# IWARA2018 - 8th International Workshop on Astronomy and Relativistic Astrophysics

8-15 September 2018
America/Lima timezone

## Investigations of the Ohmic decay and the soft X-ray emission of high-braking index pulsar PSR J1640$-$4631

11 Sep 2018, 09:30
20m
Talk

### Speaker

Zhifu Gao (Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150, Science 1-Street, Urumqi, Xinjiang 830011, China)

### Description

In this work, we investigate the Ohmic decay of surface dipole magnetic field of high-braking index pulsar PSR J1640$-$4631, and interpret the observed soft X-ray flux $F_{x}^{\infty}[2-10\rm keV]$ from $Chandra +NuStar$ telescopes. We obtain the ohmic decay timescale $\tau_{\rm ohm}\sim 3.23\times10^{6}$ yr. Observations indicate that magnetic multipole fields could exist in a neutron star and the toroidal component of multipole fields at and near the pulsar cap is thought to be responsible for the star's unique pulse profile. A possible application of ohmic decay timescale to thermoplastic wave (TPW) heating due to toroidal fields dispassion is studied for interpreting the observed soft x-ray emission of PSR J1640$-$4631, and other heating mechanisms for the star's surface thermal emission are also investigated.

### Primary authors

Zhifu Gao (Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150, Science 1-Street, Urumqi, Xinjiang 830011, China) Na Wang (Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150, Science 1-Street, Urumqi, Xinjiang 830011, China) Jia Huanyu (School of Physical Science and Technology, Southwest Jiaotong University,Chengdu 610031, China) Li Xiangdong (Department of Astronomy and Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University, Jiangsu 210046, China)

### Co-author

Wang Hui (Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150, Science 1-Street, Urumqi, Xinjiang 830011, ChinaSchool of Physical Science and Technology, Southwest Jiaotong University,Chengdu 610031, China)