Multiwavelength observations in 2019-2020 of a new VHE gamma-ray emitter: the flat spectrum radio quasar QSO B1420+326

Discussion timeslot (ZOOM-Meeting): 13. July 2021 - 18:00
ZOOM-Meeting URL: https://desy.zoom.us/j/98542982538
ZOOM-Meeting ID: 98542982538
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/48-Modelling-AGN039s-spectral-energy-distribution-GAD-GAI-MM/77
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-04/5

Abstract:
'The flat-spectrum radio quasar QSO B1420+326 underwent an enhanced gamma-ray flux state seen by Fermi-LAT at the turn of 2019/2020. Compared to the low state both the position and luminosity of the two spectral energy distribution peaks changed by at least two orders of magnitude. The high state resulted in the discovery of the very-high-energy ( larger 100 GeV) gamma-ray emission from the source by the MAGIC telescopes. The organized multiwavelength campaign allow us to trace the broadband emission of the source through different phases of the flaring activity. The source was observed by 20 instruments in radio, near-infrared, optical, ultra-violet, X-ray and gamma-ray bands.rnWe use dedicated optical spectroscopy results to estimate the accretion disk and the dust torus luminosity. The optical spectroscopy shows a prominent FeII bump with flux evolving together with the continuum emission and a MgII line with varying equivalent width. The gamma-ray flare was accompanied by a rotation of the optical polarization vector and emission of a new superluminal radio knot. We model spectral energy distributions in different flare phases in the framework of combined synchrotron-self-Compton and external Compton scenario in which thernshape of the electron energy distribution is determined from cooling processes.'

Authors: Filippo D'Ammando
Co-Authors: Roberto Angioni | Monica Orienti | for the Fermi-LAT Collaboration | Julian Sitarek | Seiya Nozaki | Elina Lindfors | Giacomo Bonnoli | Vandad Fallah Ramazani | for the MAGIC Collaboration | Svetlana Jorstad
Collaboration: Ferrmi-LATMAGIC

Indico-ID: 80
Proceeding URL: https://pos.sissa.it/395/775