Evolution and observational signatures of the cosmic ray electron spectrum in SN 1006

• Verfasst von: Winner, Georg [VerfasserIn]
• Verfasst von: Pfrommer, Christoph [VerfasserIn]
• Verfasst von: Girichidis, Philipp [VerfasserIn]
• Verfasst von: Werhahn, Maria [VerfasserIn]
• Verfasst von: Pais, Matteo [VerfasserIn]
• Titel: Evolution and observational signatures of the cosmic ray electron spectrum in SN 1006
• Verf.angabe: Georg Winner, Christoph Pfrommer, Philipp Girichidis, Maria Werhahn and Matteo Pais
• E-Jahr: 2020
• Jahr: 02 October 2020
• Umfang: 18 S.
• Fussnoten: Gesehen am 11.12.2020
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2020
• Band/Heft Quelle: 499(2020), 2, Seite 2785-2802
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/staa2989
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 174265522X

Abstract

Supernova remnants (SNRs) are believed to be the source of Galactic cosmic rays (CRs). SNR shocks accelerate CR protons and electrons which reveal key insights into the non-thermal physics by means of their synchrotron and γ-ray emission. The remnant SN 1006 is an ideal particle acceleration laboratory because it is observed across all electromagnetic wavelengths from radio to γ-rays. We perform 3D magnetohydrodynamics (MHD) simulations where we include CR protons and follow the CR electron spectrum. By matching the observed morphology and non-thermal spectrum of SN 1006 in radio, X-rays, and γ-rays, we gain new insight into CR electron acceleration and magnetic field amplification. (1) We show that a mixed leptonic-hadronic model is responsible for the γ-ray radiation: while leptonic inverse-Compton emission and hadronic pion-decay emission contribute equally at GeV energies observed by Fermi, TeV energies observed by imaging air Cherenkov telescopes are hadronically dominated. (2) We show that quasi-parallel acceleration (i.e. when the shock propagates at a narrow angle to the upstream magnetic field) is preferred for CR electrons and that the electron acceleration efficiency of radio-emitting GeV electrons at quasi-perpendicular shocks is suppressed at least by a factor ten. This precludes extrapolation of current 1D plasma particle-in-cell simulations of shock acceleration to realistic SNR conditions. (3) To match the radial emission profiles and the γ-ray spectrum, we require a volume-filling, turbulently amplified magnetic field and that the Bell-amplified magnetic field is damped in the immediate post-shock region. Our work connects microscale plasma physics simulations to the scale of SNRs.