Spot-like Structures of Neutron Star Surface Magnetic Fields

Abstract

There is growing evidence, based on both X-ray and radio observations of isolated neutron stars, that besides the large--scale (dipolar) magnetic field, which determines the pulsar spin--down behaviour, small--scale poloidal field components are present, which have surface strengths one to two orders of magnitude larger than the dipolar component. We argue in this paper that the Hall--effect can be an efficient process in producing such small--scale field structures just above the neutron star surface. It is shown that due to a Hall--drift induced instability, poloidal magnetic field structures can be generated from strong subsurface toroidal fields, which are the result of either a dynamo or a thermoelectric instability acting at early times of a neutron star's life. The geometrical structure of these small--scale surface anomalies of the magnetic field resembles that of some types of ``star--spots''. The magnetic field strength and the length--scales are comparable with values that can be derived from various observations.

4 pages, 2 figures, accepted by Astronomy & Astrophysics Letters; language improved, 2nd para of Sect. 3 changed

References in corpus (14)

• Discovery of absorption features in the X-ray spectrum of an isolated neutron star
• Topology and Polarisation of Subbeams Associated With Pulsar 0943+10's ``Drifting''-Subpulse Emission: I. Analysis of Arecibo 430- and 111-MHz Observations
• Drifting subpulses and inner acceleration regions in radio pulsars
• Pulsar Magnetospheric Emission Mapping: Images and Implications of Polar-Cap Weather
• Spark Model for Pulsar Radiation Modulation Patterns
• A broad absorption feature in the X-ray spectrum of the isolated neutron star RBS1223 (1RXS J130848.6+212708)
• The influence of Hall drift on the magnetic fields of neutron stars
• Chandra X-Ray Observatory observations of the globular cluster M28 and its millisecond pulsar B1821-24
• 1E 1207.4-5209: The puzzling pulsar at the center of the PKS 1209-51/52 supernova remnant
• Vacuum gaps in pulsars and PSR J2144-3933
• Rapid dissipation of magnetic fields due to Hall current
• Non--linear magnetic field decay in neutron stars -- Theory and observations
• Modelling of surface magnetic field in neutron stars: application to radio pulsars
• On the formation of inner vacuum gaps in radio pulsars

Cited by in corpus (30)

• The Cooling of Compact Stars
• Magnetic Field Evolution in Neutron Star Crusts due to the Hall Effect and Ohmic Decay
• The bottom magnetic field and magnetosphere evolution of neutron star in low mass X-ray binary
• Upper Limit on the QCD Axion Mass from Isolated Neutron Star Cooling
• Evidence for Heating of Neutron Stars by Magnetic Field Decay
• Unveiling the thermal and magnetic map of neutron star surfaces though their X-ray emission: method and lightcurves analysis
• On the origins of part-time radio pulsars
• Investigation of nulling and subpulse drifting properties of PSR J1727$-$2739
• Unraveling the drift behaviour of the remarkable pulsar PSR B0826-34
• Young magnetars with fracturing crusts as fast radio burst repeaters
• XMM-Newton Observations of Radio Pulsars B0834+06 and B0826-34 and Implications for Pulsar Inner Accelerator
• Magnetic field decay with Hall drift in neutron star crusts
• On the Apparent Nulls and Extreme Variability of PSR J1107-5907
• Hall drift of axisymmetric magnetic fields in solid neutron-star matter
• The Occurrence of the Hall--Instability in Crusts of Isolated Neutron Stars
• Gravitational-wave spin-down and stalling lower limits on the electrical resistivity of the accreted mountain in a millisecond pulsar
• Formation of a Partially-Screened Inner Acceleration Region in Radio Pulsars: Drifting Subpulses and Thermal X-Ray Emission from Polar Cap Surface
• On the pulse-width statistics in radio pulsars. III. Importance of the conal profile components
• Long-term Radio Observations of the Intermittent Pulsar B1931+24
• Radio pulsar activity and the crustal Hall drift
• On the Pulse Intensity Modulation of PSR B0823+26
• The magnetic structure of neutron stars and their surface-to-core temperature relation
• Twist-induced Magnetosphere Reconfiguration for Intermittent Pulsars
• Joule heating in high magnetic field pulsars
• Explaining the subpulse drift velocity of pulsar magnetosphere within the space-charge limited flow model
• Monopolar and quadrupolar gravitational radiation from magnetically deformed neutron stars in modified gravity
• Turning Points in the Evolution of Isolated Neutron Stars' Magnetic Fields
• Phase transitions and latent heat in magnetized matter
• Thermal emission from Isolated Neutron Stars and their surface magnetic field: going quadrupolar?
• Individual pulse emission from the diffuse drifter PSR J1401$-$6357 using the ultrawideband receiver on the Parkes radio telescope