Constraints on the dynamics, dissipation, and production of VHE neutrinos in relativistic jets are derived using opacity calculations and VHE γ-ray observations. In particular, it is demonstrated how rapid variability of the γ-ray emission at very high energies (> 100 GeV) can be used to map the location of the γ-spheres, to derive lower limits on the Doppler factor of the γ-ray emission zone, ...

We will present a summary of the observations of blazars by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO). EGRET has detected high energy γray emission at energies greater than 100 MeV from more that 50 blazars. These sources show inferred isotropic luminosities as large as 3× 10 ergs s. One of the most remarkable characteristics of the EGRET o...

To understand better the early galactic production of Li, Be, and B by cosmic ray spallation and fusion reactions, the dependence of these production rates on cosmic ray models and model parameters is examined. The sensitivity of elemental and isotopic production to the cosmic ray pathlength magnitude and energy dependence, source spectrum, spallation kinematics, and cross section uncertainties...

A recent discovery concerning the importance of hadron production in space radiation is that pions can contribute up to twenty percent of the dose from galactic cosmic ray interactions (S. Aghara, S. Blattnig, J. Norbury, R. Singleterry, Nuclear Instruments and Methods, Vol. 267, 2009, p. 1115). Although the contribution for dose equivalent will be smaller, the dose contribution could be import...