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| Investigations of the Ohmic Decay and the Soft X-Ray Emission of the High-braking-index Pulsar PSR J1640-4631 | |
Wang, Hui1,2; Gao, Zhifu3 ; Wang, Na3; Jia, Huanyu1; Li, Xiangdong4,5; Zhi, Qijun2,6
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| 2019-05-01 | |
| Source Publication | PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
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| ISSN | 0004-6280 |
| Volume | 131Issue:999Pages:054201 |
| Contribution Rank | 3 |
| Abstract | The young pulsar PSR J1640-4631 is the first pulsar reported with a high braking index, n = 3.15 +/- 0.03, and has attracted extensive attention. In this work, by inputting the equation of state, we obtain two typical and feasible ranges of the electrical conductivity in the crust of PSR J1640-4631. Then, by considering the effects of general relativity, we formulate the induction equation and use it to investigate the decay of crustal magnetic fields within two scenarios: pure Ohmic decay, and the combination of Ohmic decay and Hall drift. In the former scenario, we calculate the current magnetic field decay rates as dB(p)/dt similar to (0.78-1.00) x 10(7) G yr(-1) and dB(t)/dt similar to (0.82-1.05) x 10(8) G yr(-1) for the poloidal and toroidal parts, respectively, and estimate the current magnetic energy decay rate as L-B similar to (0.95-1.22) x 10(32) erg s(-1). In the latter scenario, the combination of Ohmic decay and Hall drift accelerates the decay of magnetic fields, and we calculate the current magnetic field decay rates as dB(p)/dt similar to (1.26-1.47) x 10(7) G yr(-1), and dB(t)/dt similar to (1.32-1.54) x 10(8) G yr(-1) for the poloidal and toroidal parts, respectively, and estimate the current magnetic energy decay rate as L-B similar to (1.86-2.18) x 10(32) erg s(-1). It is found that the recalculated value of the braking index n of the star is lower than its observed value, which implies that other factors influence the spin-down evolution. The current magnetic energy decay rates calculated in both scenarios are far less than the isotropic soft X-ray luminosity obtained from Chandra+NuStar telescopes. The observed soft X-ray flux in the (2-10) keV band is F-X similar to 1.8(4) x 10(-13) erg cm(-2) s(-1), which corresponds to a high surface temperature, T similar to 1.54(6) x 10(6) K. The observed X-ray flux of the star could be caused by the decay of a multipolar magnetic field near the pole, which is strong enough to activate the slot-gap mechanism. The high surface temperature of the star is attributed either to magnetic spot formation or thermoplastic wave heating due to the decay of the toroidal field near the pole. Our results could be useful in interpreting the high soft X-ray flux from high magnetic field pulsars. |
| Keyword | Individual PSR J1640-4631 Ohmic decay Thermoplastic wave heating |
| DOI | 10.1088/1538-3873/ab0440 |
| Indexed By | SCI |
| Language | 英语 |
| WOS Keyword | MAGNETIC-FIELD EVOLUTION ; NEUTRON-STAR CRUSTS ; SURFACE-TEMPERATURE ; DENSE MATTER ; GAMMA-RAY ; SPIN-DOWN ; CORE ; INSTABILITY ; DIVERSITY ; EQUATION |
| Funding Project | National Basic Research Program of China grants 973 Programs[2015CB857100] ; Chinese National Science Foundation[11175417] ; Chinese National Science Foundation[11173042] ; Chinese National Science Foundation[11547311] ; Chinese National Science Foundation[11847307] ; Chinese National Science Foundation[11333004] ; Chinese National Science Foundation[11773015] ; Chinese National Science Foundation[11573016] ; Chinese National Science Foundation[11565010] ; Chinese National Science Foundation[U18311120] ; Chinese National Science Foundation[U1731218] ; Chinese National Science Foundation[U1838201] ; Science and Technology Fund of Guizhou Province[(2015)5015] ; Science and Technology Fund of Guizhou Province[(2016)4008] ; Guizhou Provincial Joint Fount[(2017)7349] ; Doctor Starting Up Foundation of Guizhou Normal University[0516134] ; National Key Research and Development Program of China[2016YFA0400803] |
| WOS Research Area | Astronomy & Astrophysics |
| WOS Subject | Astronomy & Astrophysics |
| WOS ID | WOS:000461954200001 |
| Publisher | IOP PUBLISHING LTD |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/2537 |
| Collection | 射电天文研究室_脉冲星研究团组 110米口径全可动射电望远镜（QTT）_110米大口径全可动射电望远镜关键技术研究（973项目）_课题1：大样本射电天体的观测和前沿问题研究 110米口径全可动射电望远镜（QTT）_110米大口径全可动射电望远镜关键技术研究（973项目）_课题4：反射面高精度快速测量与主动面实时闭环修正 |
| Corresponding Author | Gao, Zhifu |
| Affiliation | 1.Southwest Jiaotong Univ, Sch Phys Sci & Technol, Chengdu 610031, Sichuan, Peoples R China 2.Guizhou Normal Univ, Guizhou Prov Key Lab Radio Astron & Data Proc, Guiyang 550001, Guizhou, Peoples R China 3.Chinese Acad Sci, Xinjiang Astron Observ, 150,Sci 1 St, Urumqi 830011, Xinjiang, Peoples R China 4.Nanjing Univ, Dept Astron, Nanjing 210046, Jiangsu, Peoples R China 5.Nanjing Univ, Key Lab Modern Astron & Astrophys, Nanjing 210046, Jiangsu, Peoples R China 6.Guizhou Normal Univ, Sch Phys & Elect Sci, Guiyang 550001, Guizhou, Peoples R China |
| Corresponding Author Affilication | Xinjiang Astronomical Observatory, Chinese Academy of Sciences |
| Recommended Citation GB/T 7714 | Wang, Hui,Gao, Zhifu,Wang, Na,et al. Investigations of the Ohmic Decay and the Soft X-Ray Emission of the High-braking-index Pulsar PSR J1640-4631[J]. PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC,2019,131(999):054201. |
| APA | Wang, Hui,Gao, Zhifu,Wang, Na,Jia, Huanyu,Li, Xiangdong,&Zhi, Qijun.(2019).Investigations of the Ohmic Decay and the Soft X-Ray Emission of the High-braking-index Pulsar PSR J1640-4631.PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC,131(999),054201. |
| MLA | Wang, Hui,et al."Investigations of the Ohmic Decay and the Soft X-Ray Emission of the High-braking-index Pulsar PSR J1640-4631".PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC 131.999(2019):054201. |
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| Wang-2019-Investigat（1335KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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