A multi-messenger investigation of magnetic fields in the Local Universe

在拟议的项目中，我们将研究如何通过各种信使探测几兆秒差距到几千兆秒差距之间的磁场的问题。具体而言，我们将解决以下问题：1。宇宙网的无线电观测如何被用来推断大尺度磁场的性质？2. UHECR观测如何告诉我们局部宇宙中磁场的性质？3.河外磁场对来自高红移源的GeV-TeV光子传输的影响有多大？ 我们如何使用这个信号来限制磁场在> 100 Mpc尺度上的分布？为此目的，我们将产生约束宇宙学模拟，并通过产生（i）模拟观测相对论电子在冲击波加速时发射的射电辐射，（ii）人造宇宙线事件，方法是把取自本地活动星系核目录的超高频ECR源加入我们的模拟中，并使用CRPropa程式模拟超高频ECR的传播模拟高能光子和电子与河外背景光相互作用引发的电磁级联;（四）在宇宙磁场存在下光子转化为类轴子粒子的模型。

In the proposed project we will study the question of how magnetic fields on scales between several Megaparsecs to several Gigaparsecs can be probed by various messengers. In particular, we will address the following questions:1. How can radio observations of the cosmic web be used to infer properties of large-scale magnetic fields?2. How can UHECR observations inform us about the properties of magnetic fields in the local Universe?3. How large is the effect caused by extragalactic magnetic fields onto the propagation of GeV-TeV photons from high-redshift source? How can we use this signal to constrain the distribution of magnetic fields on > 100 Mpc scales?For this purpose we will produce constrained cosmological simulations and analyse them by producing(i) mock observations of the radio emission emitted by relativistic electrons accelerated at shock waves, (ii) artificial cosmic-ray events by populating our simulation with UHECR sources taken from a catalogue of local active galactic nuclei and simulating the propagation of UHECRs using the code CRPropa(iii) simulations of electromagnetic cascades initiated by high-energy photons and electrons interacting with extragalactic background light,and(iv) models of the conversion of photons into axion-like particles in the presence of cosmic magnetic fields.