Parkes observations for project P1381 semester 2025OCTS_04

The Galactic bulge is theorized to host a rich population of millisecond pulsars (MSPs), but direct detections have been severely hampered by high interstellar scattering, dispersion, and background noise near the Galactic center. These MSPs, if confirmed, would serve as powerful tools for testing gravity, studying dense matter, and probing gravitational waves. A key indirect tracer of this population is the Fermi GeV excess (FGE), an unresolved gamma-ray signal possibly originating from thousands of faint MSPs. However, the lack of direct detections has limited our ability to test this hypothesis.\n The MeerKAT Galactic Bulge Survey (MGBS) is the most sensitive pulsar search yet of this region, targeting the bulge MSP population. Early results from MGBS have already revealed several promising MSP candidates. We propose to use Murriyang to conduct targeted follow-up observations of three of the most compelling candidates from MGBS. Our goals are to confirm the pulsations, refine key parameters such as spectral indices and orbital characteristics, and strengthen their association with the bulge.\n Confirming even a handful of bulge MSPs would have wide-reaching impact: constraining the origin of the FGE, testing dark matter interpretations, refining models of Galactic structure, and improving predictions for low-frequency gravitational wave backgrounds. This proposal is a critical next step toward establishing a long-sought bulge MSP population and unlocking new physics from the inner Galaxy.

银河系核球（Galactic bulge）理论上孕育有数量众多的毫秒脉冲星（millisecond pulsars, MSPs）种群，但受限于银心附近强烈的星际散射、色散与背景噪声，相关直接探测工作长期受到严重阻碍。若能证实该区域存在此类毫秒脉冲星，它们将成为检验引力理论、研究致密物质以及探测引力波的强力工具。该种群的关键间接示踪物是费米GeV超出（Fermi GeV excess, FGE）——一种未分辨的伽马射线信号，其来源可能为数千颗微弱的毫秒脉冲星。然而，直接探测的缺失限制了我们对这一假说的验证能力。
MeerKAT银河系核球巡天（MeerKAT Galactic Bulge Survey, MGBS）是当前针对该区域最为灵敏的脉冲星搜寻项目，目标直指核球毫秒脉冲星种群。MGBS的早期探测结果已发现多颗极具潜力的毫秒脉冲星候选体。我们提议利用Murriyang对MGBS筛选出的3个最具说服力的候选体开展靶向后续观测，目标为确认脉冲信号、精化谱指数与轨道特性等关键参数，并强化这些候选体与银河系核球的关联性。
即便仅证实少量核球毫秒脉冲星，也将产生广泛影响：约束费米GeV超出的起源、检验暗物质相关解释、完善银河系结构模型，以及改进低频引力波背景的预测结果。本提案是建立长期以来备受追寻的核球毫秒脉冲星种群、并从银河内部解锁新物理的关键下一步。