Interaction of misaligned magnetospheres in the coalescence of binary neutron stars

Ponce, Marcelo; Palenzuela, Carlos; Lehner, Luis; Liebling, Steven L.

doi:10.1103/physrevd.90.044007

Cited by 49 publications

(85 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition this scenario has also been invoked to drive powerful fireballs (Metzger & Zivancev 2016) and Fast Radio Bursts (FRBs) (Wang et al 2016). Since the highly dynamical electromagnetic field configurations present in the inspiraling binary are too involved to be studied using purely analytical approaches a few numerical studies have been performed in order to study force-free magnetospheric interactions, either in binary black hole mergers (Alic et al 2012;Palenzuela et al 2010), in neutron star binaries (Palenzuela et al 2013b,a;Ponce et al 2014), in mixed binaries (Paschalidis et al 2013) and in collapsing neutron stars (Lehner et al 2012;Palenzuela 2013) (see also Most et al (2018a);Nathanail et al (2017) for electrovacuum simulations). While these studies have been performed self-consistently in full general relativity they have not studied the main source of energy dissipation in current sheets, which are important sources of broad-band electromagnetic emission.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic Precursors to Gravitational-wave Events: Numerical Simulations of Flaring in Pre-merger Binary Neutron Star Magnetospheres

Most

Philippov

2020

ApJL

View full text Add to dashboard Cite

The detection of gravitational waves from neutron star merger events has opened up a new field of multi-messenger astronomy linking gravitional waves events to short-gamma ray bursts and kilonova afterglows. A further -yet to be discovered -electromagnetic counterpart is precursor emission produced by the non-trivial interaction of the magnetospheres of the two neutron stars prior to merger. By performing special-relativistic force-free simulations of orbiting neutron stars we discuss the effect of different magnetic field orientations and show how the emission can be significantly enhanced by differential motion present in the binary, either due to stellar spins or misaligned stellar magnetospheres. We find that the build-up of twist in the magnetic flux tube connecting the two stars can lead to the repeated emission of powerful flares for a variety of orbital configurations. We also discuss potential coherent radio emission mechanisms in the flaring process.

show abstract

Section: Introductionmentioning

confidence: 99%

Electromagnetic Precursors to Gravitational-wave Events: Numerical Simulations of Flaring in Pre-merger Binary Neutron Star Magnetospheres

Most

Philippov

2020

ApJL

View full text Add to dashboard Cite

show abstract

“…Simulations of compact NS binaries in full general relativity (GR), paying attention to precursor EM signals, has been carried out (see, e.g., [18] for a review). Latetime inspiral phases of NSNS were considered in [19][20][21] using general relativistic force-free (GRFF) simulations, broadly matching ideal magnetohydrodynamics (MHD) stellar interiors with an exterior force-free magnetosphere. Also, BHNS binary systems at fixed orbital separation -with and without BH spin-were studied in [22], relying on a similar GRFF numerical approach.…”

Section: Introductionmentioning

confidence: 99%

Magnetosphere of an orbiting neutron star

Carrasco

Shibata

2020

Phys. Rev. D

View full text Add to dashboard Cite

We conduct force-free simulations of a single neutron star undergoing orbital motion in flat spacetime, mimicking the trajectory of the star about the center of mass on a compact binary system. Our attention is focused on the kinetic energy being extracted from the orbit by the acceleration of the magnetic dipole moment of the neutron star, and particularly, on how this energy gets distributed within its surrounding magnetosphere. A detailed study of the resulting magnetospheric configurations in our setting is presented, incorporating as well the effects due to neutron star spin and the misalignment of the magnetic and orbital axes. We find many features resembling those of pulsar magnetospheres for the orbiting neutron star -even in the absence of spin-, being of particular interest the development of a spiral current sheet that extends beyond the light cylinder. Then, we use recent advances in pulsar theory to estimate electromagnetic emissions produced at the reconnection regions of such current sheets.

show abstract

“…[37] for a recent review of the field), but resolving the growth of magnetic instabilities at an acceptable computational cost remains an open problem [38]. Simulations using force-free or resistive magnetohydrodynamics, needed to properly simulate magnetically dominated regions, have also been performed [39][40][41][42]. So far they have, however, mostly studied the pre-merger evolution of the system.…”

Section: Introductionmentioning

confidence: 99%

Post-merger evolution of a neutron star-black hole binary with neutrino transport

et al. 2015

View full text Add to dashboard Cite

We present a first simulation of the post-merger evolution of a black hole-neutron star binary in full general relativity using an energy-integrated general relativistic truncated moment formalism for neutrino transport. We describe our implementation of the moment formalism and important tests of our code, before studying the formation phase of an accretion disk after a black hole-neutron star merger. We use as initial data an existing general relativistic simulation of the merger of a neutron star of mass 1.4M with a black hole of mass 7M and dimensionless spin χBH = 0.8. Comparing with a simpler leakage scheme for the treatment of the neutrinos, we find noticeable differences in the neutron to proton ratio in and around the disk, and in the neutrino luminosity. We find that the electron neutrino luminosity is much lower in the transport simulations, and that both the disk and the disk outflows are less neutron-rich. The spatial distribution of the neutrinos is significantly affected by relativistic effects, due to large velocities and curvature in the regions of strongest emission. Over the short timescale evolved, we do not observe purely neutrino-driven outflows. However, a small amount of material (3 × 10 −4 M ) is ejected in the polar region during the circularization of the disk. Most of that material is ejected early in the formation of the disk, and is fairly neutron rich (electron fraction Ye ∼ 0.15 − 0.25). Through r-process nucleosynthesis, that material should produce high-opacity lanthanides in the polar region, and could thus affect the lightcurve of radioactively powered electromagnetic transients. We also show that by the end of the simulation, while the bulk of the disk remains neutron-rich (Ye ∼ 0.15 − 0.2 and decreasing), its outer layers have a higher electron fraction: 10% of the remaining mass has Ye > 0.3. As that material would be the first to be unbound by disk outflows on longer timescales, and as composition evolution is slower at later times, the changes in Ye experienced during the formation phase of the disk could have an impact on nucleosynthesis outputs from neutrino-driven and viscously-driven outflows. Finally, we find that the effective viscosity due to momentum transport by neutrinos is unlikely to have a strong effect on the growth of the magnetorotational instability in the post-merger accretion disk.

show abstract

Interaction of misaligned magnetospheres in the coalescence of binary neutron stars

Cited by 49 publications

References 52 publications

Electromagnetic Precursors to Gravitational-wave Events: Numerical Simulations of Flaring in Pre-merger Binary Neutron Star Magnetospheres

Electromagnetic Precursors to Gravitational-wave Events: Numerical Simulations of Flaring in Pre-merger Binary Neutron Star Magnetospheres

Magnetosphere of an orbiting neutron star

Post-merger evolution of a neutron star-black hole binary with neutrino transport

Contact Info

Product

Resources

About