Magnetic Driving of Relativistic Outflows in Active Galactic Nuclei. I. Interpretation of Parsec-Scale Accelerations

By Nektarios Vlahakis, A. Königl. 2003

179 citations recorded by the source corpus.

There is growing evidence that relativistic jets in active galactic nuclei undergo extended (parsec-scale) acceleration. We argue that, contrary to some suggestions in the literature, this acceleration cannot be purely hydrodynamic. Using exact semianalytic solutions of the relativistic MHD equations, we demonstrate that the parsec-scale acceleration to relativistic speeds inferred in sources such as the radio galaxy NGC 6251 and the quasar 3C 345 can be attributed to magnetic driving. Additional observational implications of this model will be explored in future papers in this series.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/198543996a60b3429ae0f490fb074a295caa8bab

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Canonical high power blazars (2009, methodology): “We consider either a constant Γ or include an acceleration phase of the kind (see e.g. Komissarov et al. 2007; Vlahakis & Königl 2004): Γ = min " Γmax, „ R 3RS «1/2 # (4) When the acceleration phase is taken into account, the jet isassumed to be parabolic in shape, becoming conical whenΓ reaches…”
Relativistic Jets in Active Galactic Nuclei (2006, methodology): “This makes sense if the jet is accelerated and collimated over an extended region [38], which probably corresponds to the span between the central engine and the core of the jet at the frequency where the self-absorption spectral turnover occurs, ~1 to 3 mm ([14],[1]).”
Kinematics of the jet in M 87 on scales of 100–1000 Schwarzschild radii (2016, methodology): “Both numerical simulations and observational evidence suggest that jet acceleration continues up to distances of 104–105 Rs from the central engine (Vlahakis & Königl 2004; Lobanov & Zensus 1996, 1999; Homan et al. 2015; Lee et al. 2008, 2016).”
Magnetic acceleration of relativistic AGN jets (2007, background): “The properties of the derived ﬁnal conﬁgurations were found to be qualitatively very similar to those of the self-similar AGN jet solutions of Vlahakis & K¨onigl (2004) and to not depend sensitively on either the imposed shape of the outer boundary or on the distribution of the injected poloidal…”
MOJAVE. X. PARSEC-SCALE JET ORIENTATION VARIATIONS AND SUPERLUMINAL MOTION IN ACTIVE GALACTIC NUCLEI (2013, background): “…some models indicate that this process is largely complete with the conversion of Poynting flux to flow energy on sub-pc scales (e.g., Sikora et al. 2005), there may still be significant magnetic (Vlahakis & Königl 2004) or hydrodynamic acceleration which extends to parsec or decaparsec scales.”
Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the Very Long Baseline Array (2005, methodology): “Alternatively, the acceleration could be physical, caused by considerably higher energy density in relativistic particles than in rest mass (Daly & Marscher 1988) or magnetic acceleration (Vlahakis & Königl 2004).”
Magnetic acceleration of ultrarelativistic jets in gamma-ray burst sources (2008, background): “They found that the numerical solutions assumed a quasi-static configuration that was qualitatively in accord with the self-similar AGN jet models of Vlahakis & Königl (2004).”
Are Quasar Jets Dominated by Poynting Flux? (2005, background): “…regard as somewhat premature the claims that two “accelerating” individual features, in 3C 279 (Piner et al. 2003) and 3C 345 (Unwin et al. 1997; Lobanov & Zensus 1999), respectively, prove the magnetic domination of parsec-scale jets in these objects as asserted e.g. by (Vlahakis & Königl 2004).”
Three-dimensional magnetohydrodynamic simulations of the Crab nebula (2013, background): “…of magnetic energy into the bulk motion energy of particles is less of an issue for collimated jets than for uncollimated pulsar winds (e.g. Vlahakis & Königl 2004; Komissarov et al. 2007; Tchekhovskoy, Narayan & McKinney 2010; Lyubarsky 2009), it is still quite impossible to reach σ <…”
FLARING BEHAVIOR OF THE QUASAR 3C 454.3 ACROSS THE ELECTROMAGNETIC SPECTRUM (2010, methodology): “In the ACZ, Poynting flux is converted to bulk kinetic energy through the Lorentz force, which rotates the MHD outflows and forms helical trajectories of disturbances propagating down the jet (Vlahakis & Königl 2004; Vlahakis 2006; Komissarov et al. 2007).”
PROBING THE INNER JET OF THE QUASAR PKS 1510−089 WITH MULTI-WAVEBAND MONITORING DURING STRONG GAMMA-RAY ACTIVITY (2010, background): “4) is due to an increasing Doppler factor as the flow accelerates until it reaches the core, since the Lorentz factor increases as the cross-sectional radius of the jet (Vlahakis & Königl 2004; Vlahakis 2006; Komissarov et al. 2007).”
Magnetic field strength and spectral distribution of six parsec-scale active galactic nuclei jets (2009, background): “…regions are distinguishing characteristics of magnetohydrodynamic (MHD) dominated flows over purely hydrodynamical ones, and uses E-mail: shaneosullivan@phys.ucc.ie the model of Vlahakis & Königl (2004) to explain the parsec-scale acceleration of component C7 of 3C 345 (Unwin et al. 1997).”
Multiwaveband Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Correlated Polarization Behavior (2007, methodology): “The twisted field propagates outward as Poynting flux in the polar directions, with eventual conversion into a well-focused relativistic plasma flow (e.g., Vlahakis & Königl 2004; Meier & Nakamura 2006).”
MOJAVE: Monitoring of Jets in Active galactic nuclei with VLBA Experiments (2012, background): “As discussed by Vlahakis & Königl (2004), a poloidaldominated magnetic field embedded in the accretion disk or in the black hole ergosphere is wound-up into toroidal loops that may provide effective jet collimation via hoop stress and accelerate the flow by magnetic pressure gradient up to a…”
General physical properties of bright Fermi blazars (2009, background): “In the acceleration region the jet is parabolic (following, e.g. Vlahakis & Königl 2004) and beyond this point the jet becomes conical with a semi–aperture angleψ (assumed to be 0.1 for all sources).”