Title: Positive Latitude e-e+ Annihilation


Proposal ID: 0120147
Subject category: Nucleosynthesis
Principal investigator: von Ballmoos
Institute: Centre d'Etude Spatiale des Rayonnements


Abstract

We propose to verify the existence of the Positive Latitude Annihilation feature, and, if it is confirmed, determine its intensity, the angular and spectral shape, and measure the positronium continuum relative to the line. The proposed grid of pointings is complementary to the raster of the core program GSDE and will result in a uniform exposure over the entire "fountain region". The combination of SPI and IBIS data will allow to lead a comprehensive study on the origin and annihilation site of the positrons in the feature. The present proposal will make it possible to discriminate between the various models for the Positive Latitude Annihilation feature.