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Constraints on the intergalactic magnetic field from Fermi-LAT observations of GRB 221009A

Lea Burmeister1,2, Paolo Da Vela3,*, Francesco Longo4,5, Guillem Martí-Devesa4,5,†, Manuel Meyer6,‡, Francesco G. Saturni7,8, Antonio Stamerra7, and Péter Veres9,10

  • *Contact author: paolo.davela@inaf.it
  • †Contact author: guillem.marti-devesa@ts.infn.it
  • ‡Contact author: mey@sdu.dk
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Phys. Rev. D 113, 043041 – Published 20 February, 2026

DOI: https://doi.org/10.1103/g8rr-g7p4

Abstract

A cosmological origin of magnetic fields in large scale structures of the Universe would require a non-negligible magnetic field in cosmic voids, which, however, remains undetected. Gamma-ray emission from gamma-ray bursts (GRBs) offers the opportunity to indirectly probe such an intergalactic magnetic field (IGMF), as γ rays interact with cosmic radiation fields, producing electron-positron pairs, and initiate an electromagnetic cascade. The deflection of the pairs in the IGMF results in a time-delayed signal at GeV energies. Using observations with the Fermi Large Area Telescope of the GRB 221009A, we are able to derive the most stringent constraints to date from the nonobservation of the cascade and rule out magnetic fields B<2.5×10−17  G at 95% confidence level for a coherence length larger than 1 Mpc. Our results are comparable to limits obtained from blazar observations but do not suffer from assumptions on the duty cycle of the γ-ray source or whether inverse-Compton scattering losses dominate over the development of plasma instabilities.

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References (57)

  1. R. M. Kulsrud and E. G. Zweibel, On the origin of cosmic magnetic fields, Rep. Prog. Phys. 71, 046901 (2008).
  2. D. Grasso and H. R. Rubinstein, Magnetic fields in the early Universe, Phys. Rep. 348, 163 (2001).
  3. R. Durrer and A. Neronov, Cosmological magnetic fields: Their generation, evolution and observation, Astron. Astrophys. Rev. 21, 62 (2013).
  4. F. Vazza, C. Gheller, F. Zanetti, M. Tsizh, E. Carretti, S. Mtchedlidze, and M. Brüggen, The evolution of cosmic ray electrons in the cosmic web: Seeding by AGN, star formation and shocks, Astron. Astrophys. 696, A58 (2025).
  5. M. S. Pshirkov, P. G. Tinyakov, and F. R. Urban, New limits on extragalactic magnetic fields from rotation measures, Phys. Rev. Lett. 116, 191302 (2016).
  6. R. Alves Batista and A. Saveliev, The gamma-ray window to intergalactic magnetism, Universe 7, 223 (2021).
  7. A. I. Nikishov, Absorption of high-energy photons in the universe, Sov. Phys.–JETP 14, 393 (1962).
  8. R. J. Gould and G. Schréder, Opacity of the universe to high-energy photons, Phys. Rev. Lett. 16, 252 (1966).
  9. A. Neronov and I. Vovk, Evidence for strong extragalactic magnetic fields from Fermi observations of TeV blazars, Science 328, 73 (2010).
  10. A. M. Taylor, I. Vovk, and A. Neronov, Extragalactic magnetic fields constraints from simultaneous GeV-TeV observations of blazars, Astron. Astrophys. 529, A144 (2011).
  11. C. D. Dermer, M. Cavadini, S. Razzaque, J. D. Finke, J. Chiang, and B. Lott, Time delay of cascade radiation for TeV blazars and the measurement of the intergalactic magnetic field, Astrophys. J. Lett. 733, L21 (2011).
  12. F. Tavecchio, G. Ghisellini, G. Bonnoli, and L. Foschini, Extreme TeV blazars and the intergalactic magnetic field, Mon. Not. R. Astron. Soc. 414, 3566 (2011).
  13. M. Ackermann, M. Ajello, L. Baldini et al., The search for spatial extension in high-latitude sources detected by the Fermi large area telescope, Astrophys. J. Suppl. Ser. 237, 32 (2018).
  14. F. Aharonian, J. Aschersleben, M. Backes et al., Constraints on the intergalactic magnetic field using Fermi-LAT and H. E. S. S. blazar observations, Astrophys. J. Lett. 950, L16 (2023).
  15. V. A. Acciari, I. Agudo, T. Aniello et al., A lower bound on intergalactic magnetic fields from time variability of 1ES 0229+200 from MAGIC and Fermi/LAT observations, Astron. Astrophys. 670, A145 (2023).
  16. V. A. Acciari, S. Ansoldi et al. (MAGIC Collaboration), Teraelectronvolt emission from the γ-ray burst GRB 190114C, Nature (London) 575, 455 (2019).
  17. H. Abdalla, R. Adam, F. Aharonian et al., A very-high-energy component deep in the γ-ray burst afterglow, Nature (London) 575, 464 (2019).
  18. R. Plaga, Detecting intergalactic magnetic fields using time delays in pulses of γ-rays, Nature (London) 374, 430 (1995).
  19. S. Razzaque, P. Mészáros, and B. Zhang, GeV and higher energy photon interactions in gamma-ray burst fireballs and surroundings, Astrophys. J. 613, 1072 (2004).
  20. K. Murase, K. Takahashi, S. Inoue, K. Ichiki, and S. Nagataki, Probing intergalactic magnetic fields in the glast era through pair echo emission from TeV blazars, Astrophys. J. Lett. 686, L67 (2008).
  21. K. Murase, B. Zhang, K. Takahashi, and S. Nagataki, Possible effects of pair echoes on gamma-ray burst afterglow emission, Mon. Not. R. Astron. Soc. 396, 1825 (2009).
  22. K. Takahashi, S. Inoue, K. Ichiki, and T. Nakamura, Probing early cosmic magnetic fields through pair echoes from high-redshift GRBs, Mon. Not. R. Astron. Soc. 410, 2741 (2011).
  23. Z.-R. Wang, S.-Q. Xi, R.-Y. Liu, R. Xue, and X.-Y. Wang, Constraints on the intergalactic magnetic field from γ -ray observations of GRB 190114C, Phys. Rev. D 101, 083004 (2020).
  24. T. A. Dzhatdoev, E. I. Podlesnyi, and I. A. Vaiman, Can we constrain the extragalactic magnetic field from very high energy observations of GRB 190114C?, Phys. Rev. D 102, 123017 (2020).
  25. P. Da Vela, G. Martí-Devesa, F. G. Saturni, P. Veres, A. Stamerra, and F. Longo, Intergalactic magnetic field studies by means of γ -ray emission from GRB 190114C, Phys. Rev. D 107, 063030 (2023).
  26. I. Vovk, Search of the pair echo signatures in the high-energy light curve of GRB190114C, Phys. Rev. D 107, 043020 (2023).
  27. Y.-Y. Huang, C.-Y. Dai, H.-M. Zhang, Ruo-Y. Liu, and X.-Y. Wang, Constraints on the intergalactic magnetic field strength from γ-ray observations of GRB 221009A, Astrophys. J. Lett. 955, L10 (2023).
  28. T. A. Dzhatdoev, E. I. Podlesnyi, and G. I. Rubtsov, First constraints on the strength of the extragalactic magnetic field from γ-ray observations of GRB 221009A, Mon. Not. R. Astron. Soc. 527, L95 (2024).
  29. I. Vovk, A. Korochkin, A. Neronov, and D. Semikoz, Constraint on intergalactic magnetic field from Fermi/LAT observations of the “pair echo” of GRB 221009A, Astron. Astrophys. 683, A25 (2024).
  30. Z. Cao, F. Aharonian et al. (LHAASO Collaboration), A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst, Science 380, 1390 (2023).
  31. Z. Cao, F. Aharonian, Q. An et al., Very high-energy gamma-ray emission beyond 10 TeV from GRB 221009A, Sci. Adv. 9, eadj2778 (2023).
  32. R. Alves Batista, J. Becker Tjus, J. Dörner et al., crpropa 3.2—an advanced framework for high-energy particle propagation in extragalactic and galactic spaces, J. Cosmol. Astropart. Phys. 09 (2022) 035.
  33. P. Veres, E. Burns, E. Bissaldi et al., GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB, GRB Coordinates Network 32636, 1 (2022).
  34. A. de Ugarte Postigo, L. Izzo, G. Pugliese et al., GRB 221009A: Redshift from X-shooter/VLT, GRB Coordinates Network 32648, 1 (2022).
  35. E. Bissaldi, N. Omodei, M. Kerr, and Fermi-LAT Team, GRB 221009A or swift J1913.1+1946: Fermi-LAT detection, GRB Coordinates Network 32637, 1 (2022).
  36. S. Dichiara, J. D. Gropp, J. A. Kennea et al., Swift J1913.1+1946 a new bright hard X-ray and optical transient, GRB Coordinates Network 32632, 1 (2022).
  37. Z. Cao, M.-J. Chen, H.-B. Chen, Song-Zhan Hu et al., Introduction to large high altitude air shower observatory (LHAASO), Chin. Astron. Astrophys. 43, 457 (2019).
  38. X.-H. Ma, Y.-J. Bi, Z. Cao et al., Chapter 1 LHAASO instruments and detector technology, Chin. Phys. C 46, 030001 (2022).
  39. O. Kalashev, A. Korochkin, A. Neronov, and D. Semikoz, Modeling the propagation of very-high-energy γ-rays with the CRbeam code: Comparison with crpropa and ELMAG codes, Astron. Astrophys. 675, A132 (2023).
  40. M. Axelsson, M. Ajello, M. Arimoto et al., GRB 221009A: The B. O. A. T. burst that shines in gamma rays, Astrophys. J. Suppl. Ser. 277, 24 (2025).
  41. A. Neronov and D. V. Semikoz, Sensitivity of γ-ray telescopes for detection of magnetic fields in the intergalactic medium, Phys. Rev. D 80, 123012 (2009).
  42. W. B. Atwood, A. A. Abdo, M. Ackermann et al., The Large Area Telescope on the Fermi gamma-ray space telescope mission, Astrophys. J. 697, 1071 (2009).
  43. A. Franceschini, G. Rodighiero, and M. Vaccari, Extragalactic optical-infrared background radiation, its time evolution and the cosmic photon-photon opacity, Astron. Astrophys. 487, 837 (2008).
  44. Z.-Q. Xia, Y. Wang, Q. Yuan, and Y.-Z. Fan, A delayed 400 GeV photon from GRB 221009A and implication on the intergalactic magnetic field, Nat. Commun. 15, 4280 (2024).
  45. C. Caprini and S. Gabici, Gamma-ray observations of blazars and the intergalactic magnetic field spectrum, Phys. Rev. D 91, 123514 (2015).
  46. A. E. Broderick, P. Chang, and C. Pfrommer, The cosmological impact of luminous TeV blazars. I. Implications of plasma instabilities for the intergalactic magnetic field and extragalactic gamma-ray background, Astrophys. J. 752, 22 (2012).
  47. L. Zhou and Y.-C. Zou, Determining the viewing angle from TeV light curve of GRB 221009A, Mon. Not. R. Astron. Soc. 532, 2189 (2024).
  48. S. Abdollahi, F. Acero, M. Ackermann et al., Fermi Large Area Telescope fourth source catalog, Astrophys. J. Suppl. Ser. 247, 33 (2020).
  49. A. Domínguez, J. R. Primack, D. J. Rosario et al., Extragalactic background light inferred from AEGIS galaxy-SED-type fractions, Mon. Not. R. Astron. Soc. 410, 2556 (2011).
  50. J. D. Finke, S. Razzaque, and C. D. Dermer, Modeling the extragalactic background light from stars and dust, Astrophys. J. 712, 238 (2010).
  51. A. Saldana-Lopez, A. Domínguez, P. G. Pérez-González, J. Finke, M. Ajello, J. R Primack, V. S Paliya, and A. Desai, An observational determination of the evolving extragalactic background light from the multiwavelength HST/CANDELS survey in the Fermi and CTA era, Mon. Not. R. Astron. Soc. 507, 5144 (2021).
  52. M. Meyer, J. D. Scargle, and R. D. Blandford, Characterizing the gamma-ray variability of the brightest flat spectrum radio quasars observed with the Fermi LAT, Astrophys. J. 877, 39 (2019).
  53. J. R. Mattox, D. L. Bertsch, J. Chiang et al., The likelihood analysis of EGRET data, Astrophys. J. 461, 396 (1996).
  54. J. Ballet, P. Bruel, T. H. Burnett et al., Fermi Large Area Telescope fourth source catalog data release 4 (4FGL-DR4), arXiv:2307.12546.
  55. R. Sari and A. A. Esin, On the synchrotron self-compton emission from relativistic shocks and its implications for gamma-ray burst afterglows, Astrophys. J. 548, 787 (2001).
  56. A. Panaitescu and P. Kumar, Analytic light curves of gamma-ray burst afterglows: Homogeneous versus wind external media, Astrophys. J. 543, 66 (2000).
  57. J. Chiang and C. D. Dermer, Synchrotron and synchrotron self-compton emission and the blast-wave model of gamma-ray bursts, Astrophys. J. 512, 699 (1999).

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Phys. Rev. D 113, 043041– Published 20 February, 2026
  • Received 24 April 2025
  • Revised 26 August 2025
  • Accepted 15 January 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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