A5082226813- Pulsars and Gravitational Waves Research
- Magnetic confinement fusion research
- Gamma-ray bursts and supernovae
- Geophysics and Sensor Technology
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Astronomy and Astrophysical Research
- Ionosphere and magnetosphere dynamics
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Earthquake Detection and Analysis
- Nuclear Materials and Properties
- Nuclear reactor physics and engineering
- Astrophysical Phenomena and Observations
- Particle accelerators and beam dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Particle Accelerators and Free-Electron Lasers
- Stellar, planetary, and galactic studies
- Nuclear Physics and Applications
- Geological and Geophysical Studies
- Galaxies: Formation, Evolution, Phenomena
- Graphite, nuclear technology, radiation studies
- Radio Astronomy Observations and Technology
Deleted Institution
2012-2020
Research & Development Institute
2020
Goddard Space Flight Center
2012-2020
University of Zielona Góra
2020
Institute of Power Engineering
2020
University of Maryland, College Park
2014-2019
George Washington University
2019
Lomonosov Moscow State University
1995-2017
Moscow State University of Environmental Engineering
2013-2016
A. N. Kosygin Moscow State Textile University
2013
We investigate in detail the properties of stationary force-free magnetosphere an aligned rotator assuming last closed field line is lying equatorial plane at large distances from pulsar. The pulsar equation solved numerically using a multigrid code with high numerical resolution, and physical are obtained accuracy. found set solutions different sizes magnetic zone verify applicability approximation. discuss role electron–positron cascades supporting argue that should grow time slower rate...
We report the results of an investigation particle acceleration and electron–positron plasma generation at low altitude in polar magnetic flux tubes rotation-powered pulsars, when stellar surface is free to emit whatever charges currents are demanded by force-free magnetosphere. apply a new 1D hybrid simulation code dynamical problem, using Particle-in-Cell methods for dynamics charged particles, including determination collective electrostatic fluctuations plasma, combined with Monte Carlo...
I argue that the problem of electromagnetically driven electron–positron cascades in magnetospheres neutron stars must be addressed starting from first principles. describe a general numerical algorithm for doing self-consistent kinetic simulations – wherein particle acceleration, pair creation and screening electric field are calculated simultaneously apply it to model Ruderman & Sutherland cascade one dimension. find is quite regular quasi-periodic. In each cycle blob ultra-relativistic...
Abstract We analyze the statistics of pulse arrival times in fast radio burst (FRB) 121102 and demonstrate that they are remarkably similar to magnetar high-energy short bursts. Motivated by this correspondence, we propose repeating FRBs generated during bursts closed field line zone magnetospheres via a pulsar-like emission mechanism. Crustal slippage events dislocate foot points, initiating intense particle acceleration pair production, giving rise coherent near pulsar polar caps. argue...
We present 3D global kinetic pulsar magnetosphere models, where the charged particle trajectories and corresponding electromagnetic fields are treated self-consistently. For our study, we have developed a cartesian relativistic particle-in-cell code that incorporates radiation reaction forces. describe discuss related technical issues, treatments, assumptions. Injecting particles up to large distances in magnetosphere, apply arbitrarily low high injection rates get an entire spectrum of...
Since pulsars were discovered as emitters of bright coherent radio emission more than half a century ago, the cause has remained mystery. In this Letter we demonstrate that radiation can be directly generated in nonstationary pair plasma discharges which are responsible for filling pulsar magnetosphere with plasma. By means large-scale two-dimensional kinetic simulations, show if creation is nonuniform across magnetic field lines, screening electric by freshly produced accompanied waves...
We propose that in some pulsars the magnetosphere has different states with geometries or/and distributions of currents, it occasionally switches between them. These have spindown rates and emission beams, no radioemission is produced at all. Switching into a state manifests as mode change when we see parts beam or beams significantly geometries, nulling either miss new generated state. show modest variations shape can be accompanied by large pulsar rate W - dependence on opening angle $α$...
We performed ab-initio Particle-In-Cell (PIC) simulations of a pulsar magnetosphere with electron-positron plasma produced only in the regions close to neutron star surface. study how transitions from vacuum nearly force-free configuration. compare resulting like configuration ones obtained PIC simulation where particles are injected everywhere as well macroscopic simulations. found that although both solutions have similar structure electromagnetic fields and current density distributions,...
We study the efficiency of pair production in polar caps young pulsars under a variety conditions to estimate maximum possible multiplicity plasma pulsar magnetospheres. develop semi-analytic model for calculation cascade which allows efficient exploration parameter space and corroborate it with direct numerical simulations. Pair creation processes are considered separately from particle acceleration order assess different factors affecting efficiency, primary particles described by recent...
Results of simultaneous INTEGRAL and optical observations the galactic microquasar SS433 in May 2003 /RXTE March 2004 are presented. Persistent precessional variability with a maximum to minimum uneclipsed hard X-ray flux ratio ∼4 is discovered. The 18–60 keV eclipse found be phase near infrared eclipses. orbital observed by at least two times deeper apparently wider than soft band. broadband 2–100 spectrum simultaneously detected RXTE/INTEGRAL can explained bremsstrahlung emission from...
Abstract We study electron–positron pair production in polar caps of energetic pulsars to determine the maximum multiplicity plasma a pulsar can produce under most favorable conditions. This paper complements and updates our cascades presented Timokhin & Harding (2015) with more accurate treatment effects ultrastrong <?CDATA $B\gtrsim 3\times {10}^{12}$?> G magnetic fields emission processes primary secondary particles. include pairs produced by curvature synchrotron radiation photons as...
We explore the burst energy distribution of fast radio bursts (FRBs) in low-twist magnetar model Wadiasingh and Timokhin (2019). Motivated by power-law fluence distributions FRB 121102, we propose an elementary for luminosity function individual repeaters with inversion protocol which directly relates index short fluences to that FRBs. The indicates scales virtually linearly crust/field dislocation amplitude, if prevail magnetoelastic regime. Charge starvation magnetosphere during (required...
The spectra of very high energy γ-radiation from distant extragalactic objects suffer significant deformations during the passage primary γ-rays through intergalactic medium. recently reported fluxes diffuse infrared background radiation indicate that we detect, most probably, heavily absorbed TeV Mkn 421 and 501. This implies absorption-corrected spectrum 501 may contain a sharp pile-up which contradicts to predictions conventional models blazars, thus lead so-called “IR background-TeV...
A model is presented for the quasiperiodic component of magnetar emission during tail phase giant flares. The invokes modulation particle number density in magnetosphere. magnetospheric currents are modulated by torsional motion surface and we calculate that amplitude neutron star oscillation should be ~1% NS radius order to produce observed features power spectrum. Using an axisymmetric analytical structure magnetosphere oscillating NS, angular distribution optical depth resonant Compton...
We derive the exact drift velocity of plasma in pulsar polar cap, contrast to order-of-magnitude expressions presented by Ruderman & Sutherland (1975) and generally used throughout literature. emphasize that depends not on absolute value, as is used, but variation accelerating potential across cap. If we assume drifting subpulses pulsars are indeed due this drift, several observed subpulse-drift phenomena incompatible with family models can now be explained: show variations rate, outright...
Pulsar radio emission may be generated in pair discharges which fill the pulsar magnetosphere with plasma as an accelerating electric field is screened by freshly created pairs. In this Letter we develop a simplified analytic theory for screening of these and use it to estimate total luminosity spectrum. The discharge has three stages. First, first time starts oscillate. Next, nonlinear phase occurs. phase, amplitude experiences strong damping because dramatically changes momenta newly This...
The origin of the non-thermal EUV and hard X-ray emission "excess" reported from some galaxy clusters has been intensively debated over last several years. most favored models which refer this excess to relativistic electrons upscattering 2.7 K Cosmic Microwave Background Radiation (CMBR) generally requires a very low magnetic field, significantly below estimates derived Faraday Rotation Measurements, unless one invokes rather nonstandard assumptions concerning energy pitch angle...
We generalize a formula for the Goldreich–Julian charge density (ρGJ), originally derived rotating neutron star, arbitrary oscillations of star with an magnetic field configuration under assumption low current in inner parts magnetosphere. As application, we consider toroidal oscillation dipole and calculate energy losses. For some modes, longitudinal electric cannot be cancelled by putting charged particles magnetosphere without presence strong (j≃ρGJc×cωr). It is shown that losses are...
Global-scale solutions for the magnetosphere of a pulsar consist region low-lying, closed magnetic field near star, bounded by opposite-polarity regions open along which wind flows into space. Separating these open-field is discontinuity—an electric current sheet—consisting generally nonneutral plasma. We have developed self-consistent model internal equilibrium structure sheet generalizing charge–neutral Vlasov/Maxwell equilibria Harris and Hoh to allow net charge. The resulting equations...
In this paper we consider the stationary force-free magnetosphere of an aligned rotator when plasma in open field-line region rotates differentially as a result presence zone with accelerating electric field polar cap pulsar. We study impact differential rotation on current density distribution magnetosphere. Using split-monopole approximation obtain analytical expressions for physical parameters rotating find range admitted distributions under requirement that potential drop is less than...
Pair cascades in polar cap regions of neutron stars are considered to be an essential process various models coherent radio emissions pulsars. The produce pair plasma bunch discharges quasi-periodic spark events. cascade properties, and therefore also the radiation, depend strongly on magnetospheric properties vary significantly across along cap. It is furthermore still uncertain from where emission emanates region. We investigate generation electromagnetic waves by their propagation for...
Pair cascades in polar cap regions of neutron stars are considered to be an essential process various models coherent radio emissions pulsars. The produce pair plasma bunch discharges quasi-periodic spark events. cascade properties, and therefore also the radiation, depend strongly on magnetospheric properties vary significantly across along cap. Importantly, where emission emanates from region is still uncertain. We investigate generation electromagnetic waves by their propagation for three...