Conveners
Formation and propagation of relativistic outflows
- Maxim Barkov (Purdue University)
Formation and propagation of relativistic outflows
- Valenti Bosch-Ramon (Universitat de Barcelona/ICCUB)
Formation and propagation of relativistic outflows
- Manel Perucho Pla (Universitat de València)
Particle acceleration in relativistic jets to very high energies occurs at the expense of the dissipation of magnetic or kinetic energy. Therefore, understanding the processes that can trigger this dissipation is key to the characterization of the energy budgets and particle acceleration mechanisms at action in active galaxies. Instabilities and entrainment are two obvious candidates to...
Plasma injection and magnetic field dissipation are two key issues in the theory of black hole jets. Pair production in either starved magnetospheric regions or dissipative boundary layers can supply the plasma required for black hole activation. These processes naturally produce rapidly
varying VHE emission. In the first part of the talk I shall discuss pair creation in a starved BH...
Fermi telescope has detected a significant number of AGNs to allow statistical treatment of their properties. Among others, it confirmed the "Blazar Divide" in FSRQs and BL Lacs according to their gamma-ray spectral index and luminosity. We investigate this classification by proposing a model which reproduces in detail the broadband blazar spectra and their statistical properties based on the...
Synchrotron origin of the radiation from extragalactic disks indicate to important role of the magnetic field in their formation and collimation. Jets from AGN show their close connection with supermassive black holes. Large magnetic fields around BH are formed during an accretion of matter with large-scale magnetic field. Approximate solutions describing such accretion lead to conclusion of...
The Event Horizon Telescope (EHT) has captured the first image of a black hole. The central compact radio source in the radio galaxy M87 has been resolved out into an asymmetric bright emission ring with a diameter of 42 uas, which is circular and encompasses a central depression in brightness with a flux ratio >10:1. The emission ring is recovered using different calibration and imaging...
Over the last two decades, general relativistic magnetohydrodynamic simulations (GRMHD) have drawn a robust theoretical picture of jet formation in low-luminosity sources. The observations by the Event Horizon Telescope now allow to test these theories at an unprecedented level. I will take this opportunity to review the state-of-the-art in 3D numerical source models. Nowadays, adaptive mesh...
The jets launched by accreting super-massive black holes can be some of the brightest sources in the high-energy sky. However, despite being discovered decades ago, their physics and energetics are still poorly understood. The past decade has seen a dramatic improvement in the quality of available multi-wavelength data, particularly in the X-ray and $\gamma$-ray bands. However, the...
Accreting black holes can eject jets that are composed of electrons, positrons and ions. Electromagnetic emissions by such jets reveal the presence of strong coherent magnetic fields, of hot plasma and relativistic leptons. Several mechanisms contribute to the magnetic field of the jet: magnetic field transport by the jet, the amplification of the ambient magnetic field by shocks and...
Extragalactic jets are launched from the innermost regions of galaxies, near the central supermassive black hole. As they propagate, they must cross the whole galaxy, and in this process they interact with a variety of obstacles; including gas clouds, populations of stars or even supernova remnants. The interaction between jets and penetrating obstacles has been studied as a possible method...
Plasma focus (PF) facilities have proved to be an effective tool in the modeling of outflows from compact astrophysical objects [1]. The specific feature of the experimental scheme with PF is the possibility to study the propagation of plasma flows over long distances, while we are able to change the parameters of the ambient medium. The talk provides a brief overview of the latest experiments...
Astrophysical jets from AGNs and microquasars are often relativistic and collimated. We study magnetic and radiative driving of jets to address these issues. The plasma is described by relativistic equation of state which depends on the composition. We show that the matter content may not affect the streamline of magnetically driven jets, but the poloidal velocity and temperature distribution...
In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the evolution of both electron–proton and electron–positron relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of “global” jets containing helical magnetic fields...
