Ultra-deep ATCA Imaging of 47 Tucanae Reveals a Central Compact Radio Source

A team of astronomers led by Alessandro Paduano (ICRAR/Curtin) have published the results of an ultra-deep radio continuum survey, containing 480 hr of observations, of the Galactic globular cluster 47 Tucanae with the Australia Telescope Compact Array. This comprehensive coverage of the cluster allowed the team to make the deepest radio image of a globular cluster, and the deepest image ever made with the Australia Telescope Compact Array. A faint radio source, ATCA J002405.702-720452.361, was found coincident with the cluster centre and potentially associated with a faint X-ray source. The most plausible explanations are that the source is an undiscovered millisecond pulsar or a weakly accreting black hole. If the X-ray source is associated with the radio source, this would suggest black hole mass somewhere between 54 and 6000 times the mass of our Sun, indicating an intermediate-mass black hole or a heavy stellar-mass black hole.

Added by Phil Edwards on 2024-01-25