Particle acceleration and non-thermal emission during the V407 Cygni nova outburst
Particle acceleration and non-thermal emission during the V407 Cygni nova outburst
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DOI：
10.1051/0004-6361/201220289
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发表时间：
2012-09
影响因子：
6.5
通讯作者：
Pierrick Martin;G. Dubus
中科院分区：
文献类型：
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作者：
Pierrick Martin;G. Dubus
在2010年，由于新事件的爆发而导致的二进制V407爆发，这导致了≥100次的MEVγ频率。银河宇宙射线。我们的目的是确定高能辐射的加速颗粒的特性，我们开发了一种用于不同的v407 CYG的模型。 γ射线发射主要是麻血性起源主要是由抗光曲线的逆向散射出现的。 ），对于总非热能�1043 ERG两周后，注射时的10％的Nova动能是6％。很可能不是一类Tev-Emitter。
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 43 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.