{
  "id": "2306.07672",
  "version": "v1",
  "published": "2023-06-13T10:30:45.000Z",
  "updated": "2023-06-13T10:30:45.000Z",
  "title": "Constraint on intergalactic magnetic field from Fermi/LAT observations of the \"pair echo\" of GRB 221009A",
  "authors": [
    "Ie. Vovk",
    "A. Korochkin",
    "A. Neronov",
    "D. Semikoz"
  ],
  "comment": "4 pages, 2 figues",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Delayed \"pair echo\" signal from interactions of very-high-energy gamma rays in the intergalactic medium can be used for detection of the inter-galactic magnetic field (IGMF). We use the data of Fermi/LAT telescope coupled with LHAASO observatory measurements to confirm the presence of IGMF along the line of sight to the gamma-ray burst GRB221009A. Comparing the Fermi/LAT measurements with the expected level of the pair echo flux, set by the multi-TeV LHAASO detection, we derive a lower bound $10^{-19}$ G on the IGMF with correlation length $l$ larger than 1 Mpc, improving as $l^{-1/2}$ for shorter correlation lengths. This provides an independent verification of existence of a lower bound on IGMF in the voids of the Large Scale Structure, previously derived from the observations of active galactic nuclei.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-06-13T10:30:45.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "intergalactic magnetic field",
      "grb 221009a",
      "fermi/lat observations",
      "correlation length",
      "lower bound"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}