2023-12-22 Abstract

Title: Studying fundamental physics and astrophysics using millisecond pulsars around a massive black hole

Speaker: Prof. Kinwah Wu (UCL)
 
Date: December 22 at 14:30
 
Location: R521, General Building II
 
Abstract:
Systems containing a massive black hole with millisecond pulsars (MSP) are useful apparatus for the study of fundamental physics and astrophysics. Extreme-mass-ratio
(EMR) systems containing two compact objects are key targets of LISA, and EMR systems in which one or two MSPs orbiting around a black hole are by nature multi-messenger sources. They have distinguishable signatures in the gravitational waves and the electromagnetic waves that they emit. It was recently recognised that systems with multiple MSP can be used to resolve certain important astrophysical problems unexpectedly. In this colloquium I will demonstrate how we can use these systems (1) to determine spin-curvature coupling in strong gravity, (2) to investigate gravito-magnetism and non-linear relativistic dynamics in hierarchical 3-body systems and (3) to map the spatial distribution of baryons in the diffuse media around a nuclear black hole in a galaxy using neutrino imaging. The corresponding systems appropriate for the studies in these three cases are (1) EMR binaries containing a massive black hole and one MSP, (2) a tightly bounded MSP pair in a relativistic orbit around a massive black hole, and (3) a cluster of MSP in the vicinity of the massive black hole at the Galactic Centre, which is known to be surrounded by a diffuse molecular torus. In each case, I will explain the theories behind it and discuss the observational prospects in the very near future using the new generation multi-messenger instruments.