Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi
Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi
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DOI：
10.1126/science.abn0567
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发表时间：
2022-02
期刊：
影响因子：
56.9
通讯作者：
H. Collaboration;F. Aharonian;F. Benkhali;E. Anguner;H. Ashkar;Michael Backes;V. Baghmanyan;
中科院分区：
文献类型：
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作者：
H. Collaboration;F. Aharonian;F. Benkhali;E. Anguner;H. Ashkar;Michael Backes;V. Baghmanyan;
周期性的新星是在白色矮星外层重复的热核爆炸，这是由于来自双星伴星的新鲜物质的吸积。当喷射出的物质撞击到伴星星星的风中时产生的冲击可以加速粒子。我们报告了使用高能立体系统（H.E.S.S.）观察到的来自周期性新星RS蛇夫座的甚高能量（VHE; 100千兆电子伏）伽马射线，直到2021年爆发后的1个月。VHE发射的时间分布与较低能量吉电子伏发射的时间分布相似，表明有共同的起源，峰值通量延迟2天。这些观测结果限制了随时间变化的粒子散射模型，有利于强子发射的轻子替代方案。密集风中的冲击为宇宙射线有效加速到非常高的能量提供了有利的环境。描述周期性新星中的质子加速如果一颗白色矮星从星星上剥离物质，那么足够的氢可以在表面积聚，引发热核爆炸，在不破坏白色矮星的情况下喷射物质。它被观测为新星。一些新星已经被发现发射高能伽马射线，但这种发射的起源还不清楚。H.E.S.S.合作观测了2021年的RS Ophiuchi爆发，这是一颗经常性的新星，确定了它在千兆电子伏和兆电子伏能量下的光谱和时间演化。发射物理模型表明，膨胀的新星冲击波有效地加速了质子，提供了伽马射线和宇宙射线的来源。-KTS对周期性新星RS Ophiuchi的伽马射线观测表明质子加速到兆电子伏能量。
Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star’s wind can accelerate particles. We report very-high-energy (VHE; ≳100 giga–electron volts) gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga–electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies. Description Proton acceleration in a recurrent nova If a white dwarf strips material from a companion star, then enough hydrogen can build up on the surface to trigger a thermonuclear explosion, ejecting material without destroying the white dwarf. This is observed as a nova. Some novae have been seen to emit high-energy gamma rays, but the origin of that emission has been unclear. The H.E.S.S. Collaboration observed the 2021 outburst of RS Ophiuchi, a recurrent nova, determining its spectral and temporal evolution at giga–electron volt and tera–electron volt energies. Modeling of the emission physics shows that the expanding nova shock wave efficiently accelerated protons, providing a source of gamma rays and cosmic rays. —KTS Gamma-ray observations of the recurrent nova RS Ophiuchi demonstrate acceleration of protons to tera–electron volt energies.