Conveners
Modeling
- Andrew Taylor
Modeling
- Andrew Taylor
Modeling
- Fabrizio Tavecchio
-
Dr Martin Lemoine (Institut d'Astrophysique de Paris)23/01/2019, 14:00Main trackTalkThe acceleration of charged particles to high energies in powerful astrophysical sources such as blazars represents a central question in modern multi-messenger astrophysics. Accelerated particles can interact with and radiate in ambient fields to produce secondary photon or neutrino fluxes, or escape from the source to become part of the cosmic ray spectrum. This presentation will discuss...Go to contribution page
-
Dr Andreas Zech (LUTH, Observatoire de Paris)23/01/2019, 14:40Main trackTalkThe emerging class of extreme blazars, characterised by very hard high-energy spectra peaking around TeV energies, pose a challenge for the usual blazar emission models. While the multi-wavelength emission from high-frequency BL Lac type blazars can in generally be well interpreted with the single-zone SSC model, the very hard spectra of extreme blazars (or “ultra-high frequency peaked...Go to contribution page
-
Mr Matteo Lucchini (Anton Pannekoek Institute for Astronomy)23/01/2019, 15:20Main trackTalkThe jets launched by accreting super-massive black holes can be some of the brightest sources in the high-energy sky; despite be- ing discovered decades ago, their physics and energetics are still poorly understood. The past decade has seen a dramatic improve- ment in the quality of available data, particularly in the X-ray and γ-ray bands. However, the semi-analytical modelling of jets...Go to contribution page
-
Dr Olivier Hervet (UC Santa Cruz)23/01/2019, 15:40Main trackTalkMost of the TeV high-frequency-peaked BL Lacs (HBLs) show stationary or slow motions of their VLBI radio-knots, in stark contrast with their fast variability. This problem, known as "the bulk Lorentz factor crisis," indicates that the VLBI motions of these sources are not showing the real flow propagation of the jets. I will present evidence that these stationary radio knots are recollimation...Go to contribution page
-
Ms Stella Boula (National and Kapodistrian University of Athens)23/01/2019, 16:30Main trackTalk
The launch of Fermi produced a significant number of AGN detections to allow statistical treatment of their properties. It confirmed the
Go to contribution pageBlazar Sequence" established by EGRET and indicated a potentially novel one, namely that of theBlazar Divide" in FSRQs and BL Lacs according to their gamma-ray spectral index and luminosity. An MHD accretion wind model that describes the distribution of... -
Dr Krzysztof Nalewajko (Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences)23/01/2019, 16:50Main trackTalkCompton dominance, the observed ratio between the high-energy (assumed to be due to inverse Compton) and synchrotron components of the spectral energy distributions of blazars, is an indirect probe of magnetization of their relativistic jets. For most blazars, the Compton dominance is observed in the range 0.3-10, and in the framework of one-zone leptonic models it can be explained by mildly...Go to contribution page
-
Dr Laura Di Gesu (Italian Space Agency (ASI))23/01/2019, 17:10Main trackTalk
With the advent of the IXPE (Imaging X-ray Polarimetry Explorer) satellite
Go to contribution page
expected for launch in 2021, the study of the
X-ray polarization properties of several bright nearby sources
will become possible. Blazars are obvious candidates for X-ray
polarization observations.
For instance, a high degree of X-ray polarization is expected from
high-peaked blazars (HBL) because... -
Dr Andrea Tramacere (Astronomy Department of the University of Geneva,)24/01/2019, 09:00Main trackTalkI will review some of the main phenomenological signatures of the stochastic acceleration acting in the relativistic jets of blazars. I will link predictions from Monte Carlo simulations and from the numerical solution of the diffusion equation in momentum space, to the spectral features observed in the multi-wavelength SED of blazars. In particular, I will focus on the spectral...Go to contribution page
-
Prof. Markus Boettcher (North-West University)24/01/2019, 09:20Main trackTalkDiffusive shock acceleration (DSA) at mildly relativistic shocks has been argued to be an efficient mechanism for the acceleration of ultrarelativistic particles blazar jets. Here we present results of coupled time-dependent simulations of diffusive shock acceleration and production of synchrotron and Compton emission to model the expected spectral variability signatures of shocks in...Go to contribution page
-
Dr Ian Christie (Northwestern University)24/01/2019, 09:40Main trackTalkRelativistic magnetic reconnection is a strong candidate for the acceleration of particles to high-energies and is a proposed mechanism for the multi-wavelength spectral and temporal variability observed in blazar jets. By coupling recent two-dimensional particle-in-cell simulations of relativistic reconnection with a time-dependent radiative transfer model, we compute the non-thermal emission...Go to contribution page
-
Ms Ioulia Florou (National & Kapodistrian University of Athens)24/01/2019, 10:00Main trackTalkHadronic models of high-energy AGN emission become more relevant than ever before after the latest IceCube results that associate a gamma-ray flaring AGN with high-energy neutrinos. Despite offering a unique framework for the production of high-energy neutrinos, hadronic scenarios have been criticized in the past for being radiatively inefficient. However, an overlooked property of hadronic...Go to contribution page