The spin-orbit alignment hypothesis in millisecond pulsars

Abstract

Millisecond pulsars (MSPs) are spun up during their accretion phase in a binary system. The exchange of angular momentum between the accretion disk and the star tends to align the spin and orbital angular momenta on a very short time scale compared to the accretion stage. In this work, we study a subset of $\gamma$-ray MSPs in binaries for which the orbital inclination angle $i$ has been accurately constrained thanks to the Shapiro delay measurements. Our goal is to constrain the observer viewing angle $\zeta$ and to check whether it agrees with the orbital inclination angle $i$, in other words if $\zeta \approx i$. We use a Bayesian inference technique to fit the MSP $\gamma$-ray light curves based on the third $\gamma$-ray pulsar catalogue (3PC). The emission model relies on the striped wind model deduced from force-free neutron star magnetosphere simulations. We found good agreement between the two angles $i$ and $\zeta$ for a significant fraction of our sample, about four fifth, confirming the spin-orbit alignment scenario during the accretion stage. However about one fifth of our sample deviates significantly from this alignment. The reasons are manifold: either the $\gamma$-ray fit is not reliable or some precession and external torque avoid an almost perfect alignment.

Accepted by A&A

References in corpus (42)

• 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: Millisecond Pulsar Parameter Estimation
• Bilby: A user-friendly Bayesian inference library for gravitational-wave astronomy
• Refined Mass and Geometric Measurements of the High-Mass PSR J0740+6620
• Formation of Double Neutron Star Systems
• The NANOGrav Nine-year Data Set: Mass and Geometric Measurements of Binary Millisecond Pulsars
• High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array
• The NANOGrav 11-year Data Set: Pulsar-timing Constraints On The Stochastic Gravitational-wave Background
• Very massive stars, pair-instability supernovae and intermediate-mass black holes with the SEVN code
• A NICER View of the Nearest and Brightest Millisecond Pulsar: PSR J0437$\unicode{x2013}$4715
• Modeling of Gamma-Ray Pulsar Light Curves with Force-Free Magnetic Field
• Modeling high-energy pulsar lightcurves from first principles
• The Radius of the High-mass Pulsar PSR J0740+6620 with 3.6 yr of NICER Data
• The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• Ab-Initio Pulsar Magnetosphere: Particle acceleration in Oblique Rotators and High-energy Emission Modeling
• Discovery of the Optical Counterparts to Four Energetic Fermi Millisecond Pulsars
• Gamma-Ray Emission in Dissipative Pulsar Magnetospheres: From Theory to Fermi Observations
• 3D Kinetic Pulsar Magnetosphere Models: Connecting to Gamma-Ray Observations
• Compact object mergers: exploring uncertainties from stellar and binary evolution with SEVN
• The pulsar force-free magnetosphere linked to its striped wind: time-dependent pseudo-spectral simulations
• Pulsed radiation from neutron star winds
• An unified polar cap/striped wind model for pulsed radio and gamma-ray emission in pulsars
• The pulsar synchrotron in 3D: curvature radiation
• Study of spider pulsar binary eclipses and discovery of an eclipse mechanism transition
• Multiband Optical Light Curves of Black-Widow Pulsars
• Optical Counterparts of Two Fermi Millisecond Pulsars: PSR J1301+0833 and PSR J1628-3205
• Neutron star mass estimates from gamma-ray eclipses in spider millisecond pulsar binaries
• Shapiro delay in the PSR J1640+2224 binary system
• A black widow population dissection through HiPERCAM multi-band light curve modelling
• On the non-detection of gamma-rays from energetic millisecond pulsars -- dependence on viewing geometry
• Bayesian inference for pulsar timing models
• A Dense Companion to the Short-Period Millisecond Pulsar Binary PSR J0636+5128
• Searches for Shapiro delay in seven binary pulsars using the MeerKAT telescope
• Shapiro delay in PSR~J1811$-$2405
• Magnetic angle evolution in accreting neutron stars
• The eccentric millisecond pulsar, PSR J0955$-$6150 I: Pulse profile analysis, mass measurements and constraints on binary evolution
• Modeling gamma-ray light curves with more realistic pulsar magnetospheres
• Irradiated but not eclipsed, the case of PSR J0610-2100
• Synthetic pulsar lightcurves from global kinetic simulations and comparison with the Fermi-LAT catalog
• Magnetic Inclination Evolution of Accreting Neutron Stars in Intermediate/Low-Mass X-ray Binaries
• Born to be recycled: a comprehensive population synthesis of the Galactic millisecond pulsars
• A census of galactic spider binary millisecond pulsars with the Nançay Radio Telescope

Cited by in corpus (1)

• Multi-wavelength emission modelling of PSR~J0437$-$4715