Parkes observations for project P1334 semester 2024OCTS_05

The Galactic Centre is the most complex and dynamic region of our Galaxy. Radio images have revealed a plethora of filamentary structures that trace out magnetic fields running perpendicular to the Galactic plane. Exactly what powers the radio emission of these filaments had remained a mystery, until the serendipitous discovery of a pulsar embedded in one. With a spin-period of 8.4 ms, PSR J1744-2946 is the first ever millisecond pulsar to be discovered in the central region of our Galaxy. While an exciting discovery in its own right, the limited timing baseline leaves open several unanswered questions: How efficiently is the pulsar injecting energy into the radio filament? Could the pulsar be included in pulsar timing array experiments? And can it be used as a key component in the search for axion dark matter? In this proposal we will use the Ultra-Wideband Low receiver system on Murriyang to conduct regular, monthly observations of PSR J1744-2946. This will provide us with a measurement of the pulsar spin-down rate and a sense of its long-term stability, thereby providing answers to the questions posed above.

银河系中心（Galactic Centre）是银河系中最为复杂且动态性最强的区域。射电图像已揭示出大量丝状结构，这些结构勾勒出垂直于银道面（Galactic plane）的磁场分布。此前，这类丝状结构的射电辐射究竟由何种机制供能，长期以来一直是未解之谜，直至科研人员在其中一处丝状结构内偶然发现了一颗脉冲星。该编号为PSR J1744-2946的脉冲星自旋周期为8.4毫秒，是人类首次在银河系中心区域发现的毫秒脉冲星（millisecond pulsar）。尽管这一发现本身已令人振奋，但有限的计时基线仍留下诸多悬而未决的问题：该脉冲星向射电丝状结构注入能量的效率究竟有多高？它能否被纳入脉冲星计时阵列（pulsar timing array）实验？此外，它能否作为关键组分用于轴子暗物质（axion dark matter）的搜寻研究？在本研究提案中，我们将利用Murriyang射电望远镜上的超宽带低接收机系统（Ultra-Wideband Low receiver system），对PSR J1744-2946开展每月一次的常规观测。此次观测将帮助我们测得该脉冲星的自转减速率，并掌握其长期稳定性特征，从而为上述所有问题提供明确解答。