论文标题
M87核中的线性极化在7 mm和1.3 cm处
Linear polarization in the nucleus of M87 at 7 mm and 1.3 cm
论文作者
论文摘要
我们使用非常长的基线阵列（$λ= $ 1.3 cm）和43 GHz（$λ= $ 7毫米）在2017- 2018年报告了附近射线星系M87的高角度分辨率观测值。提出了核区域的线性极化子结构的新图像，其特征是围绕43 GHz核心围绕极化平面的两组分模式和平滑旋转。从与2007年以来的类似数据集进行比较，我们发现这种全局极化模式在11年的时间间隔内保持稳定，同时显示出较小的月尺度差异。我们讨论了可能以厘米至毫米波长向M87核的法拉第旋转。这些结果可以在观察到的偏振模式与封闭的磁性流动力风中的磁结构相关的情况下进行解释，后者也是观察到的法拉第旋转的来源。
We report on high angular resolution polarimetric observations of the nearby radio galaxy M87 using the Very Long Baseline Array at 24 GHz ($λ=$1.3 cm) and 43 GHz ($λ=$7 mm) in 2017-2018. New images of the linear polarization substructure in the nuclear region are presented, characterized by a two-component pattern of polarized intensity and smooth rotation of the polarization plane around the 43 GHz core. From a comparison with an analogous dataset from 2007, we find that this global polarization pattern remains stable on a time interval of 11 yr, while showing smaller month-scale variability. We discuss the possible Faraday rotation toward the M87 nucleus at centimeter to millimeter wavelengths. These results can be interpreted in a scenario where the observed polarimetric pattern is associated with the magnetic structure in the confining magnetohydrodynamic wind, which also serves as the source of the observed Faraday rotation.
