标题： 非常长基线干涉测量对高红移耀变体候选体J0141-5427的观测 显示英文标题

标题： Very long baseline interferometry observations of the high-redshift blazar candidate J0141-5427

摘要： 活动星系核（AGN）已被观测到红移z~7。 它们在研究早期宇宙以及其中心超大质量黑洞的增长方面至关重要。 其喷流以小视角看到的射电明亮AGN被称为耀变体，并显示出相对论增强其辐射。 因此，它们明显更亮的喷流在高红移宇宙中更容易被探测到。 DES J014132.4-542749.9是在z = 5处的一个射电明亮但X射线弱的耀变体候选者。 我们使用澳大利亚长基线阵列在1.7和8.5 GHz频率下对该源进行了高分辨率射电干涉观测。 在两个频率上都检测到了一个单一的紧凑射电源，具有平坦的射电谱。 我们得出了该天体毫角秒级精确的位置。 其亮度温度的频率依赖性与在较低红移处观测到的耀变体源相似。 根据我们的观测，我们可以确认其耀变体特性。 我们将它的射电特性与其他两个同样X射线弱且射电明亮的AGN进行了比较，发现它们表现出非常不同的相对论增强特性。 显示英文摘要

摘要： Active galactic nuclei (AGN) have been observed as far as redshift z~7. They are crucial in investigating the early Universe as well as the growth of supermassive black holes at their centres. Radio-loud AGN with their jets seen at a small viewing angle are called blazars and show relativistic boosting of their emission. Thus, their apparently brighter jets are easier to detect in the high-redshift Universe. DES J014132.4-542749.9 is a radio-luminous but X-ray weak blazar candidate at z = 5. We conducted high-resolution radio interferometric observations of this source with the Australian Long Baseline Array at 1.7 and 8.5 GHz. A single, compact radio emitting feature was detected at both frequencies with a flat radio spectrum. We derived the milliarcsecond-level accurate position of the object. The frequency dependence of its brightness temperature is similar to that of blazar sources observed at lower redshifts. Based on our observations, we can confirm its blazar nature. We compared its radio properties with those of two other similarly X-ray-weak and radio-bright AGN, and found that they show very different relativistic boosting characteristics.