Parkes observations for project P1011 semester 2019APRS_11

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.

射电频谱存在曲率、突变等特征的脉冲星，在已知脉冲星种群中属于特殊类群，仅约20%的脉冲星展现出此类频谱特征。遗憾的是，除1.4 GHz频段外，可靠的射电流量密度测量数据往往较为匮乏，因此难以精准确定这些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）上新投入运行的UWL接收机（UWL receiver）的独特性能——其覆盖约700 MHz至4000 MHz的超宽瞬时频带与极高灵敏度——来测定26颗射电脉冲星的频谱。这些脉冲星此前已被确认存在频谱特征或存在此类特征的迹象。本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，并在记录带宽内解析这些特征至关重要。我们的研究目标是阐明此类频谱特征的物理起源，即这些特征究竟是源于这类源的脉冲星辐射固有属性，还是由脉冲星磁层内部或视线方向上的吸收过程所引发。