论文标题
NGC 2992.II中的活泼积聚磁盘。 2019/2021 X射线监控活动
The lively accretion disk in NGC 2992. II. The 2019/2021 X-ray monitoring campaigns
论文作者
论文摘要
我们报告了附近的Seyfert 2 Galaxy NGC 2992的短期和长期X射线特性，该特性与Swift，XMM-Newton和Nustar广泛观察。在两个监视活动的背景下，在2019年至2021年之间，Swift将源头的目标定位了100倍以上。进行了时间平均和时间分辨分析，我们发现NGC 2992的短期任期光谱特性由高度可变的核连续体主导。源在2-10 Kev Energy Band中从0.6到12 $ \ times $ 10 $^{ - 11} $ erg cm $^{ - 2} $ s $^{ - 1} $在两年长的Swift监视中。最快的2-10 keV通量变化（以$ \ sim60 \％$为倍）发生在几个小时的时间表上。来源的总体发射光谱与像电源法的连续体（$γ= 1.69 \ pm0.01 $）相一致，该连续体被恒定的右圆柱密度n $ _ {h} =（7.8 \ pm0.1）\ times $ 10 $^{21}} $^{21} $ $ \ $ \ rm cm cm^{-2} $。反射的排放可能是由于平均柱密度n $ _ {\ rm h} =（9.6 \ pm2.7）\ times $ 10 $^{22} $ $ \ $ \ rm cm^{ - 2} $，因此ngc 2992似乎具有全球构成的compton-thin-thin collnucele培养基。这种情况得到了对分数变异性的独立分析以及XMM-Newton多年光谱的完全支持。
We report on the short and long term X-ray properties of the bright nearby Seyfert 2 galaxy NGC 2992, which was extensively observed with Swift, XMM-Newton and NuSTAR. Swift targeted the source more than 100 times between 2019 and 2021 in the context of two monitoring campaigns. Both time-averaged and time-resolved analyses are performed, and we find that the short-to-long term spectral properties of NGC 2992 are dominated by a highly variable nuclear continuum. The source varied in the 2-10 keV energy band from 0.6 to 12 $\times$ 10$^{-11}$ erg cm$^{-2}$ s$^{-1}$ during the two year long Swift monitoring. The fastest 2-10 keV flux change (by a factor of $\sim60\%$) occurred on a timescale of a few hours. The overall emission spectrum of the source is consistent with a power law-like continuum ($Γ=1.69\pm0.01$) absorbed by a constant line-of-sight column density N$_{H}=(7.8\pm0.1)\times$ 10$^{21}$ $\rm cm^{-2}$. The reflected emission is likely due to matter with an average column density N$_{\rm H}=(9.6\pm2.7)\times$ 10$^{22}$ $\rm cm^{-2}$, thus NGC 2992 appears to have a globally Compton-thin circumnuclear medium. This scenario is fully supported by an independent analysis of the fractional variability and by XMM-Newton multi-year spectra.
