scholarly journals Coherent Emission in AGN: A Critique

2002 ◽  
Vol 19 (1) ◽  
pp. 34-38 ◽  
Author(s):  
D. B. Melrose
Keyword(s):  
Proton Synchrotron ◽  
Synchrotron Emission ◽  
Inverse Compton ◽  
Coherent Emission ◽  
Severe Limit ◽  
Conventional Limit

AbstractThe inverse Compton (IC) limit, TB1012 K, on synchrotron sources places a severe limit on models for intraday variables. The conventional limit is relaxed for proton synchrotron emission, or when acceleration balances IC losses. Coherent emission avoids the limit entirely but introduces other difficulties that have been inadequately discussed.

scholarly journals Extended Jets of AGN: Proton Synchrotron Emission

2017 ◽  
Author(s):  
Nayantara Gupta ◽  
Partha Pratim Basumallick
Keyword(s):  
Proton Synchrotron ◽  
Synchrotron Emission

scholarly journals Structure and Emission of Parsec-Scale Jets in Quasars

1994 ◽  
Vol 159 ◽  
pp. 257-260
Author(s):  
Max Camenzind
Keyword(s):  
Synchrotron Emission ◽  
Relativistic Jets ◽  
Poynting Flux ◽  
The Core ◽  
Magnetic Surfaces ◽  
Inverse Compton ◽  
Shafranov Equation ◽  
Γ Rays ◽  
Jet Structure ◽  
A Current

The moving knots observed in VLBI of compact quasars are due to off-axis substructures in the parsec-scale jets which are dragged along by the underlying plasma flow. This is suggested by detailed MHD models for the structure of relativistic jets on the parsec–scale that are based on exact solutions of the nonlinear Grad–Schlüter–Shafranov equation in the asymptotic domain. These jet models are characterized by a current–carrying core and a current–free envelope. The corresponding core–radius Rc = upRL is related to the poloidal jet velocity up and the light cylinder radius RL generated by the rotation of the magnetic surfaces. The Poynting flux, which has an inhomogeneous distribution in the jet, provides an off–axis energy reservoir that could be tapped and converted into particle acceleration by non-axisymmetric instabilities in the core–jet structure. Evidence is presented that quasi-periodic synchrotron emission (in the IR–optical) and inverse Compton emission (in X– and γ–rays) from freshly accelerated electrons are due to a lighthouse effect of the rotating knots.

scholarly journals Pulsar Optical Emission as Amplified Synchrotron Emission

1981 ◽  
Vol 95 ◽  
pp. 235-238
Author(s):  
R. J. Stoneham
Keyword(s):  
Optical Emission ◽  
Position Angle ◽  
Main Pulse ◽  
Synchrotron Emission ◽  
Crab Pulsar ◽  
Pulse Profile ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Linearly Polarized ◽  
Long Time

Pulsed optical emission has been observed from the Crab and Vela pulsars (Manchester and Taylor 1977). The pulse profile of the Crab pulsar has a main pulse and a strong interpulse separated by about 40% of the pulsar period; the peak of the main pulse is just resolved at 20 μs resolution; the spectrum is peaked at about 1014.8 Hz; the pulse profile is constant over long time intervals; both the main pulse and the interpulse are strongly linearly polarized with position angle varying smoothly through each profile and with a minimum of polarization near each peak; the pulses are not significantly circularly polarized. A number of models have been proposed to explain the optical emission from the Crab pulsar but none is completely satisfactory. The spectral peak is too low for incoherent synchrotron emission, the pulse profile is too constant for inverse Compton scattering of radio emission and the similarity with the low-energy X-ray emission argues against coherent curvature emission.

scholarly journals Physics of Magnetized Accretion Disks in AGN

1994 ◽  
Vol 159 ◽  
pp. 480-481
Author(s):  
George Field ◽  
Robert Rogers
Keyword(s):  
Magnetic Field ◽  
Compton Scattering ◽  
Accretion Disks ◽  
Radiation Pressure ◽  
Synchrotron Emission ◽  
Inverse Compton Scattering ◽  
Nonthermal Radiation ◽  
Field Parallel ◽  
Inverse Compton

Field and Rogers (1993) proposed that the accretion disks in moderate - L AGN (≲ 1044 erg sec−1) are dominated by magnetic stress rather than gas or radiation pressure. A magnetic field parallel to the disk forms loops above and below it where reconnection accelerates electrons to relativistic energies. The nonthermal radiation observed is the synchrotron emission and inverse-Compton scattering by these electrons.

scholarly journals A lepto-hadronic model for the high energy emission from the jets of FR I radiogalaxies

2010 ◽  
Vol 6 (S275) ◽  
pp. 168-169
Author(s):  
Matías M. Reynoso ◽  
María C. Medina ◽  
Gustavo E. Romero
Keyword(s):  
Steady State ◽  
High Energy ◽  
Inelastic Collisions ◽  
Proton Synchrotron ◽  
Relativistic Jets ◽  
Particle Distributions ◽  
Compact Region ◽  
Inverse Compton ◽  
High Energy Emission ◽  
Hadronic Model

AbstractWe present a lepto-hadronic model for the VHE emission from the relativistic jets of FR I radiogalaxies. We assume that protons and electrons are accelerated in a compact region near the base of the jet, and they cool emitting multiwavelength radiation as they propagate along the jet. The particle distributions are obtained using an inhomogeneous steady-state transport equation that accounts for the cooling processes as well as the convection of particles in the jet. The dominant processes that contribute to the photon SED are electron and proton synchrotron radiation, inverse Compton interactions, and the inelastic collisions pp and pγ. The accompanying neutrino output is obtained and the possibility of detection with Km3Net and IceCube is discussed for the cases of Cen A and M87.

scholarly journals Slugs and Snails and Puppy Dog Tails: jets from an unconventional angle

2014 ◽  
Vol 10 (S313) ◽  
pp. 199-207
Author(s):  
D. E. Harris
Keyword(s):  
Short Review ◽  
Active Galaxies ◽  
Electromagnetic Spectrum ◽  
Synchrotron Emission ◽  
X Rays ◽  
Current Experiment ◽  
Massive Black Holes ◽  
Extragalactic Jets ◽  
Inverse Compton ◽  
A Current

AbstractWe discuss some aspects of extragalactic jets originating from super massive black holes in the centres of active galaxies (and quasars). We start with a short review of sizes and flavors and then argue that the emission we detect across the electromagnetic spectrum does not come from the essence of the jet, but is rather a product of the jet. We go on to discuss some topics concerning synchrotron emission from jets, mainly aspects of knots. Finally we discuss the emission processes for the X-rays and describe a current experiment with LOFAR designed to test a requirement of inverse Compton models.

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