Hadronic model for the non-thermal radiation from the binary system AR Scorpii. (9th February 2018)

• Record Type: Journal Article
• Authors: Bednarek, W
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 476:Number 1(2018:May)
• Page Start: L10
• Page End: L14
• Publication Date: 2018-02-09
• Subjects: radiation mechanisms: non-thermal -- pulsars: general -- white dwarfs -- gamma-rays: stars -- X-rays: binaries; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/sly022
• Languages: English
• ISSNs: 1745-3933

Abstract

Abstract: AR Scorpii is a close binary system containing a rotation powered white dwarf and a low-mass M type companion star. This system shows non-thermal emission extending up to the X-ray energy range. We consider hybrid (lepto-hadronic) and pure hadronic models for the high energy non-thermal processes in this binary system. Relativistic electrons and hadrons are assumed to be accelerated in a strongly magnetised, turbulent region formed in collision of a rotating white dwarf magnetosphere and a magnetosphere/dense atmosphere of the M-dwarf star. We propose that the non-thermal X-ray emission is produced either by the primary electrons or the secondary e ± pairs from decay of charged pions created in collisions of hadrons with the companion star atmosphere. We show that the accompanying γ-ray emission from decay of neutral pions, which are produced by these same protons, is expected to be on the detectability level of the present and/or the future satellite and Cherenkov telescopes. The γ-ray observations of the binary system AR Sco should allow us to constrain the efficiency of hadron and electron acceleration and also the details of the radiation processes.