Probing Early Cosmic Magnetic Fields through Pair Echos from High-Redshift GRBs

Abstract

We discuss the expected properties of pair echo emission from gamma-ray bursts (GRBs) at high redshifts ($z\gtrsim 5$), their detectability, and the consequent implications for probing intergalactic magnetic fields (IGMFs) at early epochs. Pair echos comprise inverse Compton emission by secondary electron-positron pairs produced via interactions between primary gamma-rays from the GRB and low-energy photons of the diffuse intergalactic radiation, arriving with a time delay that depends on the nature of the intervening IGMFs. At sufficiently high $z$, the IGMFs are unlikely to have been significantly contaminated by astrophysical outflows, and the relevant intergalactic radiation may be dominated by the well-understood cosmic microwave background (CMB). Pair echoes from luminous GRBs at $z\sim 5-10$ may be detectable by future facilities such as the Cherenkov Telescope Array or the Advanced Gamma-ray Imaging System, as long as the GRB primary emission extends to multi-TeV energies, the comoving IGMFs at these redshifts are $B\sim 10^{-16}-10^{-15}\mathrm{Gauss}$, and the non-CMB component of the diffuse intergalactic radiation is relatively low. Observations of pair echos from high-$z$ GRBs can provide a unique, in-situ probe of weak IGMFs during the epochs of early structure formation and cosmic reionization.

22 pages, 7 figures

References in corpus (19)

• Evidence for strong extragalactic magnetic fields from Fermi observations of TeV blazars
• Very-High-Energy Gamma Rays from a Distant Quasar: How Transparent Is the Universe?
• z~7-10 Galaxies in the HUDF and GOODS fields, and their UV Luminosity Functions
• Large-scale magnetic fields in the inflationary universe
• Cosmological Magnetic Field: a fossil of density perturbations in the early universe
• Magnetic Field Seeding by Galactic Winds
• The Biermann Battery in Cosmological MHD Simulations of Population III Star Formation
• The Physics and Early History of the Intergalactic Medium
• Gamma-ray induced cascades and magnetic fields in intergalactic medium
• Probing the Nature of the Weakest Intergalactic Magnetic Fields with the High Energy Emission of Gamma-Ray Bursts
• A method of measurement of extragalactic magnetic fields by TeV gamma ray telescopes
• Helical Magnetic Fields from Sphaleron Decay and Baryogenesis
• Detectability of Pair Echos from Gamma-Ray Bursts and Intergalactic Magnetic Fields
• Blazar halos as probe for extragalactic magnetic fields and maximal acceleration energy
• Primordial magnetic fields from second-order cosmological perturbations: Tight coupling approximation
• Generation of Seed Magnetic Field around First Stars:Effects of Radiation Force
• Property of the spectrum of large-scale magnetic fields from inflation
• Diffuse Extragalactic Background Radiation
• Electromagnetic Properties of the Early Universe

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• The Gamma-Ray Window to Intergalactic Magnetism
• Constraining the PopIII IMF with high-z GRBs
• White Paper and Roadmap for Quantum Gravity Phenomenology in the Multi-Messenger Era
• Accessing the population of high redshift Gamma Ray Bursts
• Prospects for Detecting Gamma-Ray Bursts at Very High Energies with the Cherenkov Telescope Array
• Counts of high-redshift GRBs as probe of primordial non-Gaussianities
• Exploring the Intergalactic Magnetic Field by Means of Faraday Tomography
• PopIII signatures in the spectra of PopII/I GRBs
• Properties of the Intergalactic Magnetic Field Constrained by Gamma-ray Observations of Gamma-Ray Bursts
• Constraints on the intergalactic magnetic field from $\gamma$-ray observations of GRB 190114C
• Prospects for the detection of the prompt very-high-energy emission from $\gamma$-ray bursts with the High Altitude Detection of Astronomical Radiation experiment
• Can we constrain the extragalactic magnetic field from very high energy observations of GRB 190114C?
• Evolution of magnetic fields through cosmological perturbation theory
• Detectability of Planck-Scale-Induced Blurring with Gamma-Ray Bursts
• Intergalactic magnetic field studies by means of $\gamma$-ray emission from GRB 190114C
• Probing the IGMF with the next generation Cherenkov telescopes
• Constraints on the intergalactic magnetic field from Fermi-LAT observations of GRB 221009A
• Science Drivers for AGN Observations with the Cherenkov Telescope Array