TENTATIVE EVIDENCE FOR RELATIVISTIC ELECTRONS GENERATED BY THE JET OF THE YOUNG SUN-LIKE STAR DG Tau
TENTATIVE EVIDENCE FOR RELATIVISTIC ELECTRONS GENERATED BY THE JET OF THE YOUNG SUN-LIKE STAR DG Tau
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DOI：
10.1088/2041-8205/792/1/l18
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发表时间：
2014-09-01
影响因子：
7.9
通讯作者：
Buckle, Jane V.
中科院分区：
文献类型：
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作者：
Ainsworth, Rachael E.;Scaife, Anna M. M.;Buckle, Jane V.
最近在一颗大质量原恒星的喷流中发现了同步辐射，这进一步证明了年轻恒星的某些喷流形成特征与活动星系核的高度相对论性喷流相似。我们展示了用巨型米波射电望远镜在325和610兆赫拍摄的年轻的低质量恒星DG Tau的数据，它是太阳诞生后不久的模拟物。这是第一次在如此低的频率下对低质量年轻恒星物体进行调查。我们在DG Tau喷射附近用同步加速器光谱指数检测到发射，并将这种发射解释为与这种流出相关的突出弓形激波。这一结果为粒子加速到相对论能量提供了初步证据，这是由于这种非常低功率的射流对周围介质的冲击影响。我们计算出均分磁场强度B-min近似为0.11 mG，粒子能量E-min近似为4 × 10(40) erg，这是解释DG Tau弓形激波同步辐射的最低要求。这些结果表明低能宇宙射线可能是由年轻的类太阳恒星产生的。
Synchrotron emission has recently been detected in the jet of a massive protostar, providing further evidence that certain jet formation characteristics for young stars are similar to those found for highly relativistic jets from active galactic nuclei. We present data at 325 and 610 MHz taken with the Giant Metrewave Radio Telescope of the young, low-mass star DG Tau, an analog of the Sun soon after its birth. This is the first investigation of a low-mass young stellar object at such low frequencies. We detect emission with a synchrotron spectral index in the proximity of the DG Tau jet and interpret this emission as a prominent bow shock associated with this outflow. This result provides tentative evidence for the acceleration of particles to relativistic energies due to the shock impact of this otherwise very low-power jet against the ambient medium. We calculate the equipartition magnetic field strength B-min approximate to 0.11 mG and particle energy E-min approximate to 4 x 10(40) erg, which are the minimum requirements to account for the synchrotron emission of the DG Tau bow shock. These results suggest the possibility of low energy cosmic rays being generated by young Sun-like stars.