Parkes observations for project P965 semester 2018APRS_02

The deployment of the new ultra-wide-band receiver UWL enables a plethora of experiments which were previously not possible or very difficult. One immediate benefit for pulsar timing studies is the significantly increased ratio of available radio frequency bandwidth to the decorrelation bandwidth as induced by the ionised interstellar medium (ISM). PSR J1933-6211 is a strongly-scintillating millisecond pulsar. Due to its scintillation, previous studies failed to measure the mass and orbital parameters of this system and instead provided limits. With the UWL we expect more reliable detection of bright scintles during every observation; and hence improved and reliable timing precision that will allow a mass measurement through Shapiro-Delay detection. As an additional benefit, we can use the broad band to adequately study the scintillation properties of this pulsar and thereby constrain its orbital inclination. \r\n The mass of the pulsar is potentially the lowest known, depending on the type of its white dwarf companion. By measuring it we will also determine the type of the white dwarf which is interesting in its own right and is one of the coolest such objects known (Antoniadis, priv. comm.). Finally, we will verify if, as we expect, the precision attainable with the increased bandwidth is sufficient for high-precision pulsar timing and inclusion of PSR J1933-6211 in pulsar timing array experiments.

新型超宽带接收机UWL（Ultra-Wide-Band Receiver）的部署，使得此前无法开展或难度极高的大量实验得以实现。脉冲星计时研究的一项直接益处，是可用射频带宽与电离星际介质（Ionised Interstellar Medium, ISM）所诱导的去相关带宽的比值得到显著提升。PSR J1933-6211是一颗强闪烁毫秒脉冲星（millisecond pulsar）。受其闪烁效应影响，此前的研究未能测得该双星系统的质量与轨道参数，仅能给出相关限制。借助UWL，我们有望在每次观测中更可靠地探测到明亮的闪烁亮点；进而获得更精准可靠的计时精度，从而可通过夏皮罗延迟（Shapiro-Delay）探测实现质量测量。此外，我们还可利用该宽带接收机充分研究该脉冲星的闪烁特性，以此约束其轨道倾角。
该脉冲星的质量有可能是目前已知最低的脉冲星质量之一，具体数值取决于其白矮星伴星（white dwarf companion）的类型。通过对该质量的测量，我们还可确定其白矮星伴星的类型——这一研究本身就具有重要科学价值，且该白矮星是目前已知温度最低的此类天体之一（安托尼亚迪斯，私人通信）。最后，我们将验证：通过提升带宽所获得的计时精度，是否如我们预期的那样，足以支撑高精度脉冲星计时研究，并可将PSR J1933-6211纳入脉冲星计时阵列（pulsar timing array）实验。