Detection of nonthermal emission from the bow shock of a massive runaway star
Detection of nonthermal emission from the bow shock of a massive runaway star
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探测大质量失控恒星弓形激波的非热发射
DOI：
10.1051/0004-6361/201015232
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发表时间：
2010
影响因子：
6.5
通讯作者：
A. Araudo
中科院分区：
文献类型：
--
作者：
P. Benaglia;G. Romero;J. Martí;C. S. Peri;A. Araudo
上下文近年来，在寻找粒子可以被加速到相对论能量的地点时，人们已经对大质量早期型恒星的周围进行了检查。碰撞的大质量双星的风区已经被确定为高能辐射源;然而，对于大质量恒星，还有一种不同的情况，那里也可以产生强烈的冲击：由失控的星星与星际介质相互作用的恒星强风作用堆积起来的弓形物质区。目标。我们研究了一颗超大质量逃逸星星BD+43 <$3654产生的弓形激波区，寻找非热射电辐射作为相对论粒子群的证据。方法.我们利用甚大天线阵（VLA）在1.42和4.86 GHz两个频率上观测了BD+43 3654的辐射场，得到了该射电辐射的谱指数图。结果我们第一次探测到一颗大质量逃逸星星的弓形激波的非热射电辐射。结论.在分析了可能起作用的辐射机制后，我们得出结论，所研究的区域可以产生足够的相对论粒子，其辐射可能被即将到来的伽马射线仪器（如CTA North）检测到。
Context. The environs of massive, early-type stars have been inspected in recent years in the search for sites where particles can be accelerated up to relativistic energies. Wind regions of massive binaries that collide have already been established as sources of highenergy emission; however, there is a different scenario for massive stars where strong shocks can also be produced: the bow-shaped region of matter piled up by the action of the stellar strong wind of a runaway star interacting with the interstellar medium. Aims. We study the bow-shock region produced by a very massive runaway star, BD+43 ◦ 3654, to look for nonthermal radio emission as evidence of a relativistic particle population. Methods. We observed the field of BD+43 ◦ 3654 at two frequencies, 1.42 and 4.86 GHz, with the Very Large Array (VLA), and obtained a spectral index map of the radio emission. Results. We have detected, for the first time, nonthermal radio emission from the bow shock of a massive runaway star. Conclusions. After analyzing the radiative mechanisms that can be at work, we conclude that the region under study could produce enough relativistic particles whose radiation might be detectable by forthcoming gamma-ray instruments, like CTA North.