Parkes observations for project P1005 semester 2020APRS_01

We propose to conduct observations of PSR J1812-15, a of 1-s pulsar which exhibits both nulling behaviour and clear evidence of acceleration, suggesting that it is in a binary system. Binary pulsars are valuable objects of scientific study, allowing for a wide range of applications, including tests of gravity, probes of the neutron star equation of state and fossil records of stellar evolution. Long spin-period pulsars in binary systems are generally much rarer than faster-spinning recycled pulsars, and represent an under-explored region of pulsar binary evolution.\r\n\r\nDue to the nulling behaviour of PSRs J1812-15, determination of an orbital or phase-connected solution has so far proved impossible, but both of these steps are vital in allowing for the pulsar’s continued study. We propose a targeted, high-cadence observing campaign designed to map the orbits of this pulsar while simultaneously factoring in the redundancy required in order to overcome its nulling behaviour. By studying this pulsar, we hope to provide new insight into an unusual class of pulsar binary, as well to constrain the nulling properties of the pulsar.

我们提出针对PSR J1812-15开展观测研究。该天体是一颗周期约1秒的脉冲星（pulsar），同时表现出消零行为（nulling behaviour）与明确的视加速度证据，表明其隶属于双星系统（binary system）。脉冲双星是极具科学价值的研究对象，可应用于诸多研究领域，包括引力理论检验、中子星物态方程（neutron star equation of state）探测以及恒星演化化石记录研究。双星系统内的长自旋周期脉冲星，其丰度远低于快速旋转的再循环脉冲星（recycled pulsars），代表了脉冲双星演化领域中尚未被充分探索的研究区域。

受限于该脉冲星的消零行为，迄今为止无法确定其轨道解或相位连接解（phase-connected solution），但这两类解对于该脉冲星的后续持续研究至关重要。为此我们提出一项靶向高观测频次观测计划，旨在测绘该脉冲星的轨道参数，同时通过设计必要的冗余观测方案以克服消零行为带来的观测阻碍。通过对该脉冲星的研究，我们期望为一类特殊的脉冲双星系统提供全新的科学认知，并同时约束该脉冲星的消零特性。