Parkes observations for project P1011 semester 2019APRS_14

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.

在已知的脉冲星群体中，射电频谱呈现曲率或谱断等特征的脉冲星属于特殊类群，仅约20%的脉冲星拥有此类特征。遗憾的是，除1.4 GHz频段外，通常难以获取可靠的通量密度测量数据，因此无法精准确定它们的频谱形态与特征。我们计划利用帕克斯望远镜上新启用的UWL接收机（UWL receiver）的独特性能——其覆盖约700至4000 MHz的超宽瞬时频率范围与极高灵敏度——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此类特征的迹象。帕克斯望远镜的这批新观测数据对于确定该频率范围内的频谱形态、表征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特征的物理起源：即这些特征究竟是源自此类源中脉冲星辐射的本征属性，还是由脉冲星磁层内部或视线方向上的吸收过程所引发。