Parkes observations for project P1129 semester 2022OCTS_04

PSR J0837$-$2454 is a young, high-Galactic-latitude pulsar, whose distance derived from dispersion measure (DM) implies a height of $>$1~kpc above the Galactic plane. The young age (28kyr) and position can be explained if (i) the pulsar was born at this high Galactic $z$-height from a runaway or walkaway O/B star; or (ii) the DM-derived distance to this pulsar is incorrect and the pulsar is closer to the plane of the Galaxy. VLBA observations will provide us with an estimate of the proper motion of the pulsar, along with the distance to the pulsar through a measurement of the parallax if the pulsar is closer than the DM implies. These measurements are crucial to determining whether or not this pulsar represents the remnants of a rare Milky Way halo O/B star. This proposal seeks to continue monitoring this pulsar in order to maintain phase connection of the timing solution throughout the duration of planned VLBA observations. This is crucial for conducting gated observations with the VLBA, but will also contribute to studies of the pulsar's emission properties and the ISM along the line-of-sight to the pulsar.

PSR J0837−2454是一颗年轻的高银道纬度脉冲星，其通过色散量（dispersion measure, DM）推算得到的距离显示，它位于银道面上方超过1千秒差距（kpc）的位置。该脉冲星的年轻年龄（28 kyr）与所处位置可通过两种假说解释：其一，该脉冲星诞生于当前的高银道z向高度处，源自一颗逃逸或超逃逸O/B型恒星；其二，通过色散量推导得到的该脉冲星距离有误，其实际位置更靠近银道面。甚长基线阵列（Very Long Baseline Array, VLBA）观测将为我们提供该脉冲星的自行测量结果，若其实际距离比色散量推算值更近，还可通过视差测量获取其精确距离。此类测量对于判断该脉冲星是否属于罕见的银河系晕O/B型恒星遗迹至关重要。本观测提案旨在持续监测该脉冲星，以在规划中的甚长基线阵列观测全程维持计时解的相位连续性。这一要求对于开展甚长基线阵列的选通观测不可或缺，同时也将为该脉冲星的辐射特性研究以及沿观测视线方向的星际介质（Interstellar Medium, ISM）研究提供重要支撑。