KIC 9406652: A laboratory for tilted disks in cataclysmic variable stars. II. Modeling of the orbital light curves
KIC 9406652: A laboratory for tilted disks in cataclysmic variable stars. II. Modeling of the orbital light curves
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KIC 9406652：灾难变星倾斜盘实验室。
DOI：
10.1093/pasj/psab069
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发表时间：
2021
影响因子：
2.3
通讯作者：
Osaki Yoji
中科院分区：
文献类型：
--
作者：
Kimura Mariko;Osaki Yoji
KIC 9406652是最近发现的IW - and型矮新星之一，是研究突变变星倾斜盘的最佳目标。Kimura et al. （2020b， PASJ, 72, 94）在之前的一篇论文中分析了它的开普勒光曲线，发现它在变亮阶段的轨道光曲线主要受副星的反射效应支配，并随着倾斜盘的方向而变化；振幅在超轨道信号的最小值处最大，光最大值的相位随着超轨道相位的推进而提前。我们在那篇文章中认为，这是逆行进动的倾斜圆盘的直接证据，因为副恒星就像一个反射物体。为了证实这一解释，本文对轨道光曲线进行了数值模拟。我们通过一个简单的模型成功地再现了观测到的轨道光曲线的主要特征，在这个模型中，副恒星被倾斜的圆盘照射。我们还从光度学的考虑，限制了双星系统的倾角i和盘的倾角θ。最佳拟合参数集分别为0 ~ 45°和。这样估计的轨道倾角与在不确定度限制内从光谱考虑得到的结果是一致的。另一方面，仅使用超轨道信号的半振幅可能会低估盘的倾斜角。
KIC 9406652, one of the recently identified IW And-type dwarf novae, is the best target for studying the tilted disk in cataclysmic variable stars. In a previous paper by Kimura et al. (2020b, PASJ, 72, 94), we analyzed its Kepler light curves and found that its orbital light curves during the brightening stage were dominated by the reflection effect of the secondary star and varied with the orientation of the tilted disk; the amplitude was maximized at the minimum of the super-orbital signal and the phase of the light maximum shifted to an earlier one with the advance of the super-orbital phase. We argued in that work that this was direct evidence of the retrogradely precessing tilted disk as the secondary star acts like a reflecting object. In order to confirm this interpretation, we have performed numerical modeling of orbital light curves in this paper. We have succeeded in reproducing the main characteristics of the observed orbital light curves by a simple model in which the secondary star is irradiated by the tilted disk. We have also constrained the inclination angle,i, of the binary system and the tilt angle, θ, of the disk purely from photometric considerations. The best-fitting parameter set is found to bei∼ 45° and, respectively. The orbital inclination thus estimated is consistent with that obtained from the spectroscopic considerations within the uncertainty limit. On the other hand, the tilt angle of the disk could be underestimated by using only the semi-amplitude of super-orbital signals.