Ponente
Descripción
Magnetic fields permeate galaxies and clusters, yet their origin remains unclear. They are thought to arise from the amplification of weak seed fields, whose nature (cosmological or astrophysical) is still debated. If magnetic fields have a primordial origin, we expect even the cosmic voids of the Universe to carry traces of magnetization. One way to test this is through gamma-ray observations of extragalactic sources. Very High Energy (VHE, E > 100 GeV) photons interact with extragalactic background light and produce secondary particles. In the presence of an Intergalactic Magnetic Field (IGMF), secondary particles are deflected, producing a time-delayed emission in the GeV domain, known as “pair-echo” emission. The timing and intensity of this signal encode information on the IGMF strength and properties. While previous studies have focused on sources of persistent gamma-ray emission like active galactic nuclei, the recent detection of VHE photons from Gamma-Ray Bursts (GRBs) opens a new path: their transient nature and cosmological distances make them uniquely powerful probes of cosmic magnetism. In this talk, we present a comprehensive detectability study of pair-echo signatures from GRBs in the tens to hundreds of GeV range. We simulate the afterglow emission for a sample of GRBs with a broad range of properties such as energetics, redshift and jet opening angle and convolve it with the expected pair-echo emission for different IGMF strengths. We explore how intrinsic GRB features influence the resulting pair-echo emission, identifying the most promising scenarios for detection with future gamma-ray facilities.
