Millisecond pulsars with extremely strong magnetic fields as a cosmological source of γ-ray bursts

Усов, В. В.

doi:10.1038/357472a0

Cited by 958 publications

(569 citation statements)

References 26 publications

Supporting

Mentioning

558

Contrasting

Unclassified

Order By: Relevance

“…At the opposite extreme from MSPs, anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) appear to be NSs with magnetic fields above the QED critical field BQED = 4.4 × 10 13 G (Mereghetti 2013), most commonly described by the magnetar model (Duncan & Thompson 1992;Paczynski 1992;Usov 1992). The lack of persistent radio emission above 500 MHz (Istomin & Sobyanin 2007;Lazarus et al 2012) and the transient, highly-variable radio emission observed from a subset of these objects (Camilo et al 2007;Malov 2014) suggests that the density of plasma in the magnetospheres of magnetars is lower than in normal radio pulsars (Istomin & Sobyanin 2007;Malov 2014).…”

Section: Discussionmentioning

confidence: 99%

Frequency-dependent effects of gravitational lensing within plasma

Rogers

2015

Monthly Notices of the Royal Astronomical Society

124

120

View full text Add to dashboard Cite

The interaction between refraction from a distribution of inhomogeneous plasma and gravitational lensing introduces novel effects to the paths of light rays passing by a massive object. The plasma contributes additional terms to the equations of motion, and the resulting ray trajectories are frequency-dependent. Lensing phenomena and circular orbits are investigated for plasma density distributions N ∝ 1/r h with h ≥ 0 in the Schwarzschild space-time. For rays passing by the mass near the plasma frequency refractive effects can dominate, effectively turning the gravitational lens into a mirror. We obtain the turning points, circular orbit radii, and angular momentum for general h. Previous results have shown that light rays behave like massive particles with an effective mass given by the plasma frequency for a constant density h = 0. We study the behaviour for general h and show that when h = 2 the plasma term acts like an additional contribution to the angular momentum of the passing ray. When h = 3 the potential and radii of circular orbits are analogous to those found in studies of massless scalar fields on the Schwarzschild background. As a physically motivated example we study the pulse profiles of a compact object with antipodal hotspots sheathed in a dense plasma, which shows dramatic frequency-dependent shifts from the behaviour in vacuum. Finally, we consider the potential observability and applications of such frequency-dependent plasma effects in general relativity for several types of neutron star.

show abstract

Section: Discussionmentioning

confidence: 99%

Frequency-dependent effects of gravitational lensing within plasma

Rogers

2015

Monthly Notices of the Royal Astronomical Society

124

120

View full text Add to dashboard Cite

show abstract

“…Beyond their role as possible sources of r-process nucleosynthesis and engines for powering luminous supernovae, millisecond magnetars are contenders for the central engines powering gammaray bursts (Usov 1992;Wheeler et al 2000;Thompson et al 2004;Metzger et al 2011a). If GRBs are indeed powered by the rotational energy of a magnetar, then the nucleosynthesis products of their winds will be directly entrained in the relativistic jet which escapes from the star and powers the prompt gamma-ray emission.…”

Section: Introductionmentioning

confidence: 99%

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Vlasov

Metzger

Lippuner

et al. 2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We explore heavy element nucleosynthesis in neutrino-driven winds from rapidly-rotating, strongly magnetized proto-neutron stars ("millisecond proto-magnetars") for which the magnetic dipole is aligned with the rotation axis, and the field is assumed to be a static force-free configuration. We process the proto-magnetar wind trajectories calculated by Vlasov et al. (2014) through the r-process nuclear reaction network SkyNet using contemporary models for the evolution of the wind electron fraction during the proto-neutron star cooling phase. Although we do not find a successful second or third peak r-process for any rotation period P, we show that proto-magnetars with P ∼ 1 − 5 ms produce heavy element abundance distributions that extend to higher nuclear mass number than from otherwise equivalent spherical winds (with the mass fractions of some elements enhanced by factors of ∼ > 100 − 1000). The heaviest elements are synthesized by outflows emerging along flux tubes which graze the closed zone and pass near the equatorial plane outside the light cylinder. Due to dependence of the nucleosynthesis pattern on the magnetic field strength and rotation rate of the proto-neutron star, natural variations in these quantities between core collapse events could contribute to the observed diversity of the abundances of weak r-process nuclei in metal-poor stars. Further diversity, including possibly even a successful third-peak r-process, could be achieved for misaligned rotators with non-zero magnetic inclination with respect to the rotation axis. If proto-magnetars are central engines for GRBs, their relativistic jets should contain a high mass fraction of heavy nuclei of characteristic mass numberĀ ≈ 100, providing a possible source for ultra-high energy cosmic rays comprised of heavy nuclei with an energy spectrum that extends beyond the nominal GZK cut-off for protons or iron nuclei.

show abstract

“…The idea of a loss of rotational energy during the birth process of a neutron star was already considered by Usov (1992) for the case of millisecond pulsars. On the other hand, Spruit (2008) has suggested that a differential rotation in the final stages of the core collapse process can produce magnetic fields typical of magnetars.…”

Section: Introductionmentioning

confidence: 99%

Birth accelerations of neutron stars

Heras¹

2012

Proc. IAU

View full text Add to dashboard Cite

Abstract. We suggest that neutron stars experienced at birth three related physical changes, which may originate in magneto-rotational instabilities: (i) an increase in period from the initial value P 0 to the current value Ps , implying a change of rotational energy ΔErot ; (ii) an exponential decay of its magnetic field from the initial value B0 to the current surface value Bs , implying a change of radiative energy ΔE rad ; and (iii) an increase of space velocity from the initial value v0 to the current value v, implying a change of kinetic energy ΔE kin . These changes are assumed to be connected by ΔE rad + ΔE kin = ΔErot . This means that the radiation loss and increase of kinetic energy are both at the expense of a rotational energy loss. It is shown that this energy conversion occurs during times of order of 10 −4 s if the neutron stars are born with magnetic fields in the range of 10 15 −10 16 G and initial periods in range 1−20 ms. It is shown that the birth accelerations of neutron stars are of the order of 10 8 g.

show abstract

Millisecond pulsars with extremely strong magnetic fields as a cosmological source of γ-ray bursts

Cited by 958 publications

References 26 publications

Frequency-dependent effects of gravitational lensing within plasma

Frequency-dependent effects of gravitational lensing within plasma

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Birth accelerations of neutron stars

Contact Info

Product

Resources

About