ChemInform Abstract: Reactions of Phosphorus Pentachloride with N,N′‐Dialkyl‐ and N‐Alkyl‐N′ ‐acetylureas.

Timokhin, B. V.; Dmitriev, V. K.; Dmitrichenko, M. Yu.; Dolgushin, G. V.

doi:10.1002/chin.199152259

Cited by 36 publications

(87 citation statements)

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“…In a previous short publication(Timokhin 2009) I presented plots similar to Figs 2 and 4 of this paper for a different cycle of the same simulation. Comparing these plots one can see that different bursts of pair formation are indeed very similar.…”

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confidence: 62%

“…This hints that current density can fluctuate because of some processes involving the whole magnetosphere (e.g. Arons 1983;Timokhin 2010). Cascades can adjust to any reasonable current density, and so the current density at a fixed colatitude might vary on time-scales much larger than τ 1 , τ 2 ; on the other hand, the current density varies across the pulsar polar cap anyway.…”

Section: Discussionmentioning

confidence: 99%

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Time-dependent pair cascades in magnetospheres of neutron stars - I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface

Timokhin¹

2010

Monthly Notices of the Royal Astronomical Society

182

139

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I argue that the problem of electromagnetically driven electron–positron cascades in magnetospheres of neutron stars must be addressed starting from first principles. I describe a general numerical algorithm for doing self‐consistent kinetic simulations of electron–positron cascades – wherein particle acceleration, pair creation and screening of the electric field are calculated simultaneously – and apply it to model the Ruderman & Sutherland cascade in one dimension. I find that pair creation is quite regular and quasi‐periodic. In each cycle a blob of ultra‐relativistic electron–positron plasma is generated; it propagates into the magnetosphere leaving a tail of less relativistic plasma behind, and the next discharge occurs when this mildly relativistic plasma leaves the polar cap. A short burst of pair formation is followed by a longer quiet phase when accelerating electric field is screened and no pairs are produced. Some of freshly injected electron–positrons pairs get trapped in plasma oscillations creating a population of low‐energy particles. The cascade easily adjusts to the current density required by the pulsar magnetosphere by reversing some of the low‐energy particles. Each discharge generates a strong coherent superluminal electrostatic wave, which may be relevant for the problem of pulsar radioemission.

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confidence: 62%

Section: Discussionmentioning

confidence: 99%

Time-dependent pair cascades in magnetospheres of neutron stars - I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface

Timokhin¹

2010

Monthly Notices of the Royal Astronomical Society

182

139

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“…Some of the particles that make up the return currents (those that are accelerated in the current sheet) are responsible for the pulsar's γ-ray and nonthermal X-ray emission Philippov & Spitkovsky 2018). The polar cap pair cascades that take place in both outgoing and return current regions (Timokhin & Arons 2013) supply pairs for radio emission. Some of the particles produced in these pair cascades are accelerated downward and are expected to deposit energy deep in the neutron star's atmosphere (see Tsai 1974 andBogdanov et al 2007).…”

Section: Modeling the Emission From The Stellar Surfacementioning

confidence: 99%

PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter

Miller

Lamb

Dittmann

et al. 2019

ApJL

1,467

1,162

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Neutron stars are not only of astrophysical interest, but are also of great interest to nuclear physicists because their attributes can be used to determine the properties of the dense matter in their cores. One of the most informative approaches for determining the equation of state (EoS) of this dense matter is to measure both a star's equatorial circumferential radius R e and its gravitational mass M . Here we report estimates of the mass and radius of the isolated 205.53 Hz millisecond pulsar PSR J0030+0451 obtained using a Bayesian inference approach to analyze its energy-dependent thermal X-ray waveform, which was observed using the Neutron Star Interior Composition Ex-Corresponding author: M. C. Miller miller@astro.umd.edu a Einstein Fellow arXiv:1912.05705v1 [astro-ph.HE] 12 Dec 2019 Miller, Lamb, Dittmann, et al. plorer (NICER). This approach is thought to be less subject to systematic errors than other approaches for estimating neutron star radii. We explored a variety of emission patterns on the stellar surface. Our best-fit model has three oval, uniform-temperature emitting spots and provides an excellent description of the pulse waveform observed using NICER. The radius and mass estimates given by this model are R e = 13.02 +1.24 −1.06 km and M = 1.44 +0.15 −0.14 M (68%). The independent analysis reported in the companion paper by Riley et al. explores different emitting spot models, but finds spot shapes and locations and estimates of R e and M that are consistent with those found in this work. We show that our measurements of R e and M for PSR J0030+0451 improve the astrophysical constraints on the EoS of cold, catalyzed matter above nuclear saturation density.

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“…Solutions of the global force-free (FF) pulsar magnetosphere (Contopoulos et al 1999;Spitkovsky 2006) require specific current patterns that depend on magnetic inclination angle (Bai & Spitkovsky 2010;Timokhin & Arons 2013). These current patterns are not uniform across the polar cap; thus, hot regions have shapes that are more complex than circles or ovals.…”

Section: Introductionmentioning

confidence: 99%

A NICER View of PSR J0030+0451: Evidence for a Global-scale Multipolar Magnetic Field

Bilous

Watts

Harding

et al. 2019

ApJL

155

122

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Recent modeling of NICER observations of thermal X-ray pulsations from the surface of the isolated millisecond pulsar PSR J0030+0451 suggests that the hot emitting regions on the pulsar's surface are far from antipodal, which is at odds with the classical assumption that the magnetic field in the pulsar magnetosphere is predominantly that of a centered dipole. Here, we review these results and examine previous attempts to constrain the magnetospheric configuration of PSR J0030+0451. To the best of our knowledge, there is in fact no direct observational evidence that PSR J0030+0451's magnetic field is a centered dipole. Developing models of physically motivated, non-canonical magnetic field configurations and the currents that they can support poses a challenging task. However, such models may have profound implications for many aspects of pulsar research, including pulsar braking, estimates of birth velocities, and interpretations of multi-wavelength magnetospheric emission.

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ChemInform Abstract: Reactions of Phosphorus Pentachloride with N,N′‐Dialkyl‐ and N‐Alkyl‐N′ ‐acetylureas.

Cited by 36 publications

References 0 publications

Time-dependent pair cascades in magnetospheres of neutron stars - I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface

Time-dependent pair cascades in magnetospheres of neutron stars - I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface

PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter

A NICER View of PSR J0030+0451: Evidence for a Global-scale Multipolar Magnetic Field

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