论文标题
检测$γ$ - 射线光曲线0244-470和4C+38.41中可能的瞬态准周期振荡。
The detection of possible transient Quasi-Periodic Oscillations in the $γ$-ray light curve of PKS 0244-470 and 4C+38.41
论文作者
论文摘要
费米 - 拉特（Fermi-Lat）的持续监视能力使$γ$ - 射线光线曲线在Blazar的$γ$ ray光曲线中探索了新的观点，可以在广泛的时间范围内探测这些来源。我们报告了Blazars PKS 0244-470和4C +38.41的长期$γ$射线光曲线中瞬时QPO的存在。我们首先使用贝叶斯块算法鉴定了不同的通量状态，然后探索了每个通量阶段的段中可能的瞬态QPO，其中通量水平在相当规则的间隔内变化。将其与源的固有方差相结合，我们确定了PKS 0244-470的两个通量阶段：一个活动（AP-1）和一个静态相（QP-1）。对于4C+38.41，我们类似地确定了四个活动（AP-1，AP-2，AP-3，AP-4）和两个静态（QP-1，QP-2）阶段。 PKS的AP-1阶段0244-470显示$ \ sim $ 225天的QPO持续8个周期（$ \ sim $ 4.1 $σ$）。在4C+38.41中，AP-1和AP-2阶段分别显示出$ \ sim $ 110天和$ \ sim $ 60天的行为，持续使用5个周期。在AP-3中，我们确定了三个子重点，所有这些都显示出$ \ sim $周的比例可能会复发，而五个完整的周期可能会重复上升，而在QP-1中，我们可以识别2个子量（Q1和Q2）。 Q1阶段显示了$ \ sim $ 104天，六个完整的周期。 Q2阶段还显示了QPO，但只有$ \ sim $ 3.7周期。我们讨论了可能的来源，并认为当前驱动的扭结不稳定性和弯曲的喷气模型似乎是较短且更长的QPO的原因。
The continuous monitoring capability of Fermi-LAT has enabled the exploration of Quasi-Periodic Oscillations (QPOs) in the $γ$-ray light curve of blazar that has given a new perspective to probe these sources over a wide range of time scales. We report the presence of transient QPOs in the long-term $γ$-ray light curve of blazars PKS 0244-470 and 4C +38.41. We first identified different flux states using the Bayesian Block algorithm and then explored the possible transient QPOs in the segments of each flux phase where the flux level changes over fairly regular intervals. Combining this with the source's intrinsic variance, we identified two flux phases for PKS 0244-470: one activity (AP-1) and one quiescent phase (QP-1). For 4C+38.41, we similarly identified four activity (AP-1, AP-2, AP-3, AP-4) and two quiescent (QP-1, QP-2) phases. AP-1 phase of PKS 0244-470 shows QPO of $\sim$225 days persisting for 8 cycles ($\sim$ 4.1$σ$). In 4C+38.41, AP-1 and AP-2 phases show QPO-like behavior of $\sim$110 days and $\sim$ 60 days, respectively, persisting for 5 cycles. In AP-3, we identified three sub-phases, and all show a $\sim$ week scale possible recurrent rise with five complete cycles, while in QP-1, we could identify 2 sub-phases (Q1, and Q2). Q1 phase shows a period of $\sim$ 104 days with six complete cycles. Q2 phase also shows QPO but with only $\sim$3.7 cycles. We discuss the possible origin and argue that the current driven kink instability and curved jet model seem the most likely cause for shorter and longer QPOs.
