Parkes observations for project P1011 semester 2019APRS_05

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.

射电频谱具有曲率或截断等特征的脉冲星，在已知脉冲星样本中属于特殊类群，仅约20%的脉冲星存在这类频谱特征。遗憾的是，除1.4 GHz频段外，可靠的流量密度测量数据往往难以获取，因此无法精准确定这些脉冲星的频谱形态与特征。我们计划利用帕克斯望远镜（Parkes Telescope）新近启用的UWL接收机（UWL Receiver）所具备的独特性能——其覆盖约700至4000 MHz的超宽瞬时频段，以及极高的灵敏度——来测定26颗射电脉冲星的频谱。这些脉冲星此前已被观测到存在频谱特征，或存在相关特征的迹象。此次获取的帕克斯望远镜新观测数据，对于确定该频段内的脉冲星频谱形态、刻画其频谱特征，以及在记录带宽内解析这些特征至关重要。我们的研究目标是厘清这些频谱特征的物理起源：即这类特征究竟是源自脉冲星自身辐射的固有属性，还是由脉冲星磁层内部的吸收过程，或是视线方向上的吸收过程所引发。