论文标题
重新审视NGC 2992在历史悠久的状态下的周环X射线排放
Revisit the Circumnuclear X-ray Emission of NGC 2992 in a Historically Low State
论文作者
论文摘要
长期以来一直怀疑Seyfert Galaxy NGC 2992的内部区域是强烈的Agn-Host Galaxy相互作用的位置，但是在先前的高分辨率观察中，光子堆积阻碍了对软X射线过量的研究及其核附近的相互作用的研究。我们提出了X射线成像光谱分析（$ 1^{\ prime \ prime} $ - $ 3^{\ prime \ prime \ prime} $ 2992的区域，使用135 ks grate观察到的Chandra获得的零级观察的零级图像，该图像获得了奇特拉（Chandra），该观察结果捕获了历史悠久的低位量核的核心。在周环区域中检测到扩展的软X射线发射，观察到的光度$ l _ {\ rm x} \ sim 7 \ times 10^{39} {39} \ rm \ erg \ erg \ s^{ - 1} $。先前对软过量过量的令人困惑的检测的大多数可能与流出有关，这是由软X射线发射与图形八射电气泡之间的形态学对应关系所表明的。发现一条带有Centroid Energy $ \ sim4.97 $ keV的窄发射线。如果归因于红移高度离子化的铁发射（例如，fe XXV），则所需的流速度为$ \ sim0.23 \，c $。另一种解释是铁发射可以通过铁的核剥落产生。我们还发现沿银河磁盘的不对称扩展Fe K $α$排放可能源于冷气对$ \ sim 200 $ PC量表的反射。
The inner-most region of the Seyfert galaxy NGC 2992 has long been suspected to be the location of intense AGN-host galaxy interaction, but photon pile-up in previous high-resolution observations hampered the study of soft X-ray excess and the interaction near its nucleus. We present an X-ray imaging spectroscopic analysis of the circumnuclear ($1^{\prime\prime}$--$3^{\prime\prime}$) region of NGC 2992 using the zeroth-order image of a 135 ks grating observation obtained with Chandra, which captured the nucleus in a historically low flux state. Extended soft X-ray emission is detected in the circumnuclear region with observed luminosity $L_{\rm X} \sim 7 \times 10^{39}\rm\ erg\ s^{-1}$. The majority of previously puzzling detection of soft excess could be associated with the outflow, indicated by the morphological correspondences between soft X-ray emission and figure-eight-shaped radio bubbles. An anomalous narrow emission line with the centroid energy $\sim4.97$ keV is found. If attributed to redshifted highly ionized iron emission (e.g., Fe xxv), the required outflow velocity is $\sim0.23\,c$. An alternative explanation is that this line emission could be produced by the nuclear spallation of iron. We also find asymmetric extended Fe K$α$ emission along the galactic disk, which could originate from reflection by cold gas on $\sim 200$ pc scale.
