论文标题
宇宙中午的类星体的模糊部分
The Obscured Fraction of Quasars at Cosmic Noon
论文作者
论文摘要
X射线选定的活性银河核（AGN）的统计研究表明，遮盖的AGN的比例随着红移的增加而增加，结果表明，早期宇宙中遮盖物质的大部分发生在掩盖物质背后。我们利用宽大，深X射线和光学/IR成像数据集研究了在超级质量黑洞生长的峰值时期，高度积聚的X射线AGN的遮挡分数。通过将XMM-Servs XMM-Servs X-Ray点点源目录与PSF-CONVOLVED光度目录覆盖的XMM-Servs XMM-Servs XMM-Servs XMM-servs XMM-Servs XMM-servs XMM-Servs Sopt-Source目录构建的独特样品是构建的，该目录覆盖从$ u^*$到4.5 $μ\ mathrm {M Mathrm {M} $ bands。估计了X射线选定候选物的光度红移，氢柱密度和2-10 KEV AGN光度。使用306 2-10 keV在上述红移2处检测到的AGN，我们估计具有$ \ log n _ {\ rm h} \（\ rm h} \（\ rm cm^{ - 2}）> 22 $的AGN的比例，假设参数X射线亮度和吸收功能。结果表明，$ 76 _ { - 3}^{+4} \％$ $ $ $ $ $ $ $ $ $ $ $（$ \ log l_x \（\ rm erg \ s^{ - 1}）> 44.5 $）在redshift 2上方被遮盖。该分数表明，高红移的积聚的贡献要比当地宇宙中的贡献增加。我们讨论了根据AGN晦涩的场景增加的红移越来越多的晦涩的分数的含义，这些场景描述了当地宇宙中的晦涩难懂的特性。被遮盖的$ z> 2 $ agn都表现出广泛的SED和形态，这可能反映出与晦涩的宿主星系特性和物理过程相关的各种各样的。
Statistical studies of X-ray selected Active Galactic Nuclei (AGN) indicate that the fraction of obscured AGN increases with increasing redshift, and the results suggest that a significant part of the accretion growth occurs behind obscuring material in the early universe. We investigate the obscured fraction of highly accreting X-ray AGN at around the peak epoch of supermassive black hole growth utilizing the wide and deep X-ray and optical/IR imaging datasets. A unique sample of luminous X-ray selected AGNs above $z>2$ was constructed by matching the XMM-SERVS X-ray point-source catalog with a PSF-convolved photometric catalog covering from $u^*$ to 4.5$μ\mathrm{m}$ bands. Photometric redshift, hydrogen column density, and 2-10 keV AGN luminosity of the X-ray selected AGN candidates were estimated. Using the sample of 306 2-10 keV detected AGN at above redshift 2, we estimate the fraction of AGN with $\log N_{\rm H}\ (\rm cm^{-2})>22$, assuming parametric X-ray luminosity and absorption functions. The results suggest that $76_{-3}^{+4}\%$ of luminous quasars ($\log L_X\ (\rm erg\ s^{-1}) >44.5$) above redshift 2 are obscured. The fraction indicates an increased contribution of obscured accretion at high redshift than that in the local universe. We discuss the implications of the increasing obscured fraction with increasing redshift based on the AGN obscuration scenarios, which describe obscuration properties in the local universe. Both the obscured and unobscured $z>2$ AGN show a broad range of SEDs and morphology, which may reflect the broad variety of host galaxy properties and physical processes associated with the obscuration.
