Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Coincidence of a high-fluence blazar outburst with a PeV-energy neutrino event

Abstract

The astrophysical sources of the extraterrestrial, very high-energy neutrinos detected by the IceCube collaboration remain to be identified. Gamma-ray (γ-ray) blazars have been predicted to yield a cumulative neutrino signal exceeding the atmospheric background above energies of 100 TeV, assuming that both the neutrinos and the γ-ray photons are produced by accelerated protons in relativistic jets. As the background spectrum falls steeply with increasing energy, the individual events with the clearest signature of being of extraterrestrial origin are those at petaelectronvolt energies. Inside the large positional-uncertainty fields of the first two petaelectronvolt neutrinos detected by IceCube, the integrated emission of the blazar population has a sufficiently high electromagnetic flux to explain the detected IceCube events, but fluences of individual objects are too low to make an unambiguous source association. Here, we report that a major outburst of the blazar PKS B1424–418 occurred in temporal and positional coincidence with a third petaelectronvolt-energy neutrino event (HESE-35) detected by IceCube. On the basis of an analysis of the full sample of γ-ray blazars in the HESE-35 field, we show that the long-term average γ-ray emission of blazars as a class is in agreement with both the measured all-sky flux of petaelectronvolt neutrinos and the spectral slope of the IceCube signal. The outburst of PKS B1424–418 provides an energy output high enough to explain the observed petaelectronvolt event, suggestive of a direct physical association.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: TANAMI γ-ray and radio monitoring of PKS B1424-418.
Figure 2: Dynamic SED of PKS B1424–418.

References

  1. Aartsen, M. G. et al. First observation of PeV-energy neutrinos with IceCube. Phys. Rev. Lett. 111, 021103 (2013).

    Article  ADS  Google Scholar 

  2. IceCube collaboration. Evidence for high-energy extraterrestrial neutrinos at the IceCube detector. Science 342, 1242856 (2013).

  3. Aartsen, M. G. et al. Observation of high-energy astrophysical neutrinos in three years of IceCube data. Phys. Rev. Lett. 113, 101101 (2014).

    Article  ADS  Google Scholar 

  4. Aartsen, M. G. et al. Flavor ratio of astrophysical neutrinos above 35 TeV in IceCube. Phys. Rev. Lett. 114, 171102 (2015).

    Article  ADS  Google Scholar 

  5. Krauß, F. et al. TANAMI blazars in the IceCube PeV neutrino fields. Astron. Astrophys. 566, L7 (2014).

    Article  ADS  Google Scholar 

  6. Mannheim, K., Stanev, T. & Biermann, P. L. Neutrinos from flat-spectrum radio quasars. Astron. Astrophys. 260, L1–L3 (1992).

    ADS  Google Scholar 

  7. Mannheim, K. High-energy neutrinos from extragalactic jets. Astropart. Phys. 3, 295–302 (1995).

    Article  ADS  Google Scholar 

  8. Stecker, F. W. PeV neutrinos observed by IceCube from cores of active galactic nuclei. Phys. Rev. D 88, 047301 (2013).

    Article  ADS  Google Scholar 

  9. Fox, D. B., Kashiyama, K. & Mészarós, P. Sub-PeV neutrinos from TeV unidentified sources in the galaxy. Astrophys. J. 774, 74 (2013).

    Article  ADS  Google Scholar 

  10. Taylor, A. M., Gabici, S. & Aharonian, F. Galactic halo origin of the neutrinos detected by IceCube. Phys. Rev. D 89, 103003 (2014).

    ADS  Google Scholar 

  11. Padovani, P. & Resconi, E. Are both BL Lacs and pulsar wind nebulae the astrophysical counterparts of IceCube neutrino events? Mon. Not. R. Astron. Soc. 443, 474–484 (2014).

    Article  ADS  Google Scholar 

  12. Padovani, P., Resconi, E., Giommi, P., Arsioli, B. & Chang, Y. L. Extreme blazars as counterparts of IceCube astrophysical neutrinos. Mon. Not. R. Astron. Soc. 457, 3582–3592 (2016).

    Article  ADS  Google Scholar 

  13. Murase, K., Inoue, Y. & Dermer, C. D. Diffuse neutrino intensity from the inner jets of active galactic nuclei: impacts of external photon fields and the blazar sequence. Phys. Rev. D 90, 023007 (2014).

    ADS  Google Scholar 

  14. Becker Tjus, J., Eichmann, B., Halzen, F., Kheirandish, A. & Saba, S. M. High-energy neutrinos from radio galaxies. Phys. Rev. D 89, 123005 (2014).

    ADS  Google Scholar 

  15. Waxman, E. The origin of IceCube’s neutrinos: cosmic ray accelerators embedded in star forming calorimeters. Preprint at http://arXiv.org/abs/1511.00815 (2015).

  16. Ojha, R. et al. TANAMI: tracking active galactic nuclei with austral milliarcsecond interferometry. I. First-epoch 8.4 GHz images. Astron. Astrophys. 519, A45 (2010).

    Article  Google Scholar 

  17. Kadler, M., Ojha, R. & for the TANAMI Collaboration TANAMI—multiwavelength and multimessenger observations of active galaxies. Astron. Nachr. 336, 499–504 (2015).

    Article  ADS  Google Scholar 

  18. Hillas, A. M. The origin of ultra-high-energy cosmic rays. Annu. Rev. Astron. Astrophys. 22, 425–444 (1984).

    Article  ADS  Google Scholar 

  19. Mannheim, K. & Biermann, P. L. Photomeson production in active galactic nuclei. Astron. Astrophys. 221, 211–220 (1989).

    ADS  Google Scholar 

  20. Mücke, A., Rachen, J. P., Engel, R., Protheroe, R. J. & Stanev, T. Photomeson production in astrophysical sources. Nucl. Phys. Proc. Suppl. B 80, CD-ROM contents 8/10. Preprint at http://arxiv.org/abs/astro-ph/9905153 (2000).

  21. Krauß, F. et al. TANAMI counterparts to IceCube high-energy neutrino events. 2014 Fermi Symp. Proc. eConf C141020.1. Preprint at http://arXiv.org/abs/1502.02147 (2015).

  22. ANTARES Collaboration and TANAMI Collaboration. ANTARES constrains a blazar origin of two IceCube PeV neutrino events. Astron. Astrophys. 576, L8 (2015).

  23. Ackermann, M. et al. The second catalog of active galactic nuclei detected by the Fermi large area telescope. Astrophys. J. 743, 171 (2011).

    Article  ADS  Google Scholar 

  24. Atwood, W. B. et al. The large area telescope on the Fermi gamma-ray space telescope mission. Astrophys. J. 697, 1071–1102 (2009).

    Article  ADS  Google Scholar 

  25. White, G. L. et al. Redshifts of southern radio sources. VII. Astrophys. J. 327, 561–569 (1988).

    Article  ADS  Google Scholar 

  26. Abdo, A. A. et al. Fermi/large area telescope bright gamma-ray source list. Astrophys. J. 183, 46–66 (2009).

    Article  Google Scholar 

  27. Buson, S. et al. Unusual flaring activity in the blazar PKS 1424–418 during 2008–2011. Astron. Astrophys. 569, A40 (2014).

    Article  Google Scholar 

  28. Ojha, R. Increased gamma-ray activity from the FSRQ PKS 1424–41. Astron. Telegram 4494 (2012).

  29. Ciprini, S. & Cutini, S. Swift detection of increased X-ray activity from gamma-ray flaring blazar PKS 1424–41. Astron. Telegram 4770 (2013).

  30. Hasan, I. et al. Latest OIR Mags of PKS 1424–41. Astron. Telegram 4775 (2013).

  31. Nemenashi, P., Gaylard, M. & Ojha, R. Sharp increase of radio flux in flaring blazar PKS 1424–41. Astron. Telegram 4819 (2013).

  32. Ackermann, M. et al. The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV. Astrophys. J. 799, 86 (2015).

    Article  ADS  Google Scholar 

  33. Ajello, M. et al. The origin of the extragalactic gamma-ray background and implications for dark matter annihilation. Astrophys. J. 800, L27 (2015).

    Article  ADS  Google Scholar 

  34. Murase, K. Active galactic nuclei as high-energy neutrino sources. Preprint at http://arXiv.org/abs/1511.01590 (2015).

  35. Mannheim, K. The proton blazar. Astron. Astrophys. 269, 67–76 (1993).

    ADS  Google Scholar 

  36. Mannheim, K. The UV drag on hadronic hot jets as the origin of X-ray irradiation in AGN. Astron. Astrophys. 297, 321–330 (1995).

    ADS  Google Scholar 

  37. Kadler, M. on behalf of the ANTARES and TANAMI collaborations et al. Constraining the Possible Neutrino Spectra of High-Fluence Blazars with ANTARES. Proc. 34th Int. Cosmic Ray Conf. PoS(ICRC2015)729 (2015).

  38. Adrián-Martínez, S. et al. Constraining the neutrino emission of gravitationally lensed flat-spectrum radio quasars with ANTARES data. J. Cosmol. Astropart. Phys. 11, 017 (2014).

    Article  ADS  Google Scholar 

  39. Stecker, F. W., Scully, S. T., Liberati, S. & Mattingly, D. Searching for traces of Planck-scale physics with high energy neutrinos. Phys. Rev. D 91, 045009 (2015).

    ADS  Google Scholar 

  40. Longo, M. J. Tests of relativity from SN1987A. Phys. Rev. D 36, 3276–3277 (1987).

    ADS  Google Scholar 

  41. Halzen, F. & Hooper, D. High energy neutrinos from the TeV Blazar 1ES 1959 + 650. Astropart. Phys. 23, 537–542 (2005).

    Article  ADS  Google Scholar 

  42. Adrián-Martínez, S. et al. Search for neutrino emission from gamma-ray flaring blazars with the ANTARES telescope. Astropart. Phys. 36, 204–210 (2012).

    Article  ADS  Google Scholar 

  43. Reimer, A., Böttcher, M. & Postnikov, S. Neutrino emission in the hadronic synchrotron mirror model: the “Orphan” TeV Flare from 1ES 1959 + 650. Astrophys. J. 630, 186–190 (2005).

    Article  ADS  Google Scholar 

  44. Schoenen, S., Raedel, L. & On behalf of the IceCube Collaboration Detection of a multi-PeV neutrino-induced muon event from the Northern sky with IceCube. Astron. Telegram 7868 (2015).

Download references

Acknowledgements

The authors thank B. Lott, L. Baldini, P. Bruel, S. Digel, J. Finke, D. Gasparini, N. Omodei, J. S. Perkins and A. Reimer for discussions that have significantly improved this publication. We acknowledge support and partial funding by the Deutsche Forschungsgemeinschaft grant WI 1860-10/1 (TANAMI) and GRK 1147, Deutsches Zentrum für Luft- und Raumfahrt grant 50 OR 1311/50 OR 1303/50 OR 1401, the German Ministry for Education and Research (BMBF) grants 05A11WEA and 05A14WE3, the Helmholtz Alliance for Astroparticle Physics (HAP), the Spanish MINECO project AYA2012-38491-C02-01, the Generalitat Valenciana project PROMETEOII/2014/057, the COST MP0905 action ‘Black Holes in a Violent Universe’ and NASA through Fermi Guest Investigator grants NNH09ZDA001N, NNH10ZDA001N, NNH12ZDA001N and NNH13ZDA001N. This study made use of data collected by the Australian Long Baseline Array (LBA) and the AuScope initiative. The LBA is part of the Australia Telescope National Facility, which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. AuScope Ltd is funded under the National Collaborative Research Infrastructure Strategy (NCRIS), an Australian Commonwealth Government Programme. This paper made use of data from the ALMA calibrator database: https://almascience.eso.org/alma-data/calibrator-catalogue. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This paper also made use of up-to-date SMARTS optical/near-infrared light curves that are available at www.astro.yale.edu/smarts/glast/home.php. The Fermi–LAT Collaboration acknowledges support for LAT development, operation and data analysis from NASA and DOE (United States), CEA/Irfu and IN2P3/CNRS (France), ASI and INFN (Italy), MEXT, KEK, and JAXA (Japan), and the K. A. Wallenberg Foundation, the Swedish Research Council and the National Space Board (Sweden). Science analysis support in the operations phase from INAF (Italy) and CNES (France) is also gratefully acknowledged. We thank J. E. Davis and T. Johnson for the development of the slxfig module and the SED scripts that have been used to prepare the figures in this work.

Author information

Authors and Affiliations

Authors

Contributions

The TANAMI programme is coordinated by R.O. and M.Kadler. F.K. led the multiwavelength data analysis and modelled the SED. K.M. led the theoretical interpretation of the SED data. C.M., R.S., J.T., B.C., A.Ka. (Univ. Würzburg), E.R., R.O. and M.Kadler analysed the LBA data. J.W. and N.G. were responsible for X-ray observations and data analysis. T.B., S.B., C.G., C.M., D.E.G., A.Kreikenbohm, K.L., E.L., F.L., T.S. and J.A.Z. contributed to the analysis and discussion of radio, optical/ultraviolet, X-ray and γ-ray data. LBA observations were conducted by P.G.E., S.G., H.H., S.H., J.E.J.L., T.N., C.Phillips, C.Plötz., J.Q., J.S., A.K.T. and S.W. Hard X-ray data were reduced and analysed by T.B., I.K., W.B. and M.L. G.A., T.E., D.E., C.W.J., A.Ka. (ECAP), U.K. and M.Kreter contributed to the discussion of neutrino astronomy aspects. M.Kadler, F.W.S. and J.S. led the neutrino-velocity discussion. D.J.T., R.O. and M.Kadler coordinated the TANAMI–LAT collaboration liaison. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to M. Kadler.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 836 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kadler, M., Krauß, F., Mannheim, K. et al. Coincidence of a high-fluence blazar outburst with a PeV-energy neutrino event. Nature Phys 12, 807–814 (2016). https://doi.org/10.1038/nphys3715

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphys3715

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing