中子星低质量X射线双星暂现源XTE J1701$-$462中强变X射线偏振的发现
高能天体物理现象
2023-06-21 v1 太阳与恒星天体物理
摘要
在首次爆发约16年后，暂现中子星低质量X射线双星XTE J1701462于2022年9月再次活跃，使得借助成像X射线偏振探测器（IXPE）的专项观测计划得以首次研究其X射线偏振特性。对XTE J1701462的偏振研究有望增进我们对吸积弱磁化中子星的理解，特别是靠近致密天体的热内区的物理与几何结构。利用时间分辨光谱与偏振技术分析了两次触发观测的IXPE数据，沿其颜色-颜色图的Z迹追踪该源。在2022年9月29日的首次指向期间，测得2-8 keV平均偏振度为4.60.4%，这是迄今此类源中所发现的最高值。相反，十天后的第二次指向期间平均偏振度仅约0.6%。偏振信号似乎与边界层（BL）辐射及其来自内吸积盘的反射所关联的高能黑体分量严格相关，且在两次测量中高于3-4 keV时分别强达6.1%和1.2%（显著性>95%）。变偏振信号显然与XTE J1701462的光谱特征相关，当该源处于其Z迹的水平分支时最强，在正规分支时最弱。这些IXPE结果为Z源的物理解释与几何结构提供了新的重要观测约束。在此，我们讨论了这些源中存在强且可变偏振的可能原因。
引用
@article{arxiv.2306.10965,
title = {Discovery of strongly variable X-ray polarization in the neutron star low-mass X-ray binary transient XTE J1701$-$462},
author = {Massimo Cocchi and Andrea Gnarini and Sergio Fabiani and Francesco Ursini and Juri Poutanen and Fiamma Capitanio and Anna Bobrikova and Ruben Farinelli and Adamantia Paizis and Lara Sidoli and Alexandra Veledina and Stefano Bianchi and Alessandro Di Marco and Adam Ingram and Jari J. E. Kajava and Fabio La Monaca and Giorgio Matt and Christian Malacaria and Romana Mikušincová and John Rankin and Silvia Zane and Iván Agudo and Lucio A. Antonelli and Matteo Bachetti and Luca Baldini and Wayne H. Baumgartner and Ronaldo Bellazzini and Stephen D. Bongiorno and Raffaella Bonino and Alessandro Brez and Niccolò Bucciantini and Simone Castellano and Elisabetta Cavazzuti and Chien-Ting Chen and Stefano Ciprini and Enrico Costa and Alessandra De Rosa and Ettore Del Monta and Laura Di Gesu and Niccolò Di Lalla and Immacolata Donnarumma and Victor Doroshenko and Michal Dovčiak and Steven R. Ehlert and Teruaki Enoto and Yuri Evangelista and Riccardo Ferrazzoli and Javier A. Garcia and Shuichi Gunji and Kiyoshi Hayashida and Jeremy Heyl and Wataru Iwakiri and Svetlana G. Jorstad and Philip Kaaret and Vladimir Karas and Fabian Kislat and Takao Kitaguchi and Jeffery J. Kolodziejczak and Henric Krawczynski and Luca Latronico and Ioannis Liodakis and Simone Maldera and Alberto Manfreda and Frédéric Marin and Andrea Marinucci and Alan P. Marscher and Herman L. Marshall and Francesco Massaro and Ikuyuki Mitsuishi and Tsunefumi Mizuno and Fabio Muleri and Michela Negro and Chi-Yung Ng and Stephen L. O'Dell and Nicola Omodei and Chiara Oppedisano and Alessandro Papitto and George G. Pavlov and Abel L. Peirson and Matteo Perri and Melissa Pesce-Rollins and Pierre-Olivier Petrucci and Maura Pilia and Andrea Possenti and Simonetta Puccetti and Brian D. Ramsey and Ajay Ratheesh and Oliver J. Roberts and Roger W. Romani and Carmelo Sgrò and Patrick Slane and Paolo Soffitta and Gloria Spandre and Douglas A. Swartz and Toru Tamagawa and Fabrizio Tavecchio and Roberto Taverna and Yuzuru Tawara and Allyn F. Tennant and Nicholas E. Thomas and Francesco Tombesi and Alessio Trois and Sergey S. Tsygankov and Roberto Turolla and Jacco Vink and Martin C. Weisskopf and Kinwah Wu and Fei Xie},
journal= {arXiv preprint arXiv:2306.10965},
year = {2023}
}
备注
7 pages, 8 figures; published in A&A 674, L10 (2023)