Title: A high-density relativistic reflection origin for the soft and hard X-ray excess emission from Mrk 1044 Show Chinese title

Title: Mark 1044软硬X射线超额发射的高密度相对论反射起源

Abstract: We present the first results from a detailed spectral-timing analysis of a long ($\sim$130 ks) XMM-Newton observation and quasi-simultaneous NuSTAR and Swift observations of the highly-accreting narrow-line Seyfert 1 galaxy Mrk 1044. The broadband (0.3$-$50 keV) spectrum reveals the presence of a strong soft X-ray excess emission below $\sim$1.5 keV, iron K$_{\alpha}$ emission complex at $\sim$6$-$7 keV and a `Compton hump' at $\sim$15$-$30 keV. We find that the relativistic reflection from a high-density accretion disc with a broken power-law emissivity profile can simultaneously explain the soft X-ray excess, highly ionized broad iron line and the Compton hump. At low frequencies ($[2-6]\times10^{-5}$ Hz), the power-law continuum dominated 1.5$-$5 keV band lags behind the reflection dominated 0.3$-$1 keV band, which is explained with a combination of propagation fluctuation and Comptonization processes, while at higher frequencies ($[1-2]\times10^{-4}$ Hz), we detect a soft lag which is interpreted as a signature of X-ray reverberation from the accretion disc. The fractional root-mean-squared (rms) variability of the source decreases with energy and is well described by two variable components: a less variable relativistic disc reflection and a more variable direct coronal emission. Our combined spectral-timing analyses suggest that the observed broadband X-ray variability of Mrk~1044 is mainly driven by variations in the location or geometry of the optically thin, hot corona. Show Chinese abstract

Abstract: 我们展示了对Markarian 1044（这是一个高吸积窄线赛弗特1型星系）的长时间（$\sim$130 ks）XMM-Newton 观测以及准同时NuSTAR和Swift观测的详细光谱-时间分析的第一个结果。 宽波段（0.3$-$50 keV）谱线显示了存在一个强烈的软 X 射线过量辐射，其能量低于$\sim$1.5 keV，在铁的 K$_{\alpha}$辐射复合线附近（$\sim$6$-$7 keV），以及在$\sim$15$-$30 keV 处的“康普顿峰”。 我们发现，来自具有幂律截断发射率分布的高密度吸积盘的相对论反射能够同时解释软 X 射线过量辐射、高度电离的宽铁线和康普顿峰。 在低频（$[2-6]\times10^{-5}$Hz）时，幂律连续区主导的1.5$-$5 keV能段比反射主导的0.3$-$1 keV能段滞后，这可以用传播涨落和康普顿化过程的组合来解释；而在较高频率（$[1-2]\times10^{-4}$Hz）时，我们探测到一个软滞后，这被解释为吸积盘反射的X射线回波的标志。 源的分数均方根（rms）波动随能量减小，并且可以很好地用两个可变组分来描述：较不变化的相对论性盘反射和较变化的直接日冕发射。 我们的联合光谱-时间分析表明，Mrk~1044观测到的宽带X射线波动主要由光学薄热日冕的位置或几何形状的变化驱动。