Concept study of a small Compton polarimeter to fly on a CubeSat

TL;DR

This paper presents a concept for a small Compton polarimeter designed for CubeSats to observe gamma-ray polarization from black-hole binaries, demonstrating feasibility through simulations and outlining future development plans.

Contribution

It introduces a novel small-scale Compton polarimeter concept for CubeSat deployment, including design simulations and feasibility analysis for gamma-ray polarization measurements.

Findings

High signal-to-noise ratio achievable for Cyg X-1 observations

Feasibility of small polarimeter with silicon detectors and scintillators

Estimated data telemetry needs for low earth orbit operation

Abstract

Application of cubesats in astronomical observations has been getting more and more mature in recent years. Here we report a concept study of a small Compton polarimeter to fly on a cubesat for observing polarization of soft gamma-rays from a black-hole X-ray binary, Cygnus X-1. Polarization states provide very useful diagnostics on the emission mechanism and the origin of those gamma rays. In our study, we conducted Monte Carlo simulations to decide the basic design of this small polarimeter. Silicon detectors and cerium bromide scintillators were employed in this study. We estimated its on-axis Compton efficiency at different energies and its data telemetry requirement when flying in a low earth orbit. Our results indicate that it is feasible to achieve high signal-to-noise ratio for observing Cyg X-1 with such a small instrument. Based on this study, we will proceed to have a more realistic design and look for opportunities of a cubesat space mission.