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Novel Clues to the Physics of Magnetars as Probed with Detailed Pulse-Timing Studies

Published online by Cambridge University Press:  27 February 2023

Kazuo Makishima*
Affiliation:
Kavli IPMU, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba, Japan, 277-8583 email: [email protected] Dept. of Physics, University of Tokyo, 7-3-1 Hong, Bunkyo-ku, Tokyo, Japan, 113-0033
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Abstract

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Broadband X-ray data of five magnetars show that their hard X-ray pulses suffer periodic phase modulations, at a period ∼ 104 times their pulse period. The phenomenon is interpreted as a result of free precession of neutron stars that are prolately deformed to an asphericity of ∼ 10−4, by the magnetic stress of toroidal fields reaching ∼ 1016 G. The behavior is absent in their soft X-ray pulses, probably due to a higher emission symmetry. The ultra-high toroidal fields, considered common to magnetars, may persist longer than their dipole fields.

Type
Contributed Paper
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of International Astronomical Union

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