Conveners
Theory: Theory 1
- Markus Boettcher (North-West University)
Theory: Theory 2
- Michael Zacharias (TP IV, Ruhr-Universität Bochum)
Theory: Theory 3
- Frank Rieger (ZAH Univ. & MPIK Heidelberg)
The flat spectrum radio quasar CTA 102 (z=1.032) has exhibited a tremendous phase of its existence. Since early 2016 the gamma-ray flux level has been significantly higher than in previous years. It was topped by a 4-month long giant outburst, where peak fluxes were more than 100 times higher than the quiescence level. Similar trends are observable in optical and X-ray energies. We have...
BL Lacertae objects (BL Lacs) constitute a rare class of active galactic nuclei (AGNs) with the extreme observational features attributed to the Doppler-boosted emission from a relativistic jet, closely aligned to our line-of-sight. The spectral energy distribution (SED) of these sources, extending over 17-19 orders of the frequency from radio to the TeV energy range, is of non-thermal...
I will highlight recent observational results
concerning the timing characteristics of AGN at gamma-ray
energies with a focus on indications for log-normality
and QPOs. The findings will be discussed in the context
of theoretical approaches to understand the physical
origin of variability in AGN.
The broadband spectral energy distribution (SED) of blazars has two well-separated bumps, one of low energy, peaking at soft X-rays and the other of high energy, peaking at hundreds of GeVs. The SED in most of blazars is well understood through the standard one-zone Self-Synchroton Compton (SSC) emission. However, if that is the case, a strong correlation between X-ray and TeV-emission is...
Blazars are a sub-category of radio-loud Active Galactic Nuclei having their jet pointing towards us and are known for their emission covering practically all frequencies of the electromagnetic spectrum. These sources, in some cases, exhibit a correlation between gamma-ray and radio emission, especially during flaring episodes. In this work, we construct a one zone leptonic model in order to...
I will present a suite of synthetic full Stokes single dish light curves generated from the Turbulent Extreme Multi-Zone (TEMZ) model of blazar emission. These synthetic light curves are created via ray-tracing through the TEMZ jet model and include the effects of optical depth, relativistic aberration, Faraday rotation, Faraday conversion, slow-light interpolation, and beam convolution. We...
This talks reviews general theoretical aspects of modeling the broadband
spectral variability of blazars. Both time-dependent leptonic and lepto-
hadronic models will be discussed. Recent applications to the modeling of
coordinated and unccoordinated (orphan flares) multi-wavelength variability
of several prominent Fermi-LAT blazars will be discussed.
Flaring in blazar jets has been found to occur at TeV energies on rapid timescales as short as minutes, implying the emission originates from a very compact region within the jet. Whilst the physical origin powering such flares is yet to be established, recent particle-in-cell (PIC) simulations have indicated that magnetic reconnection can plausibly produce plasmoids small enough to...
Most research in blazar variability focuses on individual flares to explain acceleration
and radiation mechanisms and improve on current models. These short-time events (minutes,
hours or days) might not be representative of the underlying mechanisms causing small-
amplitude variability and/or continuous emission present most of the time. We therefore
investigate long-term (month to years)...
