Speaker
Mr
Vandad Fallah Ramazani
(Tuorla observatory)
Description
Extreme blazars (EHBLs) are generally characterized by a synchrotron peak located at energies > 1 keV in their SED, and by the hardness of their spectrum in the high-energy (HE, E > 100 MeV) gamma-ray range. So far, only a handful of these objects have been detected in very-high-energy (VHE, E > 100 GeV) gamma rays by imaging atmospheric Cherenkov telescopes (IACTs). Some such objects (e.g. 1ES 0229+200) have shown hard VHE spectra extending to several TeV, making their multi-wavelength emission difficult to interpret naturally with standard, one-zone synchrotron self-Compton models, unlike for non-extreme BL Lac objects. Their GeV-TeV spectra can also shed new light on the blazar sequence. Since 2010, eleven EHBLs have been observed in multi-wavelength campaigns involving the MAGIC IACTs, aiming to increase the number of known EHBL TeV-emitters. Five sources have been clearly detected by MAGIC. This contribution will present the results of these campaigns, including a comparison of the GeV-TeV behavior of these sources with that of the well-known, archetypal EHBL, 1ES 0229+200, as well as interpretations via models that invoke non-conventional mechanisms of electron acceleration.
Are you presenting on behalf of collaborations or institutions?
Yes. MAGIC collaboration
Primary author
Mr
Vandad Fallah Ramazani
(Tuorla observatory)
Co-authors
Antonio Stamerra
(TO)
Dr
Cornelia Arcaro
(North-West University, Potchefstroom, Sout Africa & INAF OAPD, Padova, Italy)
Dr
Elisa Prandini
(Padova University and INFN)
Dr
Giacomo Bonnoli
(Università di Siena & INFN Pisa)
Ms
Josefa Becerra González
(Instituto de Astrofísica de Canarias)
Dr
Katsuaki Asano
(Institute for Cosmic Ray Research, The University of Tokyo)
Luca Foffano
(PD)
