Fast radio burst dispersion measures and rotation measures and the origin of intergalactic magnetic fields
Fast radio burst dispersion measures and rotation measures and the origin of intergalactic magnetic fields
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DOI：
10.1093/mnras/stz2033
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发表时间：
2019-07
影响因子：
4.8
通讯作者：
S. Hackstein;M. Bruggen;F. Vazza;B. Gaensler;V. Heesen
中科院分区：
文献类型：
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作者：
S. Hackstein;M. Bruggen;F. Vazza;B. Gaensler;V. Heesen
我们研究了利用快速射电暴的色散测量和旋转测量测量星系间磁场的可能性。使用贝叶斯方法，我们为这些度量的值生成概率密度函数。我们区分了星系间介质、宿主星系和祖星系的局部环境的贡献。为此，我们使用局部宇宙的受限磁流体动力学模拟来计算从银河系位置出发的视线积分。特别是，我们区分了星系间介质中磁场的主要天体物理起源和原始起源。我们测试了不同可能的宿主星系类型，并探测了宿主星系内快速射电暴祖星位置的不同分布函数。在快速射电暴是由磁星产生的假设下，我们使用分析预测来解释当地环境的贡献。我们发现，在红移z≥0.5的星暴矮星系所承载的星风环境中，来自磁星的快速射电暴不到100次，就足以区分星系间磁场的主要原始起源和天体物理起源。然而，这需要以≈1 rad m−2的精度去除银河系的贡献。我们展示了快速射电暴的一个子集的潜在存在，其旋转测量携带了星系间磁场强度及其起源的信息。
We investigate the possibility of measuring intergalactic magnetic fields using the dispersion measures and rotation measures of fast radio bursts. With Bayesian methods, we produce probability density functions for values of these measures. We distinguish between contributions from the intergalactic medium, the host galaxy, and the local environment of the progenitor. To this end, we use constrained, magnetohydrodynamic simulations of the local Universe to compute lines-of-sight integrals from the position of the Milky Way. In particular, we differentiate between predominantly astrophysical and primordial origins of magnetic fields in the intergalactic medium. We test different possible types of host galaxies and probe different distribution functions of fast radio burst progenitor locations inside the host galaxy. Under the assumption that fast radio bursts are produced by magnetars, we use analytic predictions to account for the contribution of the local environment. We find that less than 100 fast radio bursts from magnetars in stellar-wind environments hosted by starburst dwarf galaxies at redshift z ≳ 0.5 suffice to discriminate between predominantly primordial and astrophysical origins of intergalactic magnetic fields. However, this requires the contribution of the Milky Way to be removed with a precision of ≈1 rad m−2. We show the potential existence of a subset of fast radio bursts whose rotation measures carry information on the strength of the intergalactic magnetic field and its origins.