Parkes observations for project P427 semester 2009OCTS

Timing the dozen pulsars discovered in P303 is ensuring high quality results: (a) the peculiarities (in position or projected acceleration) of all the 5 millisecond pulsars in NGC6752 suggested the presence of non thermal dynamics in the core, perhaps due to black-holes of intermediate mass; (b) the eclipsing pulsar in NGC6397 is a stereotype for studying the late evolution of exotic binaries. We propose to continue our timing project focusing mostly on NGC6752 at 20cm (in order to measure additional parameters useful to constrain the existence of a black-hole) and NGC6397 at 10cm (for studying the eclipse region and the orbital secular evolution). We also request time for performing pilot observations for a new deeper than ever search for millisecond pulsars in a subset of suitable clusters. This revamped search (as well as the requested timing observations) will exploit the new back-ends (APSR and DFB4) now available at Parkes.

针对P303中发现的12颗脉冲星开展的计时观测工作正保障着高质量研究成果：(a) NGC 6752星团内全部5颗毫秒脉冲星（millisecond pulsar）在位置与投影加速度上的异常特征，暗示其核心区域存在非热动力学过程，该过程或许由中等质量黑洞（black hole）引发；(b) NGC 6397星团中的食脉冲星（eclipsing pulsar）是研究奇异双星系统晚期演化的经典样本。我们提议继续推进计时观测项目，重点聚焦20厘米波段下的NGC 6752星团（以测量额外参数，助力约束黑洞的存在性），以及10厘米波段下的NGC 6397星团（用于研究食区与轨道长期演化）。此外，我们还申请观测时长以开展试点观测，用于在一批合适的星团子样本中开展前所未有的深场毫秒脉冲星搜寻工作。此次优化升级后的搜寻工作（连同本次申请的计时观测项目）将依托帕克斯望远镜（Parkes）目前已启用的新型后端设备APSR与DFB4完成。