Structured jets in BL Lac objects: efficient PeV neutrino factories?

Abstract

The origin of the high-energy neutrinos (0.1$-$1 PeV range) detected by IceCube remains a mystery. In this work we explore the possibility that efficient neutrino production can occur in structured jets of BL Lac objects, characterized by a fast inner spine surrounded by a slower layer. This scenario has been widely discussed in the framework of the high-energy emission models for BL Lacs and radiogalaxies. One of the relevant consequences of a velocity structure is the enhancement of the inverse Compton emission caused by the radiative coupling of the two zones. We show that a similar boosting could occur for the neutrino output of the spine through the photo-meson reaction of high-energy protons scattering off the amplified soft target photon field of the layer. Assuming the local density and the cosmological evolution of $\gamma$-ray BL Lac derived from {\it Fermi}-LAT data, we calculate the expected diffuse neutrino intensity, that can match the IceCube data for a reasonable choice of the parameters.

5 pages, 2 figures, accepted for publication in ApJ Letters

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Cited by in corpus (6)

• Photohadronic origin of $\gamma$-ray BL Lac emission: implications for IceCube neutrinos
• Spectral analysis of the high-energy IceCube neutrinos
• Through The Ring Of Fire: $\gamma$-Ray Variability In Blazars By A Moving Plasmoid Passing A Local Source Of Seed Photons
• First-Epoch VLBA Imaging of Twenty New TeV Blazars
• Photopion Production in Black-Hole Jets and Flat-Spectrum Radio Quasars as PeV Neutrino Sources
• The blazar paradigm and its discontents