2021ApJ...906...91S

The high-energy-peaked blazar 1ES 1959+650 is a well-known and well-studied nearby blazar that has undergone several episodes of multi-TeV flaring. In 2002 for the first time an orphan TeV flare was observed from this blazar. During a multiwavelength campaign from 2016 April 29 to November 21, MAGIC telescopes observed multi-TeV flarings during the nights of 2016 June 13 and 14 and July 1 when the position of the synchrotron peak was found to be above 10¹⁷ Hz. Also observed was that the second peak of the spectral energy distribution shifted toward higher energy and exhibited extreme HBL-like behavior. The photohadronic model, which is very successful at explaining the multi-TeV flaring from many high energy blazars, including 1ES 1959+650, is applied to study the flaring events of 2016. It is observed that the photohadronic model is unable to explain the observed spectra. Here, we use a two-zone photohadronic model to explain the observed spectra. We clearly demonstrate that the low energy regime (zone-1) of the spectra corresponds to the standard flaring events of the high energy blazar and the high energy regime (zone-2) of the spectra is solely due to the extreme nature of the flaring events. Our two-zone photohadronic model explains the multi-TeV flaring events observed by MAGIC telescopes very well.