Electrodynamics of Magnetars III: Pair Creation Processes in an Ultrastrong Magnetic Field and Particle Heating in a Dynamic Magnetosphere
arXiv:0802.2571 · doi:10.1086/592263
Abstract
We consider the details of the QED processes that create electron-positron pairs in magnetic fields approaching and exceeding 10^{14} G. The formation of free and bound pairs is addressed, and the importance of positronium dissociation by thermal X-rays is noted. We calculate the collision cross section between an X-ray and a gamma ray, and point out a resonance in the cross section when the gamma ray is close to the threshold for pair conversion. We also discuss how the pair creation rate in the open-field circuit and the outer magnetosphere can be strongly enhanced by instabilities near the light cylinder. When the current has a strong fluctuating component, a cascade develops. We examine the details of particle heating, and show that a high rate of pair creation can be sustained close to the star, but only if the spin period is shorter than several seconds. The dissipation rate in this turbulent state can easily accommodate the observed radio output of the transient radio-emitting magnetars, and even their infrared emission. Finally, we outline how a very high rate of pair creation on the open magnetic field lines can help to stabilize a static twist in the closed magnetosphere and to regulate the loss of magnetic helicity by reconnection at the light cylinder.
arXiv comment25 pages, submitted to the Astrophysical Journal
References in corpus (44)
- Time-dependent force-free pulsar magnetospheres: axisymmetric and oblique rotators
- Electrodynamics of Magnetars: Implications for the Persistent X-ray Emission and Spindown of the Soft Gamma Repeaters and Anomalous X-ray Pulsars
- An exceptionally bright flare from SGR1806-20 and the origins of short-duration gamma-ray bursts
- Transient pulsed radio emission from a magnetar
- Gravitational Waves from Neutron Stars with Large Toroidal B-fields
- Corona of Magnetars
- 1E 1547.0-5408: a radio-emitting magnetar with a rotation period of 2 seconds
- Discovery of luminous pulsed hard X-ray emission from anomalous X-ray pulsars 1RXS J1708-4009, 4U 0142+61 and 1E 2259+586 by INTEGRAL and RXTE
- Changes in the X-ray Emission from the Magnetar Candidate 1E 2259+586 during its 2002 Outburst
- Magnetar Spin-Down
- Radio Quiet Pulsars with Ultra-Strong Magnetic Fields
- Resonant Cyclotron Scattering and Comptonization in Neutron Star Magnetospheres
- Discovery of hard non-thermal pulsed X-ray emission from the anomalous X-ray pulsar 1E 1841-045
- Pair-production multiplicities in rotation-powered pulsars
- Revised Pulsar Spindown
- Photon Splitting and Pair Creation in Highly Magnetized Pulsars
- Pair Multiplicities and Pulsar Death
- Physical Mechanisms for the Variable Spin-down of SGR 1900+14
- The Prelude to and Aftermath of the Giant Flare of 2004 December 27: Persistent and Pulsed X-ray Properties of SGR 1806-20 from 1993 to 2005
- The magnetar 1E 1547.0-5408: radio spectrum, polarimetry, and timing
- Magnetars as persistent hard X-ray sources: INTEGRAL discovery of a hard tail in SGR 1900+14
- Distances to Anomalous X-ray Pulsars using Red Clump Stars
- High Energy Emission from Magnetars
- The magnetar XTE J1810-197: variations in torque, radio flux density and pulse profile morphology
- Resonant Cyclotron Scattering in Three Dimensions and the Quiescent Non-thermal X-ray Emission of Magnetars
- Deceleration of a Relativistic, Photon-Rich Shell: End of Preacceleration, Damping of MHD Turbulence, and the Emission Mechanism of Gamma-Ray Bursts
- Resonant Compton Upscattering in Anomalous X-ray Pulsars
- Condensed Surfaces of Magnetic Neutron Stars, Thermal Surface Emission, and Particle Acceleration Above Pulsar Polar Caps
- Polarized radio emission from a magnetar
- Large Torque Variations in Two Soft Gamma Repeaters
- INTEGRAL discovery of persistent hard X-ray emission from the Soft Gamma Ray Repeater SGR 1806-20
- Magnetospheric Eclipses in the Binary Pulsar J0737-3039
- XMM-Newton observations of the Galactic Supernova Remnant CTB 109 (G109.1-1.0)
- The Spectral Evolution of Transient Anomalous X-ray Pulsar XTE J1810--197
- Fading of the Transient Anomalous X-ray Pulsar XTE J1810-197
- X-ray and Near-IR Variability of the Anomalous X-ray Pulsar 1E 1048.1-5937: From Quiescence Back to Activity
- Long-Term RXTE Monitoring of the Anomalous X-ray Pulsar 1E 1048.1-5937
- Extinction Columns and Intrinsic X-ray Spectra of the Anomalous X-ray Pulsars
- Electron Energy Losses Near Pulsar polar Caps
- Photoionization of hydrogen in atmospheres of magnetic neutron stars
- Spin-Dependent Cyclotron Decay Rates in Strong Magnetic Fields
- Electrodynamics of Magnetars IV: Self-Consistent Model of the Inner Accelerator, with Implications for Pulsed Radio Emission
- Photon Splitting in the Superstrong Magnetic Fields of Pulsars
- Implications of the Narrow Period Distribution of Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters
Cited by in corpus (26)
- The Proto-Magnetar Model for Gamma-Ray Bursts
- A model for fast extragalactic radio bursts
- Magnetars: the physics behind observations
- Fast radio bursts from reconnection in magnetar magnetosphere
- Electron-positron flows around magnetars
- Pair cascades in the magnetospheres of strongly-magnetized neutron stars
- The fundamental plane for radio magnetars
- Multi-wavelength Observations of the Radio Magnetar PSR J1622-4950 and Discovery of its Possibly Associated Supernova Remnant
- Global Crustal Dynamics of Magnetars in Relation to their Bright X-ray Outbursts
- The X-Ray Polarization Signature of Quiescent Magnetars: Effect of Magnetospheric Scattering and Vacuum Polarization
- Heavy Nuclei Synthesized in Gamma-Ray Burst Outflows as the Source of UHECRs
- Simultaneous multi-frequency single-pulse properties of AXP XTE J1810-197
- An Energetic Magnetar in HESS J1713-381/CTB 37B
- Electrodynamics of Magnetars IV: Self-Consistent Model of the Inner Accelerator, with Implications for Pulsed Radio Emission
- Thermally-induced vacuum instability in a single plane wave
- QED Phenomena in an Ultrastrong Magnetic Field. I. Electron-Photon Scattering, Pair Creation, and Annihilation
- Spin-polarization effects in the processes of synchrotron radiation and electron-positron pair production by a photon in a magnetic field
- Pair Plasma in Super-QED Magnetic Fields and the Hard X-ray/Optical Emission of Magnetars
- Direct Emission of Strong Radio Pulses During Magnetar Flares
- Coherent radio emission from a twisted magnetosphere after magnetar-quake
- Radio Emission of Pulsars. I. Slow Tearing of a Quantizing Magnetic Field
- Radio Emission of Pulsars. II. Coherence Catalyzed by Cerenkov-Unstable Shear Alfvén Waves
- Very high frequency gravitational waves from magnetars and gamma-ray burst
- A multi-component Langmuir-mode source for the observed pulsar coherent emission
- The High Frequency Radio Emission of the Galactic Center Magnetar SGR J1745-29 During a Transitional Period
- Heating of Magnetically Dominated Plasma by Alfvén-Wave Turbulence