Ultra-fast outflows (UFOs) of plasma from actively accreting galactic nuclei (AGN) are large-scale, mildly relativistic flows of highly ionised material. The interaction of these outflows with the interstellar medium can lead to the formation of collisionless shocks that are potential sites for the acceleration of elementary particles to ultra-high energies ("cosmic rays"). We study the...
Millisecond pulsars (MSPs) are rapidly spinning neutron stars often found in close binary systems with a companion star. Some of these systems, known as spiders, experience a process where the pulsar’s intense radiation gradually strips away material from its companion. These systems are classified into two types: redbacks (RBs), where the companion has a mass between 0.1 and 0.5 times the...
Compact binary millisecond pulsar systems contain a rapidly rotating neutron star, or pulsar, and a companion star. The pulsar wind contains high energy particles that can heat, or irradiate, the companion, and we can observe the effects of this in optical data of the companion. These systems can host the most massive pulsars and to accurately calculate their masses, we model the optical light...
Tidal disruption events are extremely energetic astrophysical transients. They emit radiation in a multitude of wavelength ranges except gamma-rays. The tidal disruption event AT2019azh is a very interesting one as it is one of the closest ones we have observed, and it is also one of the brightest ones. In this talk, I will present what we can learn about the physical properties of AT2019azh...
Compact binary millisecond pulsars (spiders) are short-period binary systems consisting of a millisecond pulsar and a low-mass companion. These systems emit across the entire electromagnetic spectrum and are particularly bright in gamma-rays. Pulsed gamma-ray emission has been observed in many of these systems and is believed to originate from the neutron star's current sheet. Some spiders...
What is the maximum mass of a neutron star, above which it collapses into a black hole? The answer to this seemingly simple question has far-reaching implications for nuclear physics, astrophysics, and the emerging field of gravitational wave astronomy. Despite its importance - particularly in determining the equation of state of ultra-dense matter - this crucial quantity is still poorly...
