Investigating the origin of optical and X-ray pulsations of the transitional millisecond pulsar PSR J1023+0038
Investigating the origin of optical and X-ray pulsations of the transitional millisecond pulsar PSR J1023+0038
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研究过渡毫秒脉冲星 PSR J1023 0038 的光学和 X 射线脉动的起源
DOI：
10.1051/0004-6361/202244637
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
M. Turchetta
中科院分区：
文献类型：
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作者：
G. Illiano;A. Papitto;F. Ambrosino;A. Zanon;F. C. Zelati;L. Stella;L. Zampieri;A. Burtovoi;S. Campana;P. Casella;M. Cecconi;D. Martino;M. Fiori;A. Ghedina;M. Gonzales;M. H. Diaz;G. Israel;F. Leone;G. Naletto;H. Ventura;C. Riverol;L. Riverol;D. Torres;M. Turchetta
语境。 PSR J1023 + 0038 是第一颗被观测为光学和紫外脉冲星的毫秒脉冲星。迄今为止，它是唯一一颗光学跃迁毫秒脉冲星。旋转和吸积驱动的发射机制很难单独解释观察到的光学脉动特征。提出了结合这些标准发射过程的协同模型来解释 X 射线/紫外线/光学脉动的起源。目标。我们研究光学和 X 射线波段脉冲之间的相位滞后，以深入了解导致该相位滞后的物理机制。方法。我们对使用 XMM-Newton 和 NICER 卫星获取的 X 射线波段以及使用快速光度计 SiFAP2（安装在 3.6 m 国家伽利略望远镜）和 Aqueye +（安装在 1.8 m 哥白尼望远镜）获取的光学波段进行了同步或准同步观测的详细定时分析。我们通过使用两个谐波分量对折叠脉冲轮廓进行建模，估计了光学脉动相对于 X 射线的时滞。结果。在使用仪器（NICER 和 Aqueye +）获得的观测结果中，光脉冲滞后于 X 射线脉冲约 150 µs，其绝对定时不确定性远小于测量的滞后。我们还表明，光学和 X 射线脉动之间的相位滞后位于有限的值范围内，δφ ε (0 − 0 . 15)，该值在大约五年的时间尺度内保持不变。这表明两种脉动源自同一区域，并且支持共同发射机制的假设。我们的结果在冲击驱动的迷你脉冲星云场景中得到解释。这种情况表明，光学和X射线脉冲是由同步加速器发射产生的，该激波是在距脉冲星几个光柱半径（约100公里）的范围内形成的，脉冲星的条纹风在此遇到吸积盘流入。
Context. PSR J1023 + 0038 is the first millisecond pulsar that was ever observed as an optical and UV pulsar. So far, it is the only optical transitional millisecond pulsar. The rotation- and accretion-powered emission mechanisms hardly individually explain the observed characteristics of optical pulsations. A synergistic model, combining these standard emission processes, was proposed to explain the origin of the X-ray / UV / optical pulsations. Aims. We study the phase lag between the pulses in the optical and X-ray bands to gain insight into the physical mechanisms that cause it. Methods. We performed a detailed timing analysis of simultaneous or quasi-simultaneous observations in the X-ray band, acquired with the XMM-Newton and NICER satellites, and in the optical band, with the fast photometers SiFAP2 (mounted at the 3.6 m Telescopio Nazionale Galileo) and Aqueye + (mounted at the 1.8 m Copernicus Telescope). We estimated the time lag of the optical pulsation with respect to that in the X-rays by modeling the folded pulse profiles with two harmonic components. Results. Optical pulses lag the X-ray pulses by ∼ 150 µ s in observations acquired with instruments ( NICER and Aqueye + ) whose absolute timing uncertainty is much smaller than the measured lag. We also show that the phase lag between optical and X-ray pulsations lies in a limited range of values, δφ ∈ (0 − 0 . 15), which is maintained over timescales of about five years. This indicates that both pulsations originate from the same region, and it supports the hypothesis of a common emission mechanism. Our results are interpreted in the shock-driven mini pulsar nebula scenario. This scenario suggests that optical and X-ray pulses are produced by synchrotron emission from the shock that formed within a few light cylinder radii away ( ∼ 100km) from the pulsar, where its striped wind encounters the accretion disk inflow.