Low-frequency radio selection finds radio-bright galaxies regardless of the amount of obscuration by gas and dust. We report Chandra observations of a complete 178 MHz–selected, and so orientation-unbiased, sample of 44 0.5 < z < 1 3CRR sources. The sample is comprised of quasars and narrow-line radio galaxies (NLRGs) with similar radio luminosities, and the radio structure serves as both an age and an orientation indicator. Consistent with unification, intrinsic obscuration (measured by N _H, X-ray hardness ratio, and X-ray luminosity) generally increases with inclination. However, the sample includes a population not seen in high-z 3CRR sources: NLRGs viewed at intermediate inclination angles with N _H < 10²² cm⁻². Multiwavelength analysis suggests that these objects have lower L/L _Edd than typical NLRGs at similar orientation. Thus, both orientation and L/L _Edd are important, and a “radiation-regulated unification” provides a better explanation of the sample’s observed properties. In comparison with the 3CRR sample at 1 < z < 2, our lower-redshift sample shows a higher fraction of Compton-thin NLRGs (45% versus 29%) but a similar Compton-thick fraction (20%), implying a larger covering factor of Compton-thin material at intermediate viewing angles and thus a more “puffed-up” torus atmosphere. We posit that this is due to a range of L/L _Edd extending to lower values in this sample. In contrast, at high redshifts, the narrower range and high L/L _Edd values allowed orientation (and so simple unification) to dominate the sample’s observed properties.

无论气体和尘埃的遮蔽量如何，低频无线电选择都能找到射电明亮的星系。我们报告了 44 个 0.5 < z < 1 3CRR 源的完整 178 MHz 选择的 Chandra 观测结果，因此定向无偏。该样本由具有相似射电光度的类星体和窄线射电星系 (NLRG) 组成，射电结构既可以作为年龄指标，也可以作为方向指标。与统一一致，内在遮蔽（通过N _H、X 射线硬度比和 X 射线光度测量）通常随着倾斜度增加。然而，样品包括在高没有看到一个人口ž 3CRR来源：NLRGs在与中间倾斜角度观看Ñ _ħ <10²² cm ^-2。多波长分析表明，这些物体的L / L _Edd比类似方向的典型 NLRG低。因此，方向和L / L _Edd都很重要，“辐射调节统一”可以更好地解释样品的观察特性。与 1 < z < 2时的 3CRR 样本相比，我们的低红移样本显示出更高比例的康普顿薄 NLRG（45% 对 29%）但类似的康普顿厚分数（20%），这意味着更大的覆盖在中等视角下康普顿薄材料的因素，因此更“膨胀”的环面气氛。我们假设这是由于L的范围/ L _Edd扩展到此示例中的较低值。相比之下，在高红移时，更窄的范围和高L / L _Edd值允许取向（以及如此简单的统一）主导样品的观察特性。