吸積毫秒脈衝星IGR J17379-3747於2020年爆發之自轉與軌道參數以及隨光強度變化的時間噪音;Spin and Orbital Parameters and Flux-Dependent Timing Noise of Accreting Millisecond X-ray Pulsar IGR J17379-3747 in Its 2020 Outburst

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/91942

Title:	吸積毫秒脈衝星IGR J17379-3747於2020年爆發之自轉與軌道參數以及隨光強度變化的時間噪音;Spin and Orbital Parameters and Flux-Dependent Timing Noise of Accreting Millisecond X-ray Pulsar IGR J17379-3747 in Its 2020 Outburst
Authors:	宋紫熙;Sung, Tzu-Hsi
Contributors:	天文研究所
Keywords:	X光毫秒脈衝星;時間噪音;時序分析;雙星;軌道參數校正;Accreting Millisecond X-ray Pulsar;Timing Noise;Timing Analysis;binary star;parameter correction
Date:	2022-12-29
Issue Date:	2024-09-19 14:43:15 (UTC+8)
Publisher:	國立中央大學
Abstract:	本篇論文的研究致力於分析吸積毫秒脈衝星──IGR J17379-3747的脈衝時序特性。它於2020年爆發時，NICER於9月與10月進行觀測。我們對IGR J17379-3747的自轉與軌道參數進行初步的校正，但即使是我們求得的最佳參數解，仍舊無法完好地描述脈衝相位演化，於是我們將相位演化與此次爆發期間的X光光變曲線做比較，發現造成相位偏差的原因可能來自於隨光強度變化的時間噪音。　　我們根據NICER的觀測時間間隔將觀測資料分為三個部分，除了第一部分以外，第二、第三部分的脈衝相位與X光強度都有強烈的線性相關性，只不過第二部分呈現負相關，而第三部分呈現正相關。我們採用Kulkarni & Romanova (2013) 所提供之隨光強度變化的時間噪音模型分別對此三部分進行擬合，即使各部分的趨勢不同，仍能顯著地改善分析結果。　　除此之外，為了估算IGR J17379-3747的磁場大小，我們比較了2018年與2020年兩次爆發期間得到的自轉頻率，並假設非爆發期間的吸積力矩可以被忽略，最終得到的磁場大小為約1.174(46)×10^8 G。 ;We report our study on the pulsar timing of the accreting millisecond X-ray pulsar (AMXP) IGR J17379-3747. The observations were made by NICER in September and October during its 2020 outburst. The spin and orbital parameters of this AMXP were first refined but even the optimal parameters cannot well describe the evolution of the pulse phase. In comparison to the flux variation of this outburst, such deviation is likely caused by the flux-dependent timing noise. According to the observation time intervals of NICER, we separated the data into three parts. Except for the first part, pulsation phases of the second and third parts have strong correlations with the corresponding count rates but the correlation for the part 2 is negative whereas the part 3 is positive. We applied the flux-dependent timing noise model proposed by Kulkarni & Romanova (2013) for the three parts separately and found that it can significantly improve the fittings although the tendencies of them are different. In comparison to the spin frequency detected in 2018 and 2020 outbursts, the magnetic field of the neutron star is estimated as ~1.174(46)×10^8 G under the assumption that accretion torque can be neglected during the quiescent state.
Appears in Collections:	[Graduate Institute of Astronomy] Electronic Thesis & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	10	View/Open

社群 sharing

Loading...