PKS 1934-638 pc尺度结构的演化再访：使用ASKAP和新西兰望远镜的第一次科学
Evolution of the pc-scale structure of PKS 1934-638 revisited: first science with the ASKAP and New Zealand telescopes
摘要：
我们已经研究了原型千兆赫峰频谱射电星系，PKS 1934-638，使用澳大利亚长基线阵列，增加了两个新的望远镜，大大提高了阵列的角分辨率。这些VLBI观测代表了新西兰新天线和澳大利亚SKA探路者（ASKAP）的第一个天线的第一个科学结果。一个紧凑的双射电源，PKS 1934-638，已被监测了40年，这里描述的观测提供了最新的数据，8年后的前一次观测，以帮助源结构的长期演变的研究。我们利用这些新的长基线探测PKS 1934-638在相对较低的频率为1.4 GHz，以检查的光学深度上的射电源的结构的影响。光学深度效应，导致观察到的频率相关的结构，以前可能被解释为一个扩展的源作为时间的函数。为了估计PKS 1934-638的年龄，扩展和频率依赖效应对于解开纠缠是重要的。我们表明，频率依赖的结构效应可能是重要的PKS 1934-638，并提出了一个简单的二维同步辐射源模型，其中考虑到由于同步辐射自吸收的不透明度的影响。因此，射电源扩展超过40年的证据是薄弱的，这对射电源的估计年龄产生了影响。
英文摘要：
We have studied the archetypal Gigahertz Peaked Spectrum radio galaxy, PKS 1934-638, using the Australian Long Baseline Array, augmented with two new telescopes that greatly improve the angular resolution of the array. These VLBI observations represent the first scientific results from a new antenna in NZ and the first antenna of the Australian SKA Pathfinder (ASKAP). A compact double radio source, PKS 1934-638, has been monitored over a period of 40 years, and the observation described here provides the latest datum, eight years after the previous observation, to aid in the study of the long-term evolution of the source structure. We take advantage of these new long baselines to probe PKS 1934-638 at the relatively low frequency of 1.4 GHz, in order to examine the effects of optical depth on the structure of the radio source. Optical depth effects, resulting in the observation of frequency dependent structure, may have previously been interpreted in terms of an expansion of the source as a function of time. Expansion and frequency dependent effects are important to disentangle in order to estimate the age of PKS 1934-638. We show that frequency dependent structure effects are likely to be important in PKS 1934-638 and present a simple two-dimensional synchrotron source model in which opacity effects due to synchrotron self-absorption are taken into account. Evidence for expansion of the radio source over 40 years is therefore weak, with consequences for the estimated age of the radio source.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
