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Synopsis

Neutron stars are a unique laboratory for probing physics under the greatest extremes of density and gravity, far beyond what is capable in terrestrial laboratories.  This project aims to use gravitational wave discoveries and electromagnetic observations of neutron stars to examine fundamental physics.

Description

When a star exhausts its nuclear fuel, it may collapse to form a black hole, a white dwarf, or a neutron star. Neutron stars are incredibly dense. Their masses are typically 1-2 times that of the Sun, but compress that mass into a volume about 20 kilometres in diameter -- about the distance from Woden to Amaroo! Inside a neutron star, the density of matter may be up to 10 times denser than ordinary atomic nuclei. Studying neutron stars is the only way to learn about the physics of matter under the most extreme conditions.

To gain new insights into fundamental physics from neutron stars, we need to combine astronomical observations with theoretical modelling. Observations may be electromagnetic emission from radio and X-ray pulsars, or gravitational wave detections of colliding neutron stars (and perhaps, in the future, continuous gravitational waves from rapidly-spinning neutron stars). Modelling starts with an assumed equation of state -- the fundamental relationship between density and pressure -- and may include other effects such as the star's strong magnetic field.

The Centre for Gravitational Astrophysics is building new methods for understanding neutron stars using electromagnetic and gravitational wave observations. Recent work has led to a number of student-led publications [1,2].

[1] N. Lu, K. Wette, S. M. Scott, A. Melatos, Mon. Not. R. Astron. Soc. 521, 2103 (2023)
[2] Y. Hua, K. Wette, S. M. Scott, M. D. Pitkin, Mon. Not. R. Astron. Soc. 527, 10564 (2024)

Required background

PHYS3203/6203 (General Relativity).  PHYS3105/PHYS6105 (Physics of Matter) is desirable, although not required.

Experience programming in Python is essential. Experience with UNIX-based operating systems, and programming in C / C++ / Mathematica is desirable.

Research fields