Particle acceleration and non-thermal emission during the V407 Cygni nova outburst - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 2013

Particle acceleration and non-thermal emission during the V407 Cygni nova outburst

Résumé

Context. On March 2010, the symbiotic binary V407 Cyg erupted as a result of a nova explosion. The event gave rise to a two-week long burst of ≥ 100 MeV γ-rays detected by Fermi/LAT, a unique observation testifying to particle acceleration in the system.
Aims: The outburst can be considered a scaled-down supernova, with short dynamical time scale, and thus can constitute a test case for theories of the origin of Galactic cosmic rays. We aim at determining the properties of the accelerated particles and identifying the origin of the high-energy radiation.
Methods: We developed a model for diffusive shock acceleration and non-thermal emission in V407 Cyg, complemented by an evaluation of the thermal emission from the shocked plasma. We considered both leptonic and hadronic contributions to the non-thermal processes, and investigated the effect of many binary and nova parameters.
Results: The γ-ray emission is mostly of leptonic origin and arises predominantly from inverse-Compton scattering of the nova light. Matching the light curve requires gas accumulation in the vicinity of the white dwarf, as a consequence of wind accretion, while the spectrum imposes particle scattering close to the Bohm limit in the upstream equipartition magnetic field. The nova accelerated protons (respectively electrons) with energies up to ≃300 GeV (respectively ≃20 GeV), for a total non-thermal energy ≃10 erg after two weeks, representing ≃10% of the initial nova kinetic energy. The electron-to-proton ratio at injection is 6%.
Conclusions: The V407 Cyg eruption can be understood from the same principles that are invoked for particle acceleration in supernova remnants, although without the need for strong magnetic field amplification. The population of novae in symbiotic systems is a negligible source of Galactic cosmic rays, and most likely not a class of TeV-emitters.
Fichier principal
Vignette du fichier
aa20289-12.pdf (1.46 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

insu-03621061 , version 1 (27-03-2022)

Licence

Paternité

Identifiants

Citer

P. Martin, G. Dubus. Particle acceleration and non-thermal emission during the V407 Cygni nova outburst. Astronomy and Astrophysics - A&A, 2013, 551, ⟨10.1051/0004-6361/201220289⟩. ⟨insu-03621061⟩
58 Consultations
37 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More