Monitoring the non-thermal Universe 2018

Session

Theory

Sep 18, 2018, 4:15 PM

Cochem (Mosel), Germany

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)

15. Interpretation of the coincident observation of a high energy neutrino and a bright flare of blazar TXS0506+056

Shan Gao (DESY)

9/18/18, 4:15 PM

Oral

On September 22nd 2017, the IceCube Neutrino Observatory reported a muon track from a neutrino with a very good positional accuracy. The alert triggered a number of astronomical follow-up campaigns, and the Fermi gamma-ray telescope found as counterpart an object named TXS0506+056 in a very bright, flaring state; this observation may be the first direct evidence for an extragalactic source of...

11. The long-lasting activity in the FSRQ CTA 102

Michael Zacharias (TP IV, Ruhr-Universität Bochum)

9/18/18, 4:35 PM

Oral

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...

36. Time-resolved SEDs of the variable blazar PKS 1510-089

Andrea Gokus

9/18/18, 4:55 PM

Oral

Recent detections of coincidences between high-energy neutrinos and blazars in flaring states or outbursts have revived interest in hadronic emission components of blazar SEDs. However, calorimetric arguments demonstrate that only the very brightest and most-frequent flaring sources have a realistic probability of being detected by current neutrino telescopes. Among the brightest blazar flares...

1. The First and Second-Order Fermi Acceleration Processes in BL Lacertae Objects

Bidzina Kapanadze (Ilia Sate University, Tbilisi, Georgia)

9/18/18, 5:15 PM

Oral

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...

9. Gamma-Ray Astrophysics in the Time Domain

Frank Rieger (ZAH Univ. Heidelberg)

9/19/18, 9:00 AM

Oral

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.

28. Theoretical models to explain the TeV gamma-ray and X-ray correlations exhibited in Blazars.

Nissim Fraija (IA-UNAM)

9/19/18, 9:30 AM

Oral

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...

2. On the connection of radio and γ-ray emission of blazars

Stella Boula (University of Athens)

9/19/18, 9:50 AM

Oral

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...

14. From Electrons to Janskys: Comparing Synthetic TEMZ Model Light Curves to High-Cadence Data from the POLAMI and F-GAMMA Monitoring Programs

Dr Nicholas MacDonald (Max Planck Institute for Radio Astronomy)

9/19/18, 10:10 AM

Oral

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...

3. Models of Blazar Variability

Markus Boettcher (North-West University)

9/20/18, 11:00 AM

Oral

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.

31. The Feasibility of Magnetic Reconnection Powered Blazar Flares

Paul Morris (University of Oxford)

9/20/18, 11:30 AM

Oral + Poster

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...

5. Characterizing leptonic long-term variability in blazars

Hannes Thiersen (North-West University)

9/20/18, 11:50 AM

Oral + Poster

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)...

26. Blazars-driven beam plasma instabilities in the IGM

Dr Mohamad Shalaby

9/20/18, 12:10 PM

Oral

The TeV-bright blazars induce cosmological beam-plasma instabilities through the emission of gamma rays: The gamma rays annihilate on the infrared-ultraviolet extra-galactic background light (EBL) producing electron/positron pair-beams which drive the growth of linearly unstable beam-plasma waves during their propagation through the ionized intergalactic medium (IGM). This results in...