Narrow Results

The largest amount of antineutrinos detected about the Earth is emitted by the natural radioactive decays of ²³²Th and ²³⁸U chains isotopes and of ⁴⁰K. Other flux components are yielded by cosmic rays interactions in the atmosphere or by possible extra-terrestrial sources such as supernovae explosions, gamma ray bursts, GW events and solar flares. This contribution is aimed to summarise the results obtained by the Borexino experiment about antineutrinos from the Earth and from extraterrestrial sources.

Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) is a nine-collimators satellite detecting X–rays and γ–rays emitted by the Sun during flares. We describe a novel method for the construction of electron flux maps at different electron energies from sets of count visibilities measured by RHESSI. The method requires the application of regularized inversion for the synthesis of electron visibility spectra and of imaging techniques for the reconstruction of two-dimensional electron flux maps. From a physical viewpoint this approach allows the determination of spatially resolved electron spectra whose information content is fundamental for the comprehension of the acceleration mechanisms during the flaring events.

The idea of ‘magnetic reconnection’ has been around since the work of Ronald Giovanelli who proposed it while searching for an explanation of solar flares. The idea seems to have received a boost from the work of James Dungey but he made it very clear in his writing that magnetic lines of force were not physical entities and shouldn’t be treated as such. Bearing this point in mind, attention is concerned here with noting the non-physicality of the whole notion of ‘magnetic reconnection’ and suggesting an alternative approach to seeking explanations for such phenomena as solar flares via the study of plasmas.