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arXiv 1104.3749astro-ph.CO
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宇宙磁场的观测与展望

Cosmic Magnetic Fields: Observations and Prospects

Rainer Beck

摘要:

在0.2-10 GHz的射频下的同步辐射、其偏振和法拉第旋转是研究宇宙磁场的强度和结构的有力工具。评述了旋涡星系、棒星系和絮状星系、银河系、星系团晕和遗迹以及星系际介质的观测结果。利用即将到来的大型射电望远镜进行的偏振观测将开启观测宇宙磁场的新纪元,并将有助于了解其起源。在低频率下,LOFAR(10-250 MHz)将使我们能够绘制星系和星系团外部区域和晕圈中弱磁场的结构。正如EVLA、ASKAP、MeerKAT、APERTIF和SKA所观测到的那样,在更高频率(1-10 GHz)下的偏振将以前所未有的细节追踪附近星系盘和中心区域的磁场。对恒星法拉第旋转测量的调查将以高精度绘制银河系的磁场。利用SKA及其前身望远镜ASKAP对偏振背景源密集网格进行法拉第旋转测量的全天巡天,专门用于测量遥远的居间星系、星系团和星系间细丝中的磁场,并将用于模拟银河系中磁场的总体结构和强度。

英文摘要:

Synchrotron emission, its polarization and its Faraday rotation at radio frequencies of 0.2-10 GHz are powerful tools to study the strength and structure of cosmic magnetic fields. The observational results are reviewed for spiral, barred and flocculent galaxies, the Milky Way, halos and relics of galaxy clusters, and for the intergalactic medium. Polarization observations with the forthcoming large radio telescopes will open a new era in the observation of cosmic magnetic fields and will help to understand their origin. At low frequencies, LOFAR (10-250 MHz) will allow us to map the structure of weak magnetic fields in the outer regions and halos of galaxies and galaxy clusters. Polarization at higher frequencies (1-10 GHz), as observed with the EVLA, ASKAP, MeerKAT, APERTIF and the SKA, will trace magnetic fields in the disks and central regions of nearby galaxies in unprecedented detail. Surveys of Faraday rotation measures of pulsars will map the Milky Way's magnetic field with high precision. All-sky surveys of Faraday rotation measures towards a dense grid of polarized background sources with the SKA and its precursor telescope ASKAP are dedicated to measure magnetic fields in distant intervening galaxies, galaxy clusters and intergalactic filaments, and will be used to model the overall structure and strength of the magnetic field in the Milky Way.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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