Tuesday, January 12, 2010

Ultra High Energy Cosmic Rays (UHECR)

UHECR Maps: mysteries and surprises
The rise of nucleon UHECR above GZK astronomy made by protons is puzzled by three main mysteries: an unexpected nearby Virgo UHECR suppression, a rich crowded clustering frozen vertically (north-south) along Cen A, a composition suggesting nuclei and not nucleons. The UHECR map, initially consistent with GZK volumes, to day seem to be not much correlated with expected Super Galactic Plane. Moreover slant depth data of UHECR from AUGER airshower shape do not favor the proton but points to a nuclei, while HIRES, on the contrary favors mostly nucleons. We tried to solve the contradictions assuming UHECR as light nuclei (mostly He) spread by planar galactic fields, randomly at vertical axis. The He fragility and its mass and charge explains the Virgo absence (due to opacity above few Mpc) and the Cen A spread clustering (a quarter of the whole sample). However more events and rare doublets and clustering elsewhere are waiting for an answer. Here we foresee hint of new UHECR component: galactic ones. Moreover a careful updated views of UHECR sky over different (Radio,IR,Optics, X,gamma, TeV) background are also favoring forgotten revolutionary Z-shower model. Both Z-Shower, proton GZK and Lightest nuclei UHECR models have dramatic influence on expected UHE neutrino Astronomy: to be soon revealed by UHE tau neutrino induced air-showers in different ways.

Observation of Ultra-high Energy Cosmic Rays
The measurement of ultra-high energy cosmic rays is an unique way to study article interactions at energies which are well above the capability of current accelerators. Significant progress in this field has occurred during last years, particularly due to the measurements made at the Pierre Auger Observatory. The important results which were achieved during last years are described here. Also future plans for the study of cosmic rays are presented.

High Energy Radiation from Black Holes: A Summary
Bright gamma-ray flares observed from sources far beyond our Galaxy are best explained if enormous amounts of energy are liberated by black holes. The highest-energy particles in nature--the ultra-high energy cosmic rays--cannot be confined by the Milky Way's magnetic field, and must originate from sources outside our Galaxy. Here we summarize the themes of our book, "High Energy Radiation from Black Holes: Gamma Rays, Cosmic Rays, and Neutrinos", just published by Princeton University Press. In this book, we develop a mathematical framework that can be used to help establish the nature of gamma-ray sources, to evaluate evidence for cosmic-ray acceleration in blazars, GRBs and microquasars, to decide whether black holes accelerate the ultra-high energy cosmic rays, and to determine whether the Blandford-Znajek mechanism for energy extraction from rotating black holes can explain the differences between gamma-ray blazars and radio-quiet AGNs.

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