Parkes observations for project P897 semester 2015OCTS

Modulation of pulse times of arrival (TOAs) from pulsars often heralds excitement: planetary companions, neutron star free precession, and the poorly understood but crucially important process of magnetospheric state switching can all produce quasi-periodic TOA modulation. In a sample of 150 young pulsars, we have detected periodic modulation in six pulsars. We propose to obtain multi-epoch, deep, well-calibrated 10 cm pulse profiles to search for profile variability, particularly variability correlated with TOA modulation. The absence of such variation may lend credence to a planet interpretation, while detection will help characterize the magnetospheric states and determine if free precession plays a role. Because the pulsars are largely southern sky objects, and because the 10cm band is largely free from RFI and scattering, Parkes is uniquely capable to deliver this science.

对脉冲星脉冲到达时间（TOAs）的调制往往预示着重要的科学发现：行星伴星、中子星自由进动，以及这一尚不明确却至关重要的磁层状态切换过程，均可产生准周期的TOA调制信号。在150颗年轻脉冲星的样本中，我们已在6颗脉冲星中探测到周期调制信号。本研究拟获取多历元、深曝光且经过良好校准的10厘米波段脉冲轮廓，以搜寻脉冲轮廓的变异性，尤其是与TOA调制相关的变异性。若未观测到此类变化，将可为行星伴星假说提供佐证；若探测到此类变化，则有助于表征磁层状态，并判断自由进动是否在其中发挥作用。由于这批脉冲星大多位于南天天区，且10厘米波段受射频干扰（RFI）和星际散射的影响极小，帕克斯（Parkes）望远镜具备开展此项科研工作的独特优势。