论文标题
清除：高离子化[NE V] $λ$ 3426排放线星系，$ 1.4 <z <2.3 $
CLEAR: High-Ionization [Ne V] $λ$3426 Emission-line Galaxies at $1.4 <z< 2.3$
论文作者
论文摘要
我们使用Hubble Space望远镜/宽场摄像头3 G102和G141 G141 GRISM观察值分析了25 [NE V] $λ$ 3426发射线星系，$ 1.4 <z <2.3 $。 [NE V]发射探针极高的光电离（97.11-126.21 eV），通常归因于活性银河核（AGN）的能量辐射，超新星的冲击，或者是恒星连续体的否则硬电离频谱。在这项工作中，我们将[NE V]与其他休息框UV/光学排放线（[O II] $λλ$ 3726,3729，[NE III] $λ$ 3869，H $ 3869，H $β$，[O III] $λλ$ 6716,6731），深（2--7毫秒）X射线观测（来自Chandra）和中红外成像（从Spitzer）研究这种发射的起源并对电离引擎的性质施加约束。大多数[NE V]检测的星系具有与AGN电离一致的特性。但是，对于我们的[NE V]选择样本，X射线亮度与局部（$ Z \ Lessim 0.1 $）X射线选择的Seyferts一致，但是[NE V] Luminosities与$ Z \ sim 1 $ X射线X射线选择的QSOS的亮度更加一致。多余的[NE V]排放需要减少硬X射线或$ \ sim $ 0.1 keV多余。我们讨论了明显的[Ne V]过量的可能起源，这可能与某些QSOS和SEYFERT中观察到的``软（X射线）过量''和/或成为狭窄线区域的复杂/各向异性几何形状的结果，并与来自温暖的，相对的风能散发出狭窄的线区域相关。我们还考虑了与JWST的电离时代（$ z \ gtrsim 6 $）中极端高级化体系的未来研究的影响。
We analyze a sample of 25 [Ne V] $λ$3426 emission-line galaxies at $1.4<z<2.3$ using Hubble Space Telescope/Wide Field Camera 3 G102 and G141 grism observations from the CANDELS Lyman-$α$ Emission at Reionization (CLEAR) survey. [Ne V] emission probes extremely energetic photoionization (97.11-126.21 eV), and is often attributed to energetic radiation from active galactic nuclei (AGN), shocks from supernova, or an otherwise very hard ionizing spectrum from the stellar continuum. In this work, we use [Ne V] in conjunction with other rest-frame UV/optical emission lines ([O II] $λλ$3726,3729, [Ne III] $λ$3869, H$β$, [O III] $λλ$4959,5007, H$α$+[N II] $λλ$6548,6583, [S II] $λλ$6716,6731), deep (2--7 Ms) X-ray observations (from Chandra), and mid-infrared imaging (from Spitzer) to study the origin of this emission and to place constraints on the nature of the ionizing engine. The majority of the [Ne V]-detected galaxies have properties consistent with ionization from AGN. However, for our [Ne V]-selected sample, the X-ray luminosities are consistent with local ($z\lesssim 0.1$) X-ray-selected Seyferts, but the [Ne V] luminosities are more consistent with those from $z\sim 1$ X-ray-selected QSOs. The excess [Ne V] emission requires either reduced hard X-rays, or a $\sim$0.1 keV excess. We discuss possible origins of the apparent [Ne V] excess, which could be related to the ``soft (X-ray) excess'' observed in some QSOs and Seyferts, and/or be a consequence of a complex/anisotropic geometry for the narrow line region, combined with absorption from a warm, relativistic wind ejected from the accretion disk. We also consider implications for future studies of extreme high-ionization systems in the epoch of reionization ($z \gtrsim 6$) with JWST.
