Constraining the astrophysical origin of intergalactic magnetic fields

Fuente: arXiv
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Main Authors: Tjemsland, J., Meyer, M., Vazza, F.
Format: Preprint
Published: 2023
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author Tjemsland, J.
Meyer, M.
Vazza, F.
author_facet Tjemsland, J.
Meyer, M.
Vazza, F.
contents High-energy photons can produce electron-positron pairs upon interacting with the extragalactic background light (EBL). These pairs will in turn be deflected by the intergalactic magnetic field (IGMF), before possibly up-scattering photons of the cosmic microwave background (CMB), thereby initiating an electromagnetic cascade. The non-observation of an excess of GeV photons and an extended halo around individual blazars due to this electromagnetic cascade can be used to constrain the properties of the IGMF. In this work, we use publicly available data of 1ES 0229+200 by Fermi LAT and H.E.S.S. to constrain cosmological MHD simulations of various magnetogenesis scenarios, and find that all models without a strong space-filling primordial component or over-optimistic dynamo amplifications can be excluded at the 95% confidence level. In fact, we find that the fraction of space filled by a strong IGMF has to be at least $f\gtrsim 0.67$, thus excluding most astrophysical production scenarios. Moreover, we set the lower limits $B_0>5.1\times 10^{-15}$ G ($B_0>1.0\times 10^{-14}$ G) of a space-filling primordial IGMF for a blazar activity time of $Δt = 10^4$ yr ($Δt = 10^7$ yr).
format Preprint
id arxiv_https___arxiv_org_abs_2311_04273
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Constraining the astrophysical origin of intergalactic magnetic fields
Tjemsland, J.
Meyer, M.
Vazza, F.
High Energy Astrophysical Phenomena
Cosmology and Nongalactic Astrophysics
High-energy photons can produce electron-positron pairs upon interacting with the extragalactic background light (EBL). These pairs will in turn be deflected by the intergalactic magnetic field (IGMF), before possibly up-scattering photons of the cosmic microwave background (CMB), thereby initiating an electromagnetic cascade. The non-observation of an excess of GeV photons and an extended halo around individual blazars due to this electromagnetic cascade can be used to constrain the properties of the IGMF. In this work, we use publicly available data of 1ES 0229+200 by Fermi LAT and H.E.S.S. to constrain cosmological MHD simulations of various magnetogenesis scenarios, and find that all models without a strong space-filling primordial component or over-optimistic dynamo amplifications can be excluded at the 95% confidence level. In fact, we find that the fraction of space filled by a strong IGMF has to be at least $f\gtrsim 0.67$, thus excluding most astrophysical production scenarios. Moreover, we set the lower limits $B_0>5.1\times 10^{-15}$ G ($B_0>1.0\times 10^{-14}$ G) of a space-filling primordial IGMF for a blazar activity time of $Δt = 10^4$ yr ($Δt = 10^7$ yr).
title Constraining the astrophysical origin of intergalactic magnetic fields
topic High Energy Astrophysical Phenomena
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2311.04273