论文标题
通过宽带观察相干无线电发射来阐明B Star HD 133880的复杂磁层
Unraveling the complex magnetosphere of the B star HD 133880 via wideband observation of coherent radio emission
论文作者
论文摘要
HD 133880是通过电子回旋体Maser发射（ECME）的过程，已知产生相干脉冲无线电发射的六个热磁星之一。在本文中，我们在广泛的频率范围内对ECME进行了观察，覆盖了近300-4000 MHz，其中巨大的Metrewave射程望远镜（GMRT）和Karl G. Jansky非常大的阵列（VLA）。这项研究是第一个此类研究，导致发现了该现象的几个有趣特征以及宿主恒星的特征。我们发现ECME脉冲的可观察特性，例如左右圆两极化脉冲之间的时间滞后，脉冲的振幅及其上截止频率似乎取决于相对于视线的恒星方向。我们建议，所有这些现象都超出了理想的图像，可以归因于磁层围绕磁场轴的高度方位型不对称物质分布，这是恒星的高倾斜轴和磁场轴之间的高倾斜度（旋转轴和磁场轴之间的角度）以及脱皮磁场偏离二色皮层的偏差。
HD 133880 is one of the six hot magnetic stars known to produce coherent pulsed radio emission by the process of electron cyclotron maser emission (ECME). In this paper, we present observations of ECME from this star over a wide frequency range, covering nearly 300 - 4000 MHz with the Giant Metrewave Radio Telescope (GMRT) and the Karl G. Jansky Very Large Array (VLA). This study, which is the first of its kind, has led to the discovery of several interesting characteristics of the phenomenon and also of the host star. We find that the observable properties of ECME pulses, e.g. the time lag between right and left circularly polarized pulses, the amplitudes of the pulses, and their upper cut-off frequencies appear to be dependent on the stellar orientation with respect to the line of sight. We suggest that all these phenomena, which are beyond the ideal picture, can be attributed to a highly azimuthally asymmetric matter distribution in the magnetosphere about the magnetic field axis, which is a consequence of both the high obliquity (the angle between rotation axis and the magnetic field axis) of the star and the deviation of the stellar magnetic field from a dipolar topology.
