Constraining the Astrophysical Origin of Intergalactic Magnetic Fields
High-energy photons can produce electron–positron pairs upon interacting with the extragalactic background light. These pairs will in turn be deflected by the intergalactic magnetic field (IGMF), before possibly up-scattering photons of the cosmic microwave background, thereby initiating an electrom...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad22dd |
| _version_ | 1797271127804870656 |
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| author | J. Tjemsland M. Meyer F. Vazza |
| author_facet | J. Tjemsland M. Meyer F. Vazza |
| author_sort | J. Tjemsland |
| collection | DOAJ |
| description | High-energy photons can produce electron–positron pairs upon interacting with the extragalactic background light. These pairs will in turn be deflected by the intergalactic magnetic field (IGMF), before possibly up-scattering photons of the cosmic microwave background, thereby initiating an electromagnetic cascade. The nonobservation 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 obtained with the Fermi Large Area Telescope and the High Energy Stereoscopic System to constrain cosmological MHD simulations of various magnetogenesis scenarios, and find that all models without a strong space-filling primordial component or overoptimistic 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 ≳ 0.67, thus excluding most astrophysical production scenarios. Moreover, we set lower limits of B _0 > 5.1 × 10 ^−15 G ( B _0 > 1.0 × 10 ^−14 G) for a space-filling primordial IGMF for a blazar activity time of Δ t = 10 ^4 yr (Δ t = 10 ^7 yr). |
| first_indexed | 2024-04-25T02:15:14Z |
| format | Article |
| id | doaj.art-aad06198bd5c484caf0888bbd9f28619 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-25T02:15:14Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-aad06198bd5c484caf0888bbd9f286192024-03-07T10:03:21ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01963213510.3847/1538-4357/ad22ddConstraining the Astrophysical Origin of Intergalactic Magnetic FieldsJ. Tjemsland0https://orcid.org/0000-0001-5393-4999M. Meyer1F. Vazza2Department of Physics, Norwegian University of Science and Technology , Høgskoleringen 5, 7491 Trondheim, NorwayCP3-Origins, University of Southern Denmark , Campusvej 55, 5230 Odense M, DenmarkDipartimento di Fisica e Astronomia, Universitá di Bologna , Via Gobetti 93/2, 40129 Bologna, Italy; INAF-Istitituto di Radio Astronomia , Via Gobetti 101, 40129 Bologna, Italy; Hamburger Sternwarte, Universität Hamburg , Gojenbergsweg 112, 41029 Hamburg, GermanyHigh-energy photons can produce electron–positron pairs upon interacting with the extragalactic background light. These pairs will in turn be deflected by the intergalactic magnetic field (IGMF), before possibly up-scattering photons of the cosmic microwave background, thereby initiating an electromagnetic cascade. The nonobservation 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 obtained with the Fermi Large Area Telescope and the High Energy Stereoscopic System to constrain cosmological MHD simulations of various magnetogenesis scenarios, and find that all models without a strong space-filling primordial component or overoptimistic 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 ≳ 0.67, thus excluding most astrophysical production scenarios. Moreover, we set lower limits of B _0 > 5.1 × 10 ^−15 G ( B _0 > 1.0 × 10 ^−14 G) for a space-filling primordial IGMF for a blazar activity time of Δ t = 10 ^4 yr (Δ t = 10 ^7 yr).https://doi.org/10.3847/1538-4357/ad22ddIntergalactic mediumExtragalactic astronomyBlazarsExtragalactic magnetic fieldsPrimordial magnetic fields |
| spellingShingle | J. Tjemsland M. Meyer F. Vazza Constraining the Astrophysical Origin of Intergalactic Magnetic Fields The Astrophysical Journal Intergalactic medium Extragalactic astronomy Blazars Extragalactic magnetic fields Primordial magnetic fields |
| title | Constraining the Astrophysical Origin of Intergalactic Magnetic Fields |
| title_full | Constraining the Astrophysical Origin of Intergalactic Magnetic Fields |
| title_fullStr | Constraining the Astrophysical Origin of Intergalactic Magnetic Fields |
| title_full_unstemmed | Constraining the Astrophysical Origin of Intergalactic Magnetic Fields |
| title_short | Constraining the Astrophysical Origin of Intergalactic Magnetic Fields |
| title_sort | constraining the astrophysical origin of intergalactic magnetic fields |
| topic | Intergalactic medium Extragalactic astronomy Blazars Extragalactic magnetic fields Primordial magnetic fields |
| url | https://doi.org/10.3847/1538-4357/ad22dd |
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