Astronomy at Queen Mary 2023-2026

Lead Research Organisation: Queen Mary University of London
Department Name: Astronomy Unit

Abstract

-- The early universe underwent a period of accelerated inflation generating density fluctuations sourcing the distribution of galaxies. We will model inflation numerically to calculate the gravitational wave background due to these density fluctuations and the amount of black holes formed when these small density fluctuations collapse completely.

-- Tests of Einstein's theory of gravity are becoming possible in a range of exciting new systems, from the largest scales in the Universe to distant astrophysical systems. We will create ways of combining new observations with local tests to gain the best constraints on gravity, over a vast range of spatial and temporal scales.

-- Large-scale structure surveys will map the universe on scales large enough to detect new relativistic effects. These contaminate primordial signals of inflation, but also provide new opportunities for testing general relativity. We will investigate new simulations to understand these in the distribution of galaxies.

-- We will investigate the gravitational dynamics of the early Universe in theories of gravity with higher derivative corrections and study their impact on inflationary spacetimes. These corrections generically arise from theories of quantum gravity so are critical in the early Universe.

-- Measurements of velocities of wide binary stars can discriminate modified gravity vs dark matter. We will perform new observations and modeling of critical high-velocity systems in developing this test.

-- The early Universe was filled with neutral hydrogen gas, and by mapping the distribution we can model the first stars. We will develop new ways to separate the very faint radio emission from neutral hydrogen from much brighter emission from our own galaxy and others.

-- Planet formation occurs in the discs of gas and dust that are found around young stars. We will develop models of these discs and examine how embedded planets interact with them, in order to understand how the orbits of the planets change and how they accrete mass from the surrounding disc as they grow.

-- Building km-sized planetesimals is a race against time. Pebbles of cm-m in size drift towards the star at high speed, so collecting them into planetesimals needs to proceed quickly. We will perform detailed simulations to determine if planetesimals can form this way.

-- Massive stars in planet-forming clusters emit copious amounts of UV radiation that heat and disperse planet-forming discs. We will develop 3D simulations of how these discs are irradiated and stripped of material with ground-breaking implications for planetary birth environments.

-- Young transiting planets offer a window onto the formation and early evolution of planetary systems. We will measure young planet masses, characterise their atmospheres, unravel their dynamical histories, and determine their ages to provide new insights into their formation and early evolution.

-- We will characterise dark matter structures that form in strong gravity environments around black holes using simulations of relativistic particles in full general relativity. We will investigate the effects of eccentricity, spin, and unequal mass ratios on the dark matter cloud that is accreted.

-- We will develop a new strategy for the study of black holes by looking at how far away they are from a symmetric state. This approach will be tested in state-of-the art numerical simulations of black holes with the aim of extracting new information from available observations.

-- Understanding neutron stars and other very dense stars and their collisions requires intricate modeling of fluids in full general relativity. This is extremely complicated, especially at the surface of these bodies. We will formulate new schemes to solve this problem, building new simulations to test our approach.