2020/09/30 by Xavier Rodrigues, Simone Garrappa, Shan Gao +3 · 70 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Blazar #Earth Systems and Cosmic Evolution #Event (particle physics) #Flux (metallurgy) #Gamma-ray bursts and supernovae #Neutrino #Proton #Proton Synchrotron #Synchrotron #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/abe87b
published in The Astrophysical Journal 912(1), 54 (IOP Publishing) · 14 pages, 5 figures
openalex created_date 2020/09/14 · arxiv created 2020/12/04 · openalex publication_date 2021/05/01 · arxiv updated 2021/05/12 · openalex updated_date 2026/08/05
Abstract In 2019 July, the IceCube experiment detected a high-energy neutrino from the direction of the powerful blazar PKS 1502+106. We perform multiwavelength and multimessenger modeling of this source, using a fully selfconsistent one-zone model that includes the contribution of external radiation fields typical of flat-spectrum radio quasars. We identify three different activity states of the blazar: one quiescent state and two flaring states with hard and soft gamma-ray spectra. We find two hadronic models that can describe the multiwavelength emission during all three states: a leptohadronic model with a contribution from photohadronic processes to X-rays and gamma-rays, and a proton synchrotron model, where the emission from keV to 10 GeV comes from proton synchrotron radiation. Both models predict a substantial neutrino flux that is correlated with the gamma-ray and soft X-ray fluxes. Our results are compatible with the detection of a neutrino during the quiescent state, based on event rate statistics. We conclude that the soft X-ray spectra observed during bright flares strongly suggest a hadronic contribution, which can be interpreted as additional evidence for cosmic-ray acceleration in the source independently of neutrino observations. We find that more arguments can be made in favor of the leptohadronic model vis-a-vis the proton synchrotron scenario, such as a lower energetic demand during the quiescent state. However, the same leptohadronic model would be disfavored for flaring states of PKS 1502+106 if no IceCube events were found from the direction of the source before 2010, which would require an archival search.