利用TESS探测耀变体PKS 0422+004的天量级准周期振荡

Detection of Quasiperiodic Oscillation on the Order of Days in Blazar PKS 0422+004 with TESS

凌日系外行星巡天卫星(Transiting Exoplanet Survey Satellite,TESS)观测到的耀变体PKS 0422+004(α=042446.8421990080,δ=+003606.329375028)的光学波段光变曲线在第32扇区存在约7.4天的准周期振荡(Quasiperiodic Oscillation,QPO)。使用LSP(Lomb-Scargle Periodogram)方法寻找显著性周期,并用加权小波Z变换(Weight Wavelet Z-transform,WWZ)方法进行时频域分析进一步验证。最后,基于施瓦西黑洞(a=0)和极端克尔黑洞(a=0.9982)两种模型,估算了这个耀变体中心黑洞的质量。以7.4天为主周期,得到黑洞质量分别为1.11×10^(9)M_(⊙)(施瓦西黑洞)和7.07×10^(9)M_(⊙)(极端克尔黑洞)。

We find that the optical band light curve of the blazar PKS 0422+004 observed by the Transiting Exoplanet Survey Satellite(TESS)has a quasiperiodic oscillation(QPO)of about 7.4 days in sector 32.We use the Lomb-Scargle Periodogram(LSP)method to search for significant periods,and further validate them using the Weighted Wavelet Z-transform(WWZ)method for time-frequency domain analysis.Finally,based on Schwarzschild black hole(a=0)and extreme Kerr black hole(a=0.9982)models,we estimate the mass of the central black hole of this blazar.We obtain black hole masses of 1.11×10^(9)M_(⊙)(Schwarzschild black hole)and 7.07×10^(9)M_(⊙)(extreme Kerr black hole)with a main period of 7.4 days.