Jan 22 – 25, 2019
Europe/Rome timezone



Extreme blazars are an emerging class of jetted active galaxies that is attracting an increasing attention thanks to their extremely energetic emission, signature of exceptional physical conditions in the jet. These objects are characterized by spectral energy distributions with synchrotron emission peaking in the X-ray band above 1017 Hz and gamma-ray emission in the GeV to TeV range.
Multi-frequency observations from radio to very high-energy gamma rays of the brightest known extreme blazars have challenged the standard model of blazar emission. Indeed, these peculiar physical conditions could make the jets of extreme blazars the ideal site for ultra-energetic cosmic rays acceleration and neutrino production. The driving mechanisms for the particle acceleration, as well as the role of hadrons in the observed emission, are still largely unknown.

Recent works have shown how extreme blazars can be used as cosmological probes, e.g., of the extragalactic background light through pair production initiated by TeV gamma rays, or of Lorentz invariance violation possibly inducing a modification of the pair production threshold beyond 10 TeV.

The conference eXtreme19 aims at gathering together scientists from different fields, mainly astronomy, cosmology, astro-particle, and fundamental physics. The main purpose is to review the present experimental and theoretical knowledge of particle acceleration and multi-messenger emission from these extreme accelerators, discussing their potential roles in modern cosmology and fundamental physics.

The meeting will cover the following topics:
  • Extreme blazars and the blazar family
  • Mechanisms of particle acceleration and radiation in jets
  • Extreme blazars as neutrino factories
  • Extreme blazars and the connection with the highest energy cosmic rays
  • Cosmology and fundamental physics
  • Future observatories


Dates: from 22 January 2019 10:00 to 25 January 2019 13:00
Timezone: Europe/Rome

Via Venezia, 12-14


Room: Polo di Psicologia- room 3I (3rd floor, building 2)

Department of Physics and Astronomy   Institute of Nuclear Physics - Padova Section   National Institute of Astronomy - Padua Section       Planetary of Padua