Feb 18 – 26, 2021
Europe/Rome timezone

Photohadronic modelling of the 2010 gamma-ray flare from Mrk 421

Feb 22, 2021, 11:35 AM
Room 2 (https://unipd.link/NeuTel-ParallelRoom2)

Room 2


Parallel Flash talk Neutrino Telescopes and Multimessenger Astrophysical Models


Mr Alberto Rosales de Leon (Durham University)


Blazars are a subclass of active galactic nuclei (AGNs) that have a relativistic jet with a small viewing angle towards the observer. Recent results based on hadronic scenarios have motivated an ongoing discussion of how a blazar can produce high energy neutrinos during a flaring state and which scenario can successfully describe the observed gamma-ray behavior. Markarian 421 (Mrk 421) is one of the closest and brightest objects in the extragalactic gamma-ray sky and showed flaring activity over a 14-days period in 2010 March. In this work, we describe the performed analysis of Fermi-LAT data from the source focused on the MeV range (100 MeV–1 GeV), and study the possibility of a contribution coming from the pγ interactions between protons and MeV SSC target photons to fit the very high energy (VHE) gamma-ray emission. The fit results were compared with two leptonic models (one-zone and two-zone) using the Akaike Information Criteria (AIC) test, which evaluates goodness-of-fit alongside the simplicity of the model. In all cases, the photohadronic model was favored as a better fit description in comparison to the one-zone leptonic model, and with respect to the two-zone model in the majority of cases. Our results show the potential of a photohadronic contribution to a lepto-hadronic origin of the gamma-ray flux of blazars. Future gamma-ray observations above tens of TeV and below 100 MeV in energy will be crucial to test and discriminate between models.

Primary authors

Mr Alberto Rosales de Leon (Durham University) Dr Anthony Brown (Durham University) Prof. Paula Chadwick (Durham University, UK)

Presentation materials