Parkes observations for project P1317 semester 2024APRS_03

The existence of a population of millisecond pulsars (MSPs) in the Galactic bulge is supported, among others, by the Fermi GeV excess, a signal of gamma rays coming from the Galactic center (GC) direction and resembling the cumulative emission of known MSPs. A previous study showed that, while these MSPs are unresolved in gamma rays, some of them could have been detected in past X-ray observations. The authors also identified a large number of MSP candidates among unidentified X-ray sources. By analyzing unpublished radio images, we found interesting radio counterparts to 6 of those candidates, and were granted 20h of observations with the Green Bank Telescope to settle on their nature. We discovered a new MSPs, PSR J1740-2807, towards one of our X-ray targets, bringing to 3 the number of highly-dispersed MSPs in the GC direction and probably unveiling the first direct evidence of a bulge MSP population. We propose to carry out regular timing of this pulsar with Parkes, in order to reveal its properties and potentially claim association with the original X-ray source. The follow up of this source will have a major impact on our understanding of the Fermi GeV excess, but will also benefit the main questions of modern physics like the nature of dark matter, possibly annihilating into gamma rays in the Galactic center, and the equation of state of cold dense matter, which can be constrained from X-ray observations of MSPs.