Parkes observations for project P427 semester 2009APRS

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 pulsars in NGC6397 and NGC6266 are primary targets 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), NGC6397 at 10cm (for studying the eclipse region and the orbital secular evolution) and NGC6266 at 20cm (for investigating the cluster's proper motion and dynamics and the eclipsing pulsar). 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 will exploit the new back-ends (APSR and DFB4) now available at Parkes.对P303中发现的12颗脉冲星开展计时观测，可保障获得高质量研究成果：(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，该现象或许源于中等质量黑洞（intermediate-mass black hole）的作用；(b) 位于NGC 6397与NGC 6266星团中的食脉冲星，是研究奇异双星系统晚期演化的核心观测目标。我们提议继续推进现有计时观测项目，重点观测波段与目标分配如下：20厘米波段下的NGC 6752（用于测量额外参数以约束黑洞的存在性）、10厘米波段下的NGC 6397（用于研究食脉冲星的掩食区域与轨道长期演化），以及20厘米波段下的NGC 6266（用于探究该星团的自行、动力学特性及其中的食脉冲星）。我们同时申请观测时长，以开展试点观测工作，用于在一批适配的星团子集中开展有史以来深度最高的毫秒脉冲星搜寻巡天。此次革新后的巡天项目将依托帕克斯望远镜（Parkes）当前已投入使用的新型后端设备APSR与DFB4完成。