Counterparts to Single Neutrinos Matthias Kadler Perspectives on the Extragalactic Frontier, Trieste, May 6, 2016

High-Fluence Blazars as Possible Counterparts to PeV Neutrinos Matthias Kadler F. Krauß, K. Mannheim, R. Ojha Perspectives on the Extragalactic Frontier, Trieste, May 6, 2016

IceCube Collaboration 2013; Aartsen et al. 2014

How to locate astrophysical candidate sources? Reduce the field size Use the most significant events Have a physical model

IceCube Collaboration 2013; Aartsen et al. 2014

IceCube Collaboration 2013; Aartsen et al. 2014

Ansatz: p-g in blazar jets Energy threshold: ~PeV Rel. protons (jet) Neutrino Spectrum (G~10, q varies) 100TeV 10 PeV ~1 PeV For details, see Krauß et al. 2014 Neutrino Spectrum (G~10) 100TeV 10 PeV ~1 PeV For details, see Krauß et al. 2014 UV seed photons: e~30eV

Ansatz: p-g in blazar jets Mannheim & Biermann 1998 Mücke et al. 2000 ≤ Integration  need high-fluence FSRQs!

E~1.0PeV E~1.1PeV

Krauß et al. 2014, A&A 566, L7

Krauß et al. 2014, A&A 566, L7 1.71 1.94 1.25 0.25 0.39 0.19 ?

No individual source bright enough The six TANAMI blazars are capable of explaining the observed IceCube PeV flux via p-g! But: No individual source bright enough Scaling factor?

E~2PeV IceCube Collaboration 2013; Aartsen et al. 2014

Kadler et al. 2016, Nat. Phys , DOI: 10.1038 ?

? 13 Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Empirical Scaling Factor Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Theoretical Scaling Factor 100TeV 10 PeV ~1 PeV Nmax Maximum 100TeV 10 PeV ~1 PeV 0.5 Nmax Flavor Corrected 100TeV 10 PeV ~1 PeV 0.25 Nmax FSRQ Fraction 100TeV 10 PeV ~1 PeV 0.0125 Nmax Predicted Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Most individual blazars have very low neutrino expectation values! Look at the very brightest blazars during major outbursts

PKS B1424-418 Kadler et al. 2016, Nat. Phys , DOI: 10.1038

PKS B1424-418 Kadler et al. 2016, Nat. Phys , DOI: 10.1038

PKS B1424-418 Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Kadler et al. 2016, Nat. Phys , DOI: 10.1038

? ? 1.2 4.5 Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Poisson probability: ~11% Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Self-consistent model: Based on measured keV-GeV blazar fluences Explains all-sky PeV neutrino flux Predicts peaked PeV spectra no problem with TeV overprediction Association of BigBird with a single blazar Small chance probability

Chance Coincidence? ~5% Most dramatic blazar outburst of the (far) southern sky Highest-energy neutrino (seen in the southern sky) Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Fundamental Implications (with the 5% kept in mind) Hadronic blazar emission models High-energy cosmic rays Neutrino velocity Lorentz invariance Equivalence principle Kadler et al. 2016, Nat. Phys , DOI: 10.1038

Kadler et al. 2016, Nat. Phys , DOI: 10.1038

(with the 5% kept in mind) Implications (with the 5% kept in mind) Hadronic blazar emission models High-energy cosmic rays Neutrino velocity Lorentz invariance Equivalence principle Kadler et al. 2016, Nat. Phys , DOI: 10.1038; Wang et al. 2016, arXiv:1602.06805; Wei et al. 2016, arXiv:1603.07568