STATISTICAL TECHNIQUES FOR DETECTING THE INTERGALACTIC MAGNETIC FIELD FROM LARGE SAMPLES OF EXTRAGALACTIC FARADAY ROTATION DATA
STATISTICAL TECHNIQUES FOR DETECTING THE INTERGALACTIC MAGNETIC FIELD FROM LARGE SAMPLES OF EXTRAGALACTIC FARADAY ROTATION DATA
复制标题
从河外法拉第旋转数据大样本中检测河间磁场的统计技术
DOI：
10.1088/0004-637x/790/2/123
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
D. Ryu
中科院分区：
文献类型：
--
作者：
T. Akahori;B. Gaensler;D. Ryu
河外射电源的旋转测量（RM）网格已被广泛用于研究宇宙磁力。然而，它们探索星系细丝中的星系间磁场（IGMF）的潜力尚不清楚，因为其他法拉第旋转介质（例如射电源本身、介入星系和我们银河系的星际介质）都是重要的贡献者。我们研究统计技术，以便在未来大规模的无线电偏振调查中区分灯丝的法拉第旋转与其他法拉第旋转来源。我们考虑朝向银河系南极的 30° × 30° 视野，同时改变当前和未来观测中检测到的源数量。我们选择位于高红移且未观察到去偏振和光学吸收系统的源，以减少源和介入星系的 RM 贡献。研究发现，高通滤波器可以令人满意地减少银河系的 RM 贡献，因为该分量对银河系高纬度的角尺度将比 IGMF 预期的角尺度大得多。目前的观察尚未提供足够的源密度来估计细丝的 RM。然而，根据即将进行的调查的拟议方法，我们预测 RM 的显着残留应归因于细丝。如果我们选择视线不包含干扰星系且 RM 误差小于几个 rad m−2 的源，那么 IGMF 的预测结构小至 0.°1 的尺度应该可以用平方公里阵列的数据观测到。
Rotation measure (RM) grids of extragalactic radio sources have been widely used for studying cosmic magnetism. However, their potential for exploring the intergalactic magnetic field (IGMF) in filaments of galaxies is unclear, since other Faraday-rotation media such as the radio source itself, intervening galaxies, and the interstellar medium of our Galaxy are all significant contributors. We study statistical techniques for discriminating the Faraday rotation of filaments from other sources of Faraday rotation in future large-scale surveys of radio polarization. We consider a 30° × 30° field of view toward the south Galactic pole, while varying the number of sources detected in both present and future observations. We select sources located at high redshifts and toward which depolarization and optical absorption systems are not observed so as to reduce the RM contributions from the sources and intervening galaxies. It is found that a high-pass filter can satisfactorily reduce the RM contribution from the Galaxy since the angular scale of this component toward high Galactic latitudes would be much larger than that expected for the IGMF. Present observations do not yet provide a sufficient source density to be able to estimate the RM of filaments. However, from the proposed approach with forthcoming surveys, we predict significant residuals of RM that should be ascribable to filaments. The predicted structure of the IGMF down to scales of 0.°1 should be observable with data from the Square Kilometre Array, if we achieve selections of sources toward which sightlines do not contain intervening galaxies and RM errors are less than a few rad m−2.
通过旋转测量宇宙学模拟中的星系互相关来测量宇宙磁场
DOI：
10.1111/j.1365-2966.2010.17166.x
发表时间：
2010
影响因子：
4.8
作者：
Stasyszyn;Donnert
通讯作者：
Donnert
DOI：
10.1111/j.1365-2966.2011.19623.x
发表时间：
2011-01
影响因子：
4.8
作者：
T. Arshakian;R. Beck
通讯作者：
T. Arshakian;R. Beck