Sensitivity of the Cherenkov Telescope Array to the Detection of Intergalactic Magnetic Fields

Abstract

Very high energy (VHE; energy $E\gtrsim 100$GeV) $\gamma$-rays originating from extragalactic sources undergo pair production with low-energy photons of background radiation fields. These pairs can inverse-Compton-scatter background photons, initiating an electromagnetic cascade. The spatial and temporal structure of this secondary $\gamma$-ray signal is altered as the $e^{+}{e}^{-}$ pairs are deflected in an intergalactic magnetic field (IGMF). We investigate how VHE observations with the future Cherenkov Telescope Array with its high angular resolution and broad energy range, can potentially probe the IGMF. We identify promising sources and simulate $\gamma$-ray spectra over a wide range of values of the IGMF strength and coherence length using the publicly available ELMAG Monte Carlo code. Combining simulated observations in a joint likelihood approach, we find that current limits on the IGMF can be significantly improved. The projected sensitivity depends strongly on the time a source has been $\gamma$-ray active and on the emitted maximum $\gamma$-ray energy.

12 pages, 5 figures. Published in The Astrophysical Journal

References in corpus (20)

• Observations of the Crab Nebula with H.E.S.S
• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• On the Origin of Cosmic Magnetic Fields
• Lower limit on the strength and filling factor of extragalactic magnetic fields
• 2FHL: The Second Catalog of Hard Fermi-LAT Sources
• New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200
• Magnetic Field Seeding by Galactic Winds
• Constraints on the Intergalactic Magnetic Field with Gamma-Ray Observations of Blazars
• Hard TeV spectra of blazars and the constraints to the IR intergalactic background
• Gamma-ray induced cascades and magnetic fields in intergalactic medium
• An emerging population of BL Lacs with extreme properties: towards a class of EBL and cosmic magnetic field probes?
• Spectral analysis of Fermi-LAT blazars above 50 GeV
• Gamma-ray observations of blazars and the intergalactic magnetic field spectrum
• Sensitivity of the Cherenkov Telescope Array to the detection of axion-like particles at high gamma-ray opacities
• Detectability of Pair Echos from Gamma-Ray Bursts and Intergalactic Magnetic Fields
• Intergalactic magnetic field spectra from diffuse gamma rays
• Deep Broadband Observations of the Distant Gamma-ray Blazar PKS 1424+240
• Blazar halos as probe for extragalactic magnetic fields and maximal acceleration energy
• A New Model for Gamma-Ray Cascades in Extragalactic Magnetic Fields
• The BL-Lac gamma-ray blazar PKS 0447-439 as a probable member of a group of galaxies at z=0.343

Cited by in corpus (14)

• Search for Spatial Extension in High-Latitude Sources Detected by the Fermi Large Area Telescope
• Simulations of extragalactic magnetic fields and of their observables
• The Gamma-Ray Window to Intergalactic Magnetism
• Search for Magnetically Broadened Cascade Emission From Blazars with VERITAS
• Constraints on the intergalactic magnetic field using Fermi-LAT and H.E.S.S. blazar observations
• Massive Argon Space Telescope (MAST): a concept of heavy time projection chamber for gamma-ray astronomy in the 100 MeV --- 1 TeV energy range
• Simulations and observational tests of primordial magnetic fields from Cosmic Microwave Background constraints
• Physics of cosmological cascades and observable properties
• Axion driven cosmic magneto-genesis during the QCD crossover
• Fundamental Implications of Intergalactic Magnetic Field Observations
• Constraints on the extragalactic magnetic field strength from blazar spectra based on 145 months of Fermi-LAT observations
• Intergalactic medium rotation measure of primordial magnetic fields
• Probing the IGMF with the next generation Cherenkov telescopes
• Imprints of the post recombination dissipation of helical magnetic field on the Cosmic Microwave Background Radiation