UCL Astrophysics Consolidated Grant 2018-2021

We now know that not only is our Universe expanding, but that it is expanding at an ever-increasing rate. Fuelled by a mysterious driver called Dark Energy, galaxies, such as our Milky Way are rushing away from each other at such enormous acceleration that not even the powerful force of gravity can hold the universe together. Researchers in UCL's Astrophysics Group are testing these discoveries with an ambitious programme of research for the coming years which aims to understand the makeup and evolution of our Universe by looking at comprehensive maps of the sky. But detailed catalogues containing billions of galaxies and other, more exotic objects such as quasars are just the start - at UCL we are leading efforts to turn these catalogues into physical insight. Over the coming years we will be focussing on turning raw data from our surveys into an understanding of, for example, the fundamental physics of the early Universe; the mass of the enigmatic neutrino particle; the nature and distribution of "dark matter" and "dark energy"; and the way in which the cosmos lit up as its first stars and quasars formed. In order to understand how galaxies are made of we will probe how stars form from vast gas and dust clouds and how the chemistry that goes on between the stars affects and controls these crucial processes. We will learn how clouds of gas and dust contract in different ways during the earliest stages of star-formation, and how observations of complex molecules can be used to study the physical processes that are involved. We will also analyse the tracers of newly forming high mass protostars, including the associated jets and outflows. We will not only study molecules and dust in our own Galaxy but also in nearby galaxies, and in distant, very young, galaxies located at the edge of the Universe. Through mechanical, chemical and radiative feedback the influence of massive stars (born with masses greater than 20 solar masses) extends well beyond the confines of their immediate environments, to play a vital role in the wider galactic ecology. To understand this influence we propose to conduct research based on substantial radio and millimetre observational surveys to investigate the key drivers of the evolution of massive stars, including mass-loss via powerful winds and interactions in binary systems. Recent discoveries of exoplanets indicate that almost every star has a planetary system, with Earth just one of several billion planets in our Galaxy. With more than 3,500 exoplanets detected, there are about 40 known super-Earths. All these rocky planets have very short orbits and hence hot atmospheres. Some of these planets are very like our own but very young Earths can have melting rock and steamed-water atmospheres. There is little knowledge about these lava-worlds. What are they made of? Are they ever going to cool down to the temperatures which could sustain life? In recent years, the UCL team has pioneered techniques to extract information about exoplanets from starlight filtered through their atmospheres as they pass in front of their star, which lead to several ground breaking discoveries. To carry out their studies of the heavens UCL's instrument makers are aiming to improve the precision with which larger and more sophisticated ground-based telescopes are designed and assembled and at the same time create lighter and lower cost structures for future infrared telescopes in space that can be used to deliver data of better quality. But all of this will be wasted unless our fellow citizens get to share in the wonder and excitement of our group's work. We will ensure that our team members continue to explain their work through talks and lectures, public events, and the media, inspiring the next generation of scientists, and helping and challenging industry to develop new technologies.