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Gigaelectronvolt emission from a compact binary merger

Abstract

An energetic γ-ray burst (GRB), GRB 211211A, was observed on 11 December 20211,2. Despite its long duration, typically associated with bursts produced by the collapse of massive stars, the observation of an optical-infrared kilonova points to a compact binary merger origin3. Here we report observations of a significant (more than five sigma) transient-like emission in the high-energy γ-rays of GRB 211211A (more than 0.1 gigaelectronvolts) starting 103 seconds after the burst. After an initial phase with a roughly constant flux (about 5 × 10−10 erg per second per square centimetre) lasting about 2 × 104 seconds, the flux started decreasing and soon went undetected. Our detailed modelling of public and dedicated multi-wavelength observations demonstrates that gigaelectronvolt emission from GRB 211211A is in excess with respect to the flux predicted by the state-of-the-art afterglow model at such late time. We explore the possibility that the gigaelectronvolt excess is inverse Compton emission owing to the interaction of a late-time, low-power jet with an external source of photons, and find that kilonova emission can provide the seed photons. Our results open perspectives for observing binary neutron star mergers.

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Fig. 1: Fermi/LAT detection of GRB 211211A.
Fig. 2: High-energy light curves of GRBs observed by Fermi/LAT.
Fig. 3: Multi-wavelength light curves and spectra of GRB 211211A.
Fig. 4: External inverse Compton model contribution.
Fig. 5: The interaction between the low-power jet and the kilonova.

Data availability

Swift/XRT raw data are public and available from the UK Swift Science Data Centre at the University of Leicester. The light-curve data were taken from https://www.swift.ac.uk/xrt_curves/GRB_ID/flux.qdp, where GRB_ID is the GRB observation ID. The spectra were obtained from https://www.swift.ac.uk/xrt_spectra/addspec.php?targ=GRB_ID where GRB_ID is the GRB observation ID. The details of the automatic spectral analysis can be found at https://www.swift.ac.uk/xrt_spectra/docs.php. Swift/UVOT raw data are available at https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/swift.pl. Fermi/LAT raw data are public and can be downloaded using the software GTBURST available at https://fermi.gsfc.nasa.gov/ssc/data/analysis/scitools/gtburst.html. The Fermi/LAT second GRB catalogue data are available at https://www-glast.stanford.edu/pub_data/953/. The VLA data are available at the public repository https://data.nrao.edu/portal/#/. The observation code is 21B-370. XMM-Newton raw data are available at https://www.cosmos.esa.int/web/xmm-newton/xsa. The TNG data are available from the corresponding author upon reasonable request.

Code availability

HEASOFT, XSPEC and PYXSPEC are freely available online at https://heasarc.gsfc.nasa.gov/docs/software/heasoft/, https://heasarc.gsfc.nasa.gov/xanadu/xspec/ and https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/python/html/index.html. GTBURST is part of the Fermi Science Tools package, freely available at https://fermi.gsfc.nasa.gov/ssc/data/analysis/software/. The details of the GTBURST analysis can be found at https://fermi.gsfc.nasa.gov/ssc/data/analysis/scitools/gtburst.html. The XMM-Newton Science Analysis Software is freely available at https://www.cosmos.esa.int/web/xmm-newton/sas-download. SOSTA is part of the XIMAGE software package, freely available at https://heasarc.gsfc.nasa.gov/xanadu/ximage/ximage.html. The ESO eclipse package is available https://www.eso.org/sci/software/eclipse/. The CASA software is available at https://casa.nrao.edu/casa_obtaining.shtml. A tutorial on how to use CASA can be found at https://casaguides.nrao.edu/index.php?title=VLA_Continuum_Tutorial_3C391-CASA6.2.0. emcee is a Python package, available at https://emcee.readthedocs.io/en/stable/user/install/. AFTERGLOWPY is a Python package, available at https://github.com/geoffryan/afterglowpy. All reduced data and computer code are available from the corresponding author upon reasonable request.

References

  1. D’Ai, A. et al. GRB 211211A: Swift detection of a bright burst. GRB Coord. Netw. Circ. No. 31202 (2021).

  2. Fermi GBM Team GRB 211211A: Fermi GBM final real-time localization. GRB Coord. Netw. Circ. No. 31201 (2021).

  3. Rastinejad, J. C. et al. A kilonova following a long-duration gamma-ray burst at 350 Mpc. Nature https://doi.org/10.1038/s41586-022-05390-w (2022).

  4. Narayan, R., Paczynski, B. & Piran, T. Gamma-ray bursts as the death throes of massive binary stars. Astrophys. J. 395, L83 (1992).

    Article  ADS  CAS  Google Scholar 

  5. Rees, M. J. & Meszaros, P. Unsteady outflow models for cosmological gamma-ray bursts. Astrophys. J. 430, L93 (1994).

    Article  ADS  Google Scholar 

  6. Sari, R., Narayan, R. & Piran, T. Cooling timescales and temporal structure of gamma-ray bursts. Astrophys. J. 473, 204 (1996).

    Article  ADS  Google Scholar 

  7. Paczynski, B. & Rhoads, J. E. Radio transients from gamma-ray bursters. Astrophys. J. 418, L5 (1993).

    Article  ADS  Google Scholar 

  8. Sari, R. & Piran, T. Predictions for the very early afterglow and the optical flash. Astrophys. J. 520, 641–649 (1999).

    Article  ADS  Google Scholar 

  9. Kouveliotou, C. et al. Identification of two classes of gamma-ray bursts. Astrophys. J. 413, L101 (1993).

    Article  ADS  CAS  Google Scholar 

  10. Berger, E. Short-duration gamma-ray bursts. Annu. Rev. Astron. Astrophys. 52, 43–105 (2014).

    Article  ADS  Google Scholar 

  11. Woosley, S. E. & Bloom, J. S. The supernova gamma-ray burst connection. Annu. Rev. Astron. Astrophys. 44, 507–556 (2006).

    Article  ADS  CAS  Google Scholar 

  12. Abbott, B. P. et al. GW170817: observation of gravitational waves from a binary neutron star inspiral. Phys. Rev. Lett. 119, 161101 (2017).

    Article  ADS  CAS  Google Scholar 

  13. Abbott, B. P. et al. Multi-messenger observations of a binary neutron star merger. Astrophys. J. 848, L12 (2017).

    Article  ADS  Google Scholar 

  14. Abbott, B. P. et al. Gravitational waves and gamma-rays from a binary neutron star merger: GW170817 and GRB 170817A. Astrophys. J. 848, L13 (2017).

    Article  ADS  Google Scholar 

  15. Li, L.-X. & Paczyński, B. Transient events from neutron star mergers. Astrophys. J. 507, L59–L62 (1998).

    Article  ADS  Google Scholar 

  16. Metzger, B. D. et al. Electromagnetic counterparts of compact object mergers powered by the radioactive decay of r-process nuclei. Mon. Not. R. Astron. Soc. 406, 2650–2662 (2010).

    Article  ADS  Google Scholar 

  17. Tanvir, N. R. et al. A ‘kilonova’ associated with the short-duration γ-ray burst GRB 130603B. Nature 500, 547–549 (2013).

    Article  ADS  CAS  Google Scholar 

  18. Berger, E., Fong, W. & Chornock, R. An r-process kilonova associated with the short-hard GRB 130603B. Astrophys. J. 774, L23 (2013).

    Article  ADS  Google Scholar 

  19. Troja, E. et al. The afterglow and kilonova of the short GRB 160821B. Mon. Not. R. Astron. Soc. 489, 2104–2116 (2019).

    ADS  CAS  Google Scholar 

  20. Ascenzi, S. et al. A luminosity distribution for kilonovae based on short gamma-ray burst afterglows. Mon. Not. R. Astron. Soc. 486, 672–690 (2019).

    Article  ADS  CAS  Google Scholar 

  21. Jin, Z.-P. et al. A kilonova associated with GRB 070809. Nat. Astron. 4, 77–82 (2020).

    Article  ADS  CAS  Google Scholar 

  22. Rossi, A. et al. A comparison between short GRB afterglows and kilonova AT2017gfo: shedding light on kilonovae properties. Mon. Not. R. Astron. Soc. 493, 3379–3397 (2020).

    Article  ADS  CAS  Google Scholar 

  23. Pian, E. et al. Spectroscopic identification of r-process nucleosynthesis in a double neutron-star merger. Nature 551, 67–70 (2017).

    Article  ADS  CAS  Google Scholar 

  24. Smartt, S. J. et al. A kilonova as the electromagnetic counterpart to a gravitational-wave source. Nature 551, 75–79 (2017).

    Article  ADS  CAS  Google Scholar 

  25. Drout, M. R. et al. Light curves of the neutron star merger GW170817/SSS17a: implications for r-process nucleosynthesis. Science 358, 1570–1574 (2017).

    Article  ADS  CAS  Google Scholar 

  26. Xiao, S. et al. The quasi-periodically oscillating precursor of a long gamma-ray burst from a binary neutron star merger. Preprint at https://arxiv.org/abs/2205.02186 (2022).

  27. Ajello, M. et al. A decade of gamma-ray bursts observed by Fermi-LAT: the second GRB catalog. Astrophys. J. 878, 52 (2019).

    Article  ADS  CAS  Google Scholar 

  28. Ajello, M. et al. Fermi-LAT observations of LIGO/Virgo event GW170817. Astrophys. J. 861, 85 (2018).

    Article  ADS  Google Scholar 

  29. Xingxing, H., Jumpei, T. & Qingwen, T. GeV emission of gamma-ray binary with pulsar scenario. Mon. Not. R. Astron. Soc. 494, 3699–3711 (2020).

    Article  ADS  Google Scholar 

  30. Salafia, O. S. & Giacomazzo, B. Accretion-to-jet energy conversion efficiency in GW170817. Astron. Astrophys. 645, A93 (2021).

    Article  ADS  CAS  Google Scholar 

  31. Evans, P. A. et al. Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs. Mon. Not. R. Astron. Soc. 397, 1177–1201 (2009).

    Article  ADS  CAS  Google Scholar 

  32. Kalberla, P. M. W. et al. The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI. Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections. Astron. Astrophys. 440, 775–782 (2005).

    Article  ADS  CAS  Google Scholar 

  33. Belles, A. & D’Ai, A. GRB 211211A: Swift/UVOT detection. GRB Coord. Netw. Circ. No. 31222 (2021).

  34. Schlafly, E. F. & Finkbeiner, D. P. Measuring reddening with Sloan Digital Sky Survey stellar spectra and recalibrating SFD. Astrophys. J. 737, 103 (2011).

    Article  ADS  Google Scholar 

  35. Jiang, S. Q. et al. GRB 211211A: Nanshan/NEXT optical observations. GRB Coord. Netw. Circ. No. 31213 (2021).

  36. Malesani, D. B. et al. GRB 211211A: NOT optical spectroscopy. GRB Coord. Netw. Circ. No. 31221 (2021).

  37. Ito, N. et al. GRB 211211A: MITSuME Akeno optical observation. GRB Coord. Netw. Circ. No. 31217 (2021).

  38. Kumar, H. et al. GRB 211211A: HCT and GIT optical follow up observations. GRB Coord. Netw. Circ. No. (2021).

  39. Strausbaugh, R. & Cucchiara, A. GRB 211211A: LCO optical observations. GRB Coord. Netw. Circ. No. 31214 (2021).

  40. Gupta, R. et al. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope. GGRB Coord. Netw. Circ. No. 31299 (2021).

  41. Moskvitin, A. et al. GRB 211211A: SAO RAS optical observations. GRB Coord. Netw. Circ. No. 31234 (2021).

  42. de Ugarte Postigo, A. et al. GRB 211211A: afterglow detection from CAFOS/2.2m CAHA. GRB Coord. Netw. Circ. No. 31218 (2021).

  43. de Ugarte Postigo, A. et al. GRB 211211A: further observations from CAFOS/2.2m CAHA. GRB Coord. Netw. Circ. No. 31228 (2021).

  44. Levan, A. J. et al. GRB 211211A—Gemini K-band detection. GRB Coord. Netw. Circ. No. 31235 (2021).

  45. Zheng, W. & Filippenko, A. V. GRB 211211A: KAIT optical afterglow candidate. GRB Coord. Netw. Circ. No. 31203 (2021).

  46. Li, W., Filippenko, A. V., Chornock, R. & Jha, S. The Katzman Automatic Imaging Telescope gamma-ray burst alert system, and observations of GRB 020813. Publ. Astron. Soc. Pac. 115, 844–853 (2003).

    Article  ADS  Google Scholar 

  47. McMullin, J. P., Waters, B., Schiebel, D., Young, W. & Golap, K. CASA architecture and applications. In Astronomical Data Analysis Software and Systems XVI: Astronomical Society of the Pacific Conference Series Vol. 376 (eds Shaw, R. A. et al.) 127 (2007).

  48. Ackermann, M. et al. The first Fermi-LAT catalog of sources above 10 GeV. Astrophys. J. Suppl. Ser. 209, 34 (2013).

    Article  ADS  Google Scholar 

  49. Abdollahi, S. et al. Fermi Large Area Telescope fourth source catalog. Astrophys. J. Suppl. Ser. 247, 33 (2020).

    Article  ADS  CAS  Google Scholar 

  50. Ajello, M. et al. A decade of gamma-ray bursts observed by Fermi-LAT: the second GRB catalog. Astrophys. J. 878, 52 (2019).

    Article  ADS  CAS  Google Scholar 

  51. Abdalla, H. et al. A very-high-energy component deep in the γ-ray burst afterglow. Nature 575, 464–467 (2019).

    Article  ADS  CAS  Google Scholar 

  52. Ajello, M. et al. Fermi Large Area Telescope performance after 10 years of operation. Astrophys. J. Suppl. Ser. 256, 12 (2021).

    Article  ADS  CAS  Google Scholar 

  53. Massaro, F. et al. The gamma-ray blazar quest: new optical spectra, state of art and future perspectives. Astrophys. Space Sci. 361, 337 (2016).

    Article  ADS  Google Scholar 

  54. Sanchez, D. A. & Deil, C. Enrico: a Python package to simplify Fermi-LAT analysis. In International Cosmic Ray Conference: International Cosmic Ray Conference Vol. 33, 2784 (2013).

  55. Fermi-LAT collaboration Incremental Fermi Large Area Telescope fourth source catalog. Astrophys. J. Supp. Ser. 260, 53 (2022).

  56. Ackermann, M. et al. Fermi observations of GRB 090510: a short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies. Astrophys. J. 716, 1178–1190 (2010).

    Article  ADS  CAS  Google Scholar 

  57. MichałowskI, M. J. et al. The second-closest gamma-ray burst: sub-luminous GRB 111005A with no supernova in a super-solar metallicity environment. Astron. Astrophys. 616, A169 (2018).

    Article  Google Scholar 

  58. Kumar, P. & Zhang, B. The physics of gamma-ray bursts & relativistic jets. Phys. Rep. 561, 1–109 (2015).

    Article  ADS  Google Scholar 

  59. Sari, R., Piran, T. & Narayan, R. Spectra and light curves of gamma-ray burst afterglows. Astrophys. J. 497, L17–L20 (1998).

    Article  ADS  Google Scholar 

  60. Panaitescu, A. & Kumar, P. Analytic light curves of gamma-ray burst afterglows: homogeneous versus wind external media. Astrophys. J. 543, 66–76 (2000).

    Article  ADS  Google Scholar 

  61. Salafia, O. S. et al. Multi-wavelength view of the close-by GRB 190829A sheds light on gamma-ray burst physics. Astrophys. J. 931, L19 (2022)

  62. Granot, J. & Piran, T. On the lateral expansion of gamma-ray burst jets. Mon. Not. R. Astron. Soc. 421, 570–587 (2012).

    ADS  Google Scholar 

  63. Hotokezaka, K. et al. Mass ejection from the merger of binary neutron stars. Phys. Rev. D 87, 024001 (2013).

    Article  ADS  Google Scholar 

  64. Radice, D. et al. Binary neutron star mergers: mass ejection, electromagnetic counterparts, and nucleosynthesis. Astrophys. J. 869, 130 (2018).

    Article  ADS  CAS  Google Scholar 

  65. Nedora, V. et al. Spiral-wave wind for the blue kilonova. Astrophys. J. 886, L30 (2019).

    Article  ADS  CAS  Google Scholar 

  66. Just, O., Bauswein, A., Ardevol Pulpillo, R., Goriely, S. & Janka, H. T. Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers. Mon. Not. R. Astron. Soc. 448, 541–567 (2015).

    Article  ADS  CAS  Google Scholar 

  67. Siegel, D. M. & Metzger, B. D. Three-dimensional GRMHD simulations of neutrino-cooled accretion disks from neutron star mergers. Astrophys. J. 858, 52 (2018).

    Article  ADS  Google Scholar 

  68. Lippuner, J. & Roberts, L. F. r-process lanthanide production and heating rates in kilonovae. Astrophys. J. 815, 82 (2015).

    Article  ADS  Google Scholar 

  69. Kasen, D., Badnell, N. R. & Barnes, J. Opacities and spectra of the r-process ejecta from neutron star mergers. Astrophys. J. 774, 25 (2013).

    Article  ADS  CAS  Google Scholar 

  70. Korobkin, O., Rosswog, S., Arcones, A. & Winteler, C. On the astrophysical robustness of the neutron star merger r-process. Mon. Not. R. Astron. Soc. 426, 1940–1949 (2012).

    Article  ADS  CAS  Google Scholar 

  71. Metzger, B. D. Kilonovae. Living Rev. Relativ. 23, 1 (2019).

    Article  ADS  Google Scholar 

  72. Grossman, D., Korobkin, O., Rosswog, S. & Piran, T. The long-term evolution of neutron star merger remnants—II. Radioactively powered transients. Mon. Not. R. Astron. Soc. 439, 757–770 (2014).

    Article  ADS  Google Scholar 

  73. Wollaeger, R. T. et al. Impact of ejecta morphology and composition on the electromagnetic signatures of neutron star mergers. Mon. Not. R. Astron. Soc. 478, 3298–3334 (2018).

    Article  ADS  CAS  Google Scholar 

  74. Ciolfi, R. & Kalinani, J. V. Magnetically driven baryon winds from binary neutron star merger remnants and the blue kilonova of 2017 August. Astrophys. J. 900, L35 (2020).

    Article  ADS  CAS  Google Scholar 

  75. Fernández, R., Foucart, F. & Lippuner, J. The landscape of disc outflows from black hole-neutron star mergers. Mon. Not. R. Astron. Soc. 497, 3221–3233 (2020).

    Article  ADS  Google Scholar 

  76. Foreman-Mackey, D., Hogg, D. W., Lang, D. & Goodman, J. emcee: the MCMC hammer. Publ. Astron. Soc. Pac. 125, 306 (2013).

    Article  ADS  Google Scholar 

  77. Spitkovsky, A. Particle acceleration in relativistic collisionless shocks: Fermi process at last? Astrophys. J. 682, L5 (2008).

    Article  ADS  Google Scholar 

  78. Dermer, C. D. & Schlickeiser, R. Model for the high-energy emission from blazars. Astrophys. J. 416, 458 (1993).

    Article  ADS  Google Scholar 

  79. Beloborodov, A. M. Optical and GeV–TeV flashes from gamma-ray bursts. Astrophys. J. 618, L13–L16 (2005).

    Article  ADS  CAS  Google Scholar 

  80. Fan, Y. Z., Zhang, B. & Wei, D. M. Early photon-shock interaction in a stellar wind: a sub-GeV photon flash and high-energy neutrino emission from long gamma-ray bursts. Astrophys. J. 629, 334–340 (2005).

    Article  ADS  Google Scholar 

  81. Murase, K., Toma, K., Yamazaki, R., Nagataki, S. & Ioka, K. High-energy emission as a test of the prior emission model for gamma-ray burst afterglows. Mon. Not. R. Astron. Soc. 402, L54–L58 (2010).

    Article  ADS  Google Scholar 

  82. Murase, K., Toma, K., Yamazaki, R. & Mészáros, P. On the implications of late internal dissipation for shallow-decay afterglow emission and associated high-energy gamma-ray signals. Astrophys. J. 732, 77 (2011).

    Article  ADS  Google Scholar 

  83. Wang, X.-Y., Li, Z. & Mészáros, P. GeV–TeV and X-ray flares from gamma-ray bursts. Astrophys. J. 641, L89–L92 (2006).

    Article  ADS  CAS  Google Scholar 

  84. Fan, Y.-Z., Piran, T., Narayan, R. & Wei, D.-M. High-energy afterglow emission from gamma-ray bursts. Mon. Not. R. Astron. Soc. 384, 1483–1501 (2008).

    Article  ADS  CAS  Google Scholar 

  85. Zhang, B. T., Murase, K., Yuan, C., Kimura, S. S. & Mészáros, P. External inverse-Compton emission associated with extended and plateau emission of short gamma-ray bursts: application to GRB 160821B. Astrophys. J. 908, L36 (2021).

    Article  ADS  Google Scholar 

  86. Murase, K. et al. Double neutron star mergers and short gamma-ray bursts: long-lasting high-energy signatures and remnant dichotomy. Astrophys. J. 854, 60 (2018).

    Article  ADS  Google Scholar 

  87. Fan, Y. & Piran, T. Sub-GeV flashes in γ-ray burst afterglows as probes of underlying bright far-ultraviolet flares. Mon. Not. R. Astron. Soc. 370, L24–L28 (2006).

    Article  ADS  Google Scholar 

  88. Zhang, H., Christie, I. M., Petropoulou, M., Rueda-Becerril, J. M. & Giannios, D. Inverse Compton signatures of gamma-ray burst afterglows. Mon. Not. R. Astron. Soc. 496, 974–986 (2020).

    Article  ADS  CAS  Google Scholar 

  89. Toma, K., Wu, X.-F. & Mészáros, P. An up-scattered cocoon emission model of gamma-ray burst high-energy lags. Astrophys. J. 707, 1404–1416 (2009).

    Article  ADS  Google Scholar 

  90. Kumar, P. & Smoot, G. F. Some implications of inverse-Compton scattering of hot cocoon radiation by relativistic jets in gamma-ray bursts. Mon. Not. R. Astron. Soc. 445, 528–543 (2014).

    Article  ADS  CAS  Google Scholar 

  91. De Colle, F., Lu, W., Kumar, P., Ramirez-Ruiz, E. & Smoot, G. Thermal and non-thermal emission from the cocoon of a gamma-ray burst jet. Mon. Not. R. Astron. Soc. 478, 4553–4564 (2018).

    Article  ADS  Google Scholar 

  92. Kimura, S. S. et al. Upscattered cocoon emission in short gamma-ray bursts as high-energy gamma-ray counterparts to gravitational waves. Astrophys. J. 887, L16 (2019).

    Article  ADS  CAS  Google Scholar 

  93. Zhang, B. The Physics of Gamma-Ray Bursts (Cambridge Univ. Press, Cambridge, 2018).

  94. Burrows, D. N. et al. Bright X-ray flares in gamma-ray burst afterglows. Science 309, 1833–1835 (2005).

    Article  ADS  CAS  Google Scholar 

  95. Falcone, A. D. et al. The giant X-ray flare of GRB 050502B: evidence for late-time internal engine activity. Astrophys. J. 641, 1010–1017 (2006).

    Article  ADS  CAS  Google Scholar 

  96. Chincarini, G. et al. The first survey of X-ray flares from gamma-ray bursts observed by Swift: temporal properties and morphology. Astrophys. J. 671, 1903–1920 (2007).

    Article  ADS  CAS  Google Scholar 

  97. Nousek, J. A. et al. Evidence for a canonical gamma-ray burst afterglow light curve in the Swift XRT data. Astrophys. J. 642, 389–400 (2006).

    Article  ADS  CAS  Google Scholar 

  98. Liang, E.-W., Zhang, B.-B. & Zhang, B. A comprehensive analysis of Swift XRT data. II. Diverse physical origins of the shallow decay segment. Astrophys. J. 670, 565–583 (2007).

    Article  ADS  CAS  Google Scholar 

  99. Zhang, B. et al. Physical processes shaping gamma-ray burst X-ray afterglow light curves: theoretical implications from the Swift X-ray telescope observations. Astrophys. J. 642, 354–370 (2006).

    Article  ADS  CAS  Google Scholar 

  100. Ghisellini, G., Ghirlanda, G., Nava, L. & Firmani, C. "Late prompt” emission in gamma-ray bursts? Astrophys. J. 658, L75–L78 (2007).

    Article  ADS  Google Scholar 

  101. Dai, Z. G. & Lu, T. Gamma-ray burst afterglows and evolution of postburst fireballs with energy injection from strongly magnetic millisecond pulsars. Astron. Astrophys. 333, L87–L90 (1998).

    ADS  Google Scholar 

  102. Zhang, B. & Mészáros, P. Gamma-ray burst afterglow with continuous energy injection: signature of a highly magnetized millisecond pulsar. Astrophys. J. 552, L35–L38 (2001).

    Article  ADS  Google Scholar 

  103. Rosswog, S. Fallback accretion in the aftermath of a compact binary merger. Mon. Not. R. Astron. Soc. 376, L48–L51 (2007).

    Article  ADS  Google Scholar 

  104. Rees, M. J. Tidal disruption of stars by black holes of 106–108 solar masses in nearby galaxies. Nature 333, 523–528 (1988).

    Article  ADS  Google Scholar 

  105. Daigne, F. & Mochkovitch, R. The expected thermal precursors of gamma-ray bursts in the internal shock model. Mon. Not. R. Astron. Soc. 336, 1271–1280 (2002).

    Article  ADS  Google Scholar 

  106. Khangulyan, D., Aharonian, F. A. & Kelner, S. R. Simple analytical approximations for treatment of inverse Compton scattering of relativistic electrons in the blackbody radiation field. Astrophys. J. 783, 100 (2014).

    Article  ADS  Google Scholar 

  107. Yang, J. et al. A long-duration gamma-ray burst with a peculiar origin. Nature https://doi.org/10.1038/s41586-022-05403-8 (2022).

  108. Ryan, G., van Eerten, H., Piro, L. & Troja, E. Gamma-ray burst afterglows in the multimessenger era: numerical models and closure relations. Astrophys. J. 896, 166 (2020).

    Article  ADS  CAS  Google Scholar 

  109. Zhang, H.-M., Huang, Y.-Y., Zheng, J.-H., Liu, R.-Y. & Wang, X.-Y. Fermi-LAT detection of a GeV afterglow from a compact stellar merger. Astrophys. J. 933, L22 (2022).

    Article  ADS  Google Scholar 

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Acknowledgements

We thank A. Celotti, G. Ghisellini, A. Segreto, E. Ambrosi and M. Grazia Bernardini for discussions. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. P.D. and S.C. thank N. Schartel for granting XMM-Newton DDT observations. M.B. acknowledges financial support from the Italian Ministry of University and Research (MUR, PRIN 2020 grant 2020KB33TP). M.B. and G.O. acknowledge financial support from the AHEAD2020 project (grant agreement number 871158). B.B., M.B. and P.D. acknowledge financial support from MUR (PRIN 2017 grant 20179ZF5KS). O.S.S. thanks MUR grant 2017MB8AEZ for financial support. P.D. and S.C. acknowledge support from ASI grant I/004/11/5. This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester.

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A.M., B.B. and G.O. carried out LAT data reduction and analysis, and lead the GeV discovery. O.S.S. performed the multi-wavelength afterglow modelling. G.O. and O.S.S. developed the theoretical model used to interpret the high-energy excess. A.M., B.B., G.O. and O.S.S. lead the paper writing. G.G., M.B., S.G., P.D. and S.R. gave significant inputs on data interpretation. M.B. and G.G. gave major contributions to the paper writing. All authors contributed to discussions and editing of the paper. P.D. is the principal investigator of the XMM-Newton observations, and collected and analysed the optical and UV data. P.D. and S.C. reduced and analysed the XMM data and edited the corresponding text in the paper. S.G. is the principal investigator of the VLA observations. He reduced and analysed the radio data, and edited the corresponding text in the paper. P.T. and A.S. contributed to the LAT analysis providing computational tools. B.B. produced Fig. 1 and Extended Data Fig. 1. A.M. produced Fig. 2 and Extended Data Fig. 2. O.S.S. produced Figs. 3 and 5 and Extended Data Figs. 38. S.R. produced Fig. 5.

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Correspondence to Alessio Mei.

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Extended data figures and tables

Extended Data Fig. 1 Time-averaged broadband spectrum of 4FGL J1410.4+2820.

The two arrows represent the 3σ upper limits for the BL Lac flux obtained using one month of observation by Fermi/LAT before and after the GRB (in yellow and purple, respectively). The green band in the GeV energies represents the time-averaged GeV emission from 12 years of observation55. The emission from the blazar is at least two orders of magnitude weaker than the emission from the GRB.

Extended Data Fig. 2 Comparisons with other GRBs observed by Fermi/LAT.

Long (in green) and short (in blue) bursts emissions from the second Fermi/LAT GRB catalogue27 compared to GRB 211211A (in brown). a, LAT detection time from the burst versus the GRB duration T90 computed with Fermi/GBM data. The dashed lines separate GRBs that are detected during (below) or after (above) the prompt emission. Note that in some cases, including GRB 211211A, the Fermi/LAT observation started after the prompt phase, and we cannot exclude an emission starting before the detection time shown in the plot. b, LAT photon index versus LAT flux (0.1–10 GeV), both obtained through time-integrated analysis in ref. 27.

Extended Data Fig. 3 Corner plot of the 12-dimensional posterior obtained from MCMC sampling.

The meaning of the parameters is explained in the text. The histograms on the diagonal show the one-dimensional marginalized posterior probability density for each parameter, with the red line showing the best fit and the dashed lines bracketing 90% (or 95% in case of upper limits) credible ranges. Contours in the remaining two-dimensional plots show the one-, two- and three-sigma equivalent bounds of the joint posteriors of parameter pairs, while dots show qualitatively the distribution of posterior samples outside the three-sigma boundaries. The red lines and dots show the position of the best fit.

Extended Data Fig. 4 Details on the kilonova photon transverse diffusion.

a, Kilonova luminosity that can diffuse from the jet-kilonova ‘walls’ above the jet dissipation region, located at Rj, at post-merger time t = 104 s. b, Kilonova luminosity available for up-scattering within the jet dissipation region (red solid line), compared to the total kilonova luminosity (blue dashed line), assuming Rj = 1013 cm.

Extended Data Fig. 5 Light curves as SEDs with models, showing the synchrotron emission from the low-power jet.

a, b, Same as Fig. 3, but showing the model-predicted synchrotron emission from the low-power jet with dot-dashed lines in b.

Extended Data Fig. 6 Comparison with the afterglow modelling in ref. 3.

a, b, Light curves (a) and SEDs (b) with the best-fit parameters from ref. 3.

Extended Data Fig. 7 Comparison with the afterglow modelling in ref. 107.

a, b, Light curves (a) and SEDs (b) with the best-fit parameters from ref. 107.

Extended Data Fig. 8 Comparison with the afterglow modelling in ref.26.

a, b, Light curves (a) and SEDs (b) with the best-fit parameters from ref. 26.

Extended Data Table 1 High-energy photons from GRB 211211A detected by Fermi/LAT
Extended Data Table 2 Results of the forward shock + kilonova model fit

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Mei, A., Banerjee, B., Oganesyan, G. et al. Gigaelectronvolt emission from a compact binary merger. Nature 612, 236–239 (2022). https://doi.org/10.1038/s41586-022-05404-7

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