Parkes observations for project P1152 semester 2022APRS_13

A large population of millisecond pulsars (MSPs) is expected in the Galactic bulge and is supported, among others, by the existence of a spatially extended gamma-ray excess emission discovered in Fermi-LAT data towards the inner Galaxy. Discovering MSPs in the Galactic bulge, would be a major breakthrough with strong impact onto several fields. In Berteaud et al. [2021a, 2021b], we have designed a new method to select bulge MSP candidates among Chandra X-ray cataloged sources. We also analysed imaging data of the VLA and identified 5 potential bulge MSP candidates, detected both with Chandra and VLA. Here we propose to follow up these 5 sources with the UWL receiver system on Parkes, which has the unique potential of probe their MSP nature thanks to multi-band, deep, observations. With the requested time, for two high-priority candidates, we will be able identify any bulge MSP with a pulse period P > 1 ms. Three targets at lower priority can be identified as bulge MSP if their period is larger than 4 ms. Our goal is to provide the first multi-wavelength diagnostics of bulge MSPs, gather information about the MSP/pulsar ratio among the bulge X-ray candidates, and, finally, unveil the nature of the mysterious Fermi-LAT excess.

银心核球中预计存在大量毫秒脉冲星（MSP），这一推测得到了费米伽马射线空间望远镜（Fermi-LAT）数据的支持——该数据在银河系中心区域发现了空间延伸的伽马射线超额辐射。在银心核球中发现毫秒脉冲星（MSP）将是一项重大突破，对多个领域产生深远影响。Berteaud等人（2021a，2021b）设计了一种新方法，用于在钱德拉X射线（Chandra X-ray）编目源中筛选核球MSP候选体。我们还分析了甚大阵（VLA）的成像数据，识别出5个潜在的核球MSP候选体，这些候选体同时被钱德拉和VLA探测到。本文提出利用帕克斯望远镜（Parkes）上的超宽带接收器系统（UWL）对这5个源进行后续观测；凭借多波段深度观测能力，该系统具备探测其MSP本质的独特潜力。若获得申请的观测时间，对于两个高优先级候选体，我们将能够识别出脉冲周期P>1毫秒的所有核球MSP；对于三个低优先级目标，若其周期大于4毫秒，则可被确认为核球MSP。我们的目标是首次提供核球MSP的多波长诊断，收集核球X射线候选体中MSP与脉冲星的比例信息，并最终揭示费米-LAT神秘超额辐射的本质。