Balloon-borne gamma-ray polarimetry

TL;DR

This paper introduces PoGOLite, a balloon-borne instrument designed to measure gamma-ray polarization in the 25-80 keV range, aiming to study high-energy astrophysical sources.

Contribution

It presents the design and planned deployment of a novel balloon-borne gamma-ray polarimeter utilizing Compton scattering for polarization measurement.

Findings

Design of a polarimeter with plastic and BGO scintillators

Scheduled maiden flight in summer 2011 from Esrange

Targeting Crab and Cygnus X-1 for polarization observations

Abstract

The physical processes postulated to explain the high-energy emission mechanisms of compact astrophysical sources often yield polarised soft gamma rays (X-rays). PoGOLite is a balloon-borne polarimeter operating in the 25-80 keV energy band. The polarisation of incident photons is reconstructed using Compton scattering and photoelectric absorption in an array of phoswich detector cells comprising plastic and BGO scintillators, surrounded by a BGO side anticoincidence shield. The polarimeter is aligned to observation targets using a custom attitude control system. The maiden balloon flight is scheduled for summer 2011 from the Esrange Space Centre with the Crab and Cygnus X-1 as the primary observational targets.