Floating at the edge of space - balloon-borne gamma-ray polarimetry

by Prof. Mark Pearce (KTH Fysik)

Thursday 17 Nov 2011, 10:00 → 11:00 Europe/Stockholm

FA32

Our knowledge regarding compact astrophysical objects such as pulsars and accreting black holes stems primarily from observations of emitted X-/gamma-rays. The high energy emissions from such sources are expected to be polarised. The orientation of the polarisation plane and degree of polarisation is a powerful probe of the physical environment around the source. Despite the wealth of sources accessible to polarisation measurements and the importance of these measurements, there have been very few dedicated missions. PoGOLite is a balloon-borne gamma-ray polarimeter operating in the 25 - ~100 keV energy band. The polarisation of incoming photons is reconstructed using Compton scattering and photo-absorption in an array of phoswich detector cells comprising plastic and BGO scintillators, surrounded by a BGO side anticoincidence shield and a polyethylene neutron shield. The design and performance of the PoGOLite instrument will be described. Results from the maiden ‘pathfinder’ flight of PoGOLite took place from the Esrange Space Centre in July 2011 will also be presented.

Slides 111117_Pogo.pdf