ComPol - A Compton polarimeter in a Nanosat

by Matthias Meier (TUM/MPP)

Thursday 8 Feb 2024, 09:30 → 11:00 Europe/Berlin

E18 Seminar Room

It is hardly possible to resolve the geometry of astrophysical compact objects due to their small size. One possibility to indirectly learn about their structure are polarization measurements. Especially in die hard X-ray range polarization data is still partially missing. Therefore, the aim of the CubeSat mission ComPol is to improve the physical model of the black hole binary system Cygnus X-1 by measuring the polarization of its hard X-ray spectrum.
The detector system developed for the ComPol project is composed of a Silicon drift detector used as a scatterer and a CeBr3 scintillator read out by a SiPM matrix to absorb the scattered X-rays. This way it is possible to capture the full Compton kinematics for each event. The resulting distribution of the azimutal scatter angles allows to directly infer the polarization of the initial radiation.
The talk will give an overview of the scientific motivation, the underlying physics and the detector setup.