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.
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.
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.
