Conveners
Young Scientists' Session: Astrophysical jets
- Martin Pohl (DESY)
Active galactic nuclei show in their spectra broad-emission lines that are considered to be created by clouds orbiting close to the central black hole. The motion of these clouds is predominantly Keplerian, consistent with the scenario described by the Failed Radiatively Accelerated Dusty Outflow (FRADO; Czerny & Hryniewicz 2011). In this talk, we discuss the non-thermal signatures that can...
Gamma-ray-emitting narrow-line Seyfert 1 galaxies (NLS1) constitute an intriguing small population of Active Galactic Nuclei (AGN) with debated fundamental properties, unexpected gamma-ray emission and anomalous variability features, possessing properties similar to low power flat-spectrum radio quasars (FSRQ). They are jetted, gamma/radio-loud Seyfert galaxies, with relatively low BH masses,...
Hadronic interactions in cosmic-ray propagation can produce charged and neutral pions. The neutron pion decays into photons, while positrons and electrons are produced due to the decay of charged pions. The basic mechanisms that can produce gamma-ray fluxes associated with jets of cosmic rays are the decay of neutral pions electron/positron bremsstrahlung, and inverse Compton scattering. These...
The recent very-high-energy (VHE) gamma-ray observations of gamma-ray bursts (GRBs) in their afterglow phase motivate a review of the established fireball model in which a relativistic blast wave accelerates electrons in the forward shock, which then radiate via the synchrotron process and inverse Compton scattering on these synchrotron photons (synchrotron self-Compton). We use the rich...
A small fraction of GRBs with available data down to soft X-rays ( ~0.5 keV) have been shown to feature a spectral break in the low energy part of their prompt emission spectrum. The overall spectral shape is consistent with optically thin synchrotron emission from a population of marginally fast cooling particles. In this work we firstly consider that the radiating particles are hadrons and...
Multi-wavelength flux variabilities observed in relativistic jets are most often attributed to the diffusive acceleration of a population of relativistic electrons on internal shocks. The shortest observed variability time scale changes over several orders of magnitude between the radio and X-ray band. We simulate relativistic jets with the SR-HD code AMRVAC. Non-thermal particle distributions...
Ultrahigh energy cosmic rays (UHECRs) are probably originated from extragalactic sources as, e.g., Starburst, Radio Galaxies, and Active Galactic Nuclei (AGNs). In the present work, we obtain the upper limits of the cosmic-rays luminosity of Starburst galaxies. The method described in (Supanitsky 2013 and Anjos 2014) is a productive tool for the obtainment of the upper limits of the...
