Surface Detector (SD) of the Pierre Auger Observatory in Argentina. The setup has been designed for the detection of the electric field strength of air showers initiated by ultra-high energy cosmic rays, without using an auxiliary trigger from another detection system. Installed in December 2006, RAuger was terminated in May 2010 after 65 registered coincidences with the SD. The sky map in local angular coordinates (i.e., zenith and azimuth angles) of these events reveals a strong azi…