标题： 宽带高红移耀变体的观测 显示英文标题

标题： Broadband Observations of High Redshift Blazars

摘要： 我们对四个高红移耀变体S5 0014+81 ($z=3.37$)，CGRaBS J0225+1846 ($z=2.69$)，BZQ J1430+4205 ($z=4.72$)，和3FGL J1656.2$-$3303 ($z=2.40$)进行了多波长研究，使用了来自{\it Swift}，{\it NuSTAR}，和{\it 费米}-大型面积望远镜(LAT)的准同时数据，以及档案中的{\it XMM-Newton}观测数据。 除了3FGL J1656.2$-$3303之外，其他源都不为人知为$\gamma$-ray发射器，我们对$\sim$7.5年的LAT数据的分析首次检测到CGRaBS J0225+1846的统计显著的$\gamma$-ray辐射。 我们生成了所有物体的宽波段能谱分布（SED），以{\it NuSTAR}观测时刻为中心，并使用一个区域轻子发射模型对其进行再现。 所有物体中的光学$-$紫外辐射可以由吸积盘的辐射来解释，而X射线到$\gamma$-ray窗口的SED则被发现主要由宽线区光子的逆康普顿散射主导。 它们都拥有十亿太阳质量的黑洞。 将这些源的吸积盘亮度和喷流功率与大量耀变体进行比较，我们发现它们占据高吸积盘亮度-喷流功率区域。 我们还详细研究了这些源的X射线光谱特性，重点研究软X射线缺乏的原因，这是在高红移射电亮类星体中通常看到的一个特征。 我们总结说，这一特征可以基于喷流辐射的固有曲率来解释，而不是由于早期研究中预测的外部效应，如宿主星系和/或温暖吸收。 显示英文摘要

摘要： We present a multi-wavelength study of four high redshift blazars, S5 0014+81 ($z=3.37$), CGRaBS J0225+1846 ($z=2.69$), BZQ J1430+4205 ($z=4.72$), and 3FGL J1656.2$-$3303 ($z=2.40$), using the quasi-simultaneous data from {\it Swift}, {\it NuSTAR}, and {\it Fermi}-Large Area Telescope (LAT) and also the archival {\it XMM-Newton} observations. Other than 3FGL J1656.2$-$3303, none of the sources were known as $\gamma$-ray emitters and our analysis of $\sim$7.5 years of LAT data reveals the first time detection of the statistically significant $\gamma$-ray emission from CGRaBS J0225+1846. We generate the broadband spectral energy distributions (SED) of all the objects, centering at the epoch of {\it NuSTAR} observations and reproduce them using a one zone leptonic emission model. The optical$-$UV emission in all the objects can be explained by the radiation from the accretion disk, whereas, X-ray to $\gamma$-ray window of the SEDs are found to be dominated by the inverse Compton scattering off the broad line region photons. All of them host billion solar mass black holes. Comparing the accretion disk luminosity and the jet power of these sources with a large sample of blazars, we find them to occupy high disk luminosity-jet power regime. We also investigate the X-ray spectral properties of the sources in detail with a major focus on studying the causes of soft X-ray deficit, a feature generally seen in high redshift radio-loud quasars. We summarize that this feature could be explained based on the intrinsic curvature in the jet emission rather than due to external effects predicted in the earlier studies, such as host galaxy and/or warm absorption.