ApPolLO：偏振LOFAR源的Apertif对应体
ApPolLO: Apertif counterparts of Polarised LOFAR sources
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中文总结 AI 辅助
利用LOFAR 144 MHz和Apertif 1.4 GHz偏振数据，编制598个偏振源星表，区分源局域与视线方向去偏振，首次给出宇宙纤维RM色散红移相关上限。
中文摘要 AI 辅助
宇宙磁场结构和演化的知识对于理解原初磁场在宇宙寿命期间如何产生和放大至关重要。在显著红移范围内的偏振研究是理解宇宙磁场的重要工具。我们旨在利用（背景）射电源的偏振谱和去偏振特性来理解宇宙磁场的结构和演化。利用来自LOFAR旋转测量（RM）网格星表在144 MHz处的两个不同频率的射电偏振数据，以及Apertif在1.4 GHz处的新数据，我们研究了共同偏振源样本的源统计，推导出这两个频率之间的去偏振比。我们利用这一点来区分源局部的去偏振效应与沿视线方向的去偏振效应。我们编制了一个包含598个偏振射电成分的星表，其中大部分位于低密度环境中。两个波长的分数偏振都随红移而降低。我们将1.4 GHz处的主要去偏振归因于源附近发生的效应，而在144 MHz处测量的去偏振最可能是由沿视线方向的宇宙纤维产生的。我们首次获得了宇宙网纤维中RM色散的红移相关上限估计。
英文摘要
Knowledge of the structure and evolution of cosmic magnetic fields is indispensable to understand how primordial magnetic fields were generated and amplified during the lifetime of the Universe. Polarisation studies over significant redshift ranges are an important tool in understanding cosmic magnetic fields. We aim to understand the structure and evolution of cosmic magnetic fields, utilising the polarised spectra and depolarisation characteristics of (background) radio sources. Using radio polarisation data at two different frequencies from the LOFAR Rotation Measure (RM) grid catalogue at 144\,MHz and new Apertif data at 1.4\,GHz, we investigate the source statistics of a common sample of polarised sources, deriving the depolarisation ratio between these two frequencies. We utilise this to disentangle depolarising effects local to the source from those along the line of sight. We compile a catalogue of 598 polarised radio components, most of which are located in low-density environments. Fractional polarisation decrease for both wavelengths with redshift. We attributed the main depolarisation at 1.4\,GHz to effects occurring close to the sources, while the depolarisation measured at 144\,MHz is most likely generated by cosmic filaments along the line-of-sight. We were able to get a first redshift dependent upper limit estimate of the RM dispersion in cosmic web filaments.
发表机构
- Universität Bielefeld（比勒费尔德大学）
- Ruhr University Bochum（波鸿鲁尔大学）
- Universidad San Francisco de Quito（基多圣弗朗西斯科大学）
机构由 AI 辅助整理，请以论文原文为准。
