Tracing the ISM magnetic field morphology: the potential of multi-wavelength polarization measurements
Tracing the ISM magnetic field morphology: the potential of multi-wavelength polarization measurements
复制标题
追踪 ISM 磁场形态：多波长偏振测量的潜力
DOI：
10.1051/0004-6361/201323116
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发表时间：
2014
影响因子：
6.5
通讯作者：
D. Seifried
中科院分区：
文献类型：
--
作者：
S. Reissl;S. Wolf;D. Seifried
$\textit{目标}$我们提出了一个案例研究，以证明多波长偏振测量的潜力。目的是研究二向色偏振和热再发射对星际介质（ISM）中磁场跟踪的影响。此外，我们还分析了不完全排列的致密尘埃颗粒对合成的连续偏振图的重要影响。\textit{方法。}$我们开发了一个扩展的三维蒙特-卡罗辐射输运程序MC 3D，在自适应网格上运行，模拟了辐射、磁场和尘埃颗粒之间的相互作用。我们的结果是通过后处理理想的密度分布和复杂的磁流体力学（MHD）崩溃模拟与辐射传输模拟。我们推导出了从7 μ m到1 mm波长范围内不同倾角和尺度下的强度、光学深度、线偏振和圆偏振的空间分辨图。\textit{结果。}$我们预测独特的模式，在不同类型的密度分布和磁场形态的测试设置和复杂的MHD崩溃模拟的线和圆极化图。我们表明，星际尘埃颗粒的排列过程可以显着影响合成偏振图。多波长偏振测量允许人们预测ISM内的磁场形态。复杂结构的偏振测量的解释仍然是模糊的，因为在ISM中的主要参数的大量变化。
$\textit{Aims.}$ We present a case study to demonstrate the potential of multi-wavelength polarization measurements. The aim is to investigate the effects that dichroic polarization and thermal re-emission have on tracing the magnetic field in the interstellar medium (ISM). Furthermore, we analyze the crucial influence of imperfectly aligned compact dust grains on the resulting synthetic continuum polarization maps.$\\ \textit{Methods.}$ We developed an extended version of the well-known 3D Monte-Carlo radiation transport code MC3D for multi-wavelength polarization simulations running on an adaptive grid.We investigated the interplay between radiation, magnetic fields and dust grains. Our results were produced by post-processing both ideal density distributions and sophisticated magnetohydrodynamic (MHD) collapse simulations with radiative transfer simulations. We derived spatially resolved maps of intensity, optical depth, and linear and circular polarization at various inclination angles and scales in a wavelength range from 7 $\mu m$ to 1 $mm$.$\\ \textit{Results.}$ We predict unique patterns in linear and circular polarization maps for different types of density distributions and magnetic field morphologies for test setups and sophisticated MHD collapse simulations. We show that alignment processes of interstellar dust grains can significantly influence the resulting synthetic polarization maps. Multi-wavelength polarization measurements allow one to predict the morphology of the magnetic field inside the ISM. The interpretation of polarization measurements of complex structures still remains ambiguous because of the large variety of the predominant parameters in the ISM.