MeV-GeV Polarimetry with $\gamma \to e^{+}{e}^{-}$: Asserting the Performance of Silicon Strip Detectors-Based Telescopes

Abstract

The polarimetry of gamma rays converting to an $e^{+}{e}^{-}$ pair would open a new window on the high-energy gamma-ray sky by, among other things, providing insight into the radiation mechanism in pulsars (curvature or synchrotron) or deciphering the composition of the gamma-ray emitting jets in blazars (leptonic or lepto-hadronic). The performance of polarimeters based on homogeneous active targets (gas detectors (MeV, HARPO) or emulsions (GeV, GRAINE) has been studied both with simulation and by the analysis of data collected with telescope prototypes on linearly-polarised gamma-ray beams, and found to be excellent. The present (Fermi LAT), AGILE and future project (AMEGO, ASTROGAM) gamma-ray missions, though, are using active targets based on silicon strip detectors (SSD). No demonstration of a non-zero effective polarisation asymmetry with SSDs has been published to date, be it only with simulated data, and sensitivity estimations were obtained from an assumed value of the effective polarisation asymmetry. I present a characterisation of the potential of SSD-based active targets for polarimetry with gamma-ray conversions to pairs and the development of various methods to improve on the sensitivity. This work could pave the way to providing the polarimetry of the brightest gamma-ray sources of the sky from the decade of data collected by the Fermi LAT and by AGILE, and to guiding the design of future missions.

arXiv commentSubmitted to Nucl. Instrum. Meth. A

References in corpus (22)

• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• Fermi Large Area Telescope Fourth Source Catalog
• The AGILE Mission
• The e-ASTROGAM mission (exploring the extreme Universe with gamma rays in the MeV-GeV range)
• Analyzing the Data from X-ray Polarimeters with Stokes Parameters
• X-Ray and Gamma-Ray Polarization in Leptonic and Hadronic Jet Models of Blazars
• On understanding the figures of merit for detection and measurement of x-ray polarization
• Polarimetry of cosmic gamma-ray sources above e+e- pair creation threshold
• The first catalog of Fermi-LAT sources below 100 MeV
• Multiwavelength Polarization of Rotation-Powered Pulsars
• Performance measurement of HARPO: a Time Projection Chamber as a gamma-ray telescope and polarimeter
• Demonstration of polarization sensitivity of emulsion-based pair conversion telescope for cosmic gamma-ray polarimetry
• TPC in gamma-ray astronomy above pair-creation threshold
• $\gamma$-ray polarimetry with conversions to $e^{+}{e}^{-}$ pairs: polarization asymmetry and the way to measure it
• HARPO - A Gaseous TPC for High Angular Resolution Gamma-Ray Astronomy and Polarimetry from the MeV to the TeV
• A Pair Polarimeter for Linearly Polarized High Energy Photons
• High Energy Polarization of Blazars : Detection Prospects
• A 5D, polarised, Bethe-Heitler event generator for $\gamma \to e^{+}{e}^{-}$ conversion
• Gamma Ray polarimetry; a new window for the non-thermal Universe
• Charged particle tracking without magnetic field: optimal measurement of track momentum by a Bayesian analysis of the multiple measurements of deflections due to multiple scattering
• HARPO, a gas TPC active target for high-performance $\gamma$-ray astronomy; demonstration of the polarimetry of MeV $\gamma$-rays converting to $e^{+}{e}^{-}$ pair
• Approaching the parameter estimation quality of maximum likelihood via generalized moments

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