On the MHD effects on the force-free monopole outflow

Бескин, В. С.; Kuznetsova, Inga; Rafikov, Roman R.

doi:10.1046/j.1365-8711.1998.01659.x

Cited by 149 publications

(190 citation statements)

References 30 publications

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“…The now-robust association of long-duration GRBs with highly energetic supernovae, as evidenced by SN 1998bw 16 Analyses of ideal relativistic winds predict that 1 $ À 1=3 (Michel 1969;Goldreich & Julian 1970;Beskin et al 1998). However, modeling of the equatorial relativistic wind of the Crab pulsar (Kennel & Coroniti 1984a, 1984bSpitkovsky & Arons 2004) suggests that 1 $ À and not that 1 $ À 1=3 , in contradiction with theoretical expectations.…”

Section: Gamma-ray Burstsmentioning

confidence: 99%

Magnetar Spin‐Down, Hyperenergetic Supernovae, and Gamma‐Ray Bursts

Thompson¹,

Chang

Quataert³

2004

ApJ

386

500

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The Kelvin-Helmholtz cooling epoch, lasting tens of seconds after the birth of a neutron star in a successful core-collapse supernova, is accompanied by a neutrino-driven wind. For magnetar-strength ($10 15 G) large-scale surface magnetic fields, this outflow is magnetically dominated during the entire cooling epoch. Because the strong magnetic field forces the wind to corotate with the proto-neutron star, this outflow can significantly affect the neutron star's early angular momentum evolution, as in analogous models of stellar winds. If the rotational energy is large in comparison with the supernova energy and the spin-down timescale is short with respect to the time required for the supernova shock wave to traverse the stellar progenitor, the energy extracted may modify the supernova shock dynamics significantly. This effect is capable of producing hyperenergetic supernovae and, in some cases, provides conditions favorable for gamma-ray bursts. We estimate spin-down timescales for magnetized, rotating proto-neutron stars and construct steady state models of neutrino-magnetocentrifugally driven winds. We find that if magnetars are born rapidly rotating, with initial spin periods (P) of $1 ms, then of order 10 51 -10 52 ergs of rotational energy can be extracted in $10 s. If magnetars are born slowly rotating (P k10 ms), they can spin down to periods of $1 s on the Kelvin-Helmholtz timescale.

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Section: Gamma-ray Burstsmentioning

confidence: 99%

Magnetar Spin‐Down, Hyperenergetic Supernovae, and Gamma‐Ray Bursts

Thompson¹,

Chang

Quataert³

2004

ApJ

386

500

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“…The pressure from a poloidal magnetic field, on the other hand, can effectively confine the flow. However, an additional contribution from the external medium is necessary for preventing the terminal speed and collimation of the flow to be reached on unreasonably large scales (Tomimatsu 1994;Beskin et al 1998). In accreting systems like active galactic nuclei (AGN), this medium is likely to be the magnetized slow wind ejected by the edges of the accretion disk.…”

Section: Introductionmentioning

confidence: 99%

The stratified two-sided jet of Cygnus A

Boccardi

Krichbaum

Bach

et al. 2015

A&A

101

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Aims. High-resolution Very-Long-Baseline Interferometry (VLBI) observations of relativistic jets are essential for constraining the fundamental parameters of jet formation models. At a distance of 249 Mpc, Cygnus A is a unique target for such studies, since it is the only Fanaroff-Riley Class II radio galaxy for which a detailed subparsec scale imaging of the base of both jet and counter-jet can be obtained. Observing at millimeter wavelengths unveils those regions that appear self-absorbed at longer wavelengths and enables an extremely sharp view toward the nucleus to be obtained. Methods. We performed 7 mm Global VLBI observations, achieving ultra-high resolution imaging on scales down to 90 µas. This resolution corresponds to a linear scale of only ∼400 Schwarzschild radii (for M BH = 2.5 × 10 9 M ). We studied the kinematic properties of the main emission features of the two-sided flow and probed its transverse structure through a pixel-based analysis. Results. We suggest that a fast and a slow layer with different acceleration gradients exist in the flow. The extension of the acceleration region is large (∼10 4 R S ), indicating that the jet is magnetically driven. The limb brightening of both jet and counter-jet and their large opening angles (φ J ∼ 10 • ) strongly favour a spine-sheath structure. In the acceleration zone, the flow has a parabolic shape (r ∝ z 0.55 ± 0.07 ). The acceleration gradients and the collimation profile are consistent with the expectations for a jet in "equilibrium", achieved in the presence of a mild gradient of the external pressure (p ∝ z −k , k ≤ 2).

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“…is the magnetic flux, which is a constant of motion along a streamline (Beskin et al 1998;Bucciantini et al 2006). A Keplerian orbit is represented in polar coordinates in the orbit's plane by the equation…”

Section: Force Exerted By the Current Systemmentioning

confidence: 99%

“…The model considers the poloidal field B r to be radial and includes the selfconsistent toroidal field B φ . Other models for steady-state and axisymmetric, but not necessarily radial, winds have been developed more recently (Beskin et al 1998;Bucciantini et al 2006). Their equations admit a set of integrals of motion along stream lines, in particular, the magnetic flux Φ defined in Eq.…”

Section: Possible Location Of the Fast-mode Critical Surfacementioning

confidence: 99%

Towards a theory of extremely intermittent pulsars

Mottez¹,

Bonazzola²,

Heyvaerts³

2013

A&A

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Aims. We investigate whether one or many companions are orbiting the extremely intermittent pulsar PSR B1931+24. Methods. We constrained our analysis on previous observations of eight fundamental properties of PSR B1931+24. The most puzzling properties are the intermittent nature of the pulsar's activity, with active and quiet phases that alternate quasi-periodically; the variation of the slowing-down rate of its period between active and quiet phases; and because there are no timing residuals, it is highly unlikely that the pulsar has a massive companion. Here, we examine the effects that one putative companion immersed in the magnetospheric plasma or the wind of the pulsar might have, as well as the associated electric current distribution. We analysed several possibilities for the distance and orbit of this hypothetical companion and the nature of its interaction with the neutron star. Results. We show that if the quasi-periodic behaviour of PSR B1931+24 was caused by a companion orbiting the star with a period of 35 or 70 days, the radio emissions, usually considered to be those of the pulsar would in that specific case be emitted in the companion's environment. We analysed four possible configurations and conclude that none of them would explain the whole set of peculiar properties of PSR 1931+24. We furthermore considered a period of 70 days for the precession of the periastron associated to an orbit very close to the neutron star. This hypothesis is analysed in a companion paper.

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On the MHD effects on the force-free monopole outflow

Cited by 149 publications

References 30 publications

Magnetar Spin‐Down, Hyperenergetic Supernovae, and Gamma‐Ray Bursts

Magnetar Spin‐Down, Hyperenergetic Supernovae, and Gamma‐Ray Bursts

The stratified two-sided jet of Cygnus A

Towards a theory of extremely intermittent pulsars

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