论文标题
NGC 3227的一系列XMM-Newton + Nustar观测的X射线变异性分析
X-ray variability analysis of a large series of XMM-Newton + NuSTAR observations of NGC 3227
论文作者
论文摘要
We present a series of X-ray variability results from a long XMM-Newton + NuSTAR campaign on the bright, variable AGN NGC 3227. We present an analysis of the lightcurves, showing that the source displays typically softer-when-brighter behaviour, although also undergoes significant spectral hardening during one observation which we interpret as due to an occultation event by a cloud of absorbing gas.我们从光谱分解数据并表明可变性的大部分是连续驱动的，并且通过RMS变异性分析，软带中的变异性分析很大。我们表明，来源在很大程度上符合线性RMS升华的行为，并计算X射线功率谱，检测到功率谱中弯曲的中等证据，与现有的缩放关系一致。此外，我们使用XMM-Newton和 - 通过最大的样式方法来计算X射线傅立叶时间滞后 - nustar数据，揭示了强烈的低频硬滞后滞后和在较高频率下具有软滞后的证据，我们以混响模型进行讨论。
We present a series of X-ray variability results from a long XMM-Newton + NuSTAR campaign on the bright, variable AGN NGC 3227. We present an analysis of the lightcurves, showing that the source displays typically softer-when-brighter behaviour, although also undergoes significant spectral hardening during one observation which we interpret as due to an occultation event by a cloud of absorbing gas. We spectrally decompose the data and show that the bulk of the variability is continuum-driven and, through rms variability analysis, strongly enhanced in the soft band. We show that the source largely conforms to linear rms-flux behaviour and we compute X-ray power spectra, detecting moderate evidence for a bend in the power spectrum, consistent with existing scaling relations. Additionally, we compute X-ray Fourier time lags using both the XMM-Newton and - through maximum-likelihood methods - NuSTAR data, revealing a strong low-frequency hard lag and evidence for a soft lag at higher frequencies, which we discuss in terms of reverberation models.
