Parkes observations for project P1011 semester 2019APRS_07

Pulsars with features in their radio spectra, such as curvature or breaks seem to be special cases among the known pulsar population, with only about 20 per cent exhibiting them. Unfortunately, reliable flux density measurements besides at 1.4 GHz are often unavailable, so that their spectral morphologies and features cannot be determined accurately. We propose to utilize the unique capabilities of the newly commissioned UWL receiver at the Parkes telescope, its extremely wide instantaneous frequency coverage from about 700 to 4000 MHz together with its high sensitivity, to determine the spectra of 26 radio pulsars. These have previously been identified to exhibit spectral features or show hints thereof. The new Parkes data are crucial to determine their spectral morphologies in that frequency range, to characterize their spectral features and to resolve these within the recorded bandwidth. Our aim is to understand the physical origin of the features, namely, whether these are perhaps intrinsic to the pulsar emission in these sources, are caused by absorption processes inside the pulsar's magnetosphere, or along the line of sight.

在已发现的脉冲星群体中，射电频谱存在弯曲或断裂等特征的脉冲星属于特殊类群，仅约20%的脉冲星展现出这类频谱特征。遗憾的是，除1.4 GHz波段外，可靠的流量密度测量数据往往难以获取，导致无法精准确定这类脉冲星的频谱形态与特征。我们提出利用帕克斯望远镜（Parkes telescope）上新启用的UWL接收机（UWL receiver）的独特性能——其拥有约700至4000 MHz的超宽瞬时频率覆盖范围，以及极高的探测灵敏度——来测定26颗射电脉冲星的频谱。这批脉冲星此前已被确认存在频谱特征，或显示出此类特征的潜在迹象。新获取的帕克斯望远镜观测数据，对于确定该频率区间内的频谱形态、刻画其频谱特征，并在记录带宽内解析这些特征而言至关重要。我们的研究目标是阐明这些频谱特征的物理起源：这类特征究竟是源于脉冲星自身的辐射过程，由脉冲星磁层内部的吸收机制所致，还是沿视线方向的吸收过程引发的。