2024/04/04 by U. Geppert, Geppert, U.
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High-pressure geophysics and materials #Pulsars and Gravitational Waves Research #Solar and Stellar Astrophysics (astro-ph.SR) #Superconducting Materials and Applications
paper · pdf · doi:10.48550/arxiv.2404.03458
openalex publication_date 2024/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Millisecond pulsars (MSPs) are believed to be very old neutron stars (NSs) whose age may exceed significantly 108 yrs. Although cooling scenarios of isolated NSs predict for that age a surface temperature Ts∼ 104 K, observations of the nearest MSP J0437-4715 indicate Ts well above that value. Besides the heating of the polar cap surface by backflowing charged particles, Joule heating in the crust can contribute to the overall heat budget of MSPs. Since the dipolar field component, derived from P and P measurements, is much too weak for remarkable heating, smaller-scale structures should be analysed whether they can supply the demanded heat. For this purpose we study the small scale field structure of radio pulsars. Magnetic field components, significantly stronger than the dipolar one, may exist especially at the surface of MSPs. We assign upper limits to the strength of single field components up to a multipolarity of l=10 and the corresponding deviations from axial symmetry m ≤ l. Arguments are provided that the decay of the small-scale components with l=3 or l=4 of the crustal magnetic field may cause the relatively high surface temperature of isolated MSPs.