Hertfordshire Astronomy 2018-2021

The Centre for Astrophysics Research carries out observational programmes spanning the wavelength range from X-ray to radio -- supporting this by computer modelling and simulation. Our research ranges from observations of high-redshift galaxies at long wavelengths through to novel statistical analyses of observations seeking to detect planets outside our Solar System. In between these extremes, we carry out the largest multi-wavelength surveys conducted to date to understand the properties of the Milky Way. Our research makes use of observations from all of the main European and international astronomical observatories, including ground-based observatories at optical, radio and submillimetre wavelengths, and space observatories at wavelengths ranging from the far infrared to X-rays. Computer simulations gives us a better understanding of the physical processes detected in our observations, and we need to apply advanced data-mining techniques to work with the ~terabyte datasets we are generating. Below is a brief description of our research in each of these areas.

We perform searches of nearby stars to discover planets, and are world leaders in the application of radial-velocity methods for this purpose; our focus in the grant period will be the planet populations around Sun-like nearby stars. We also discover, follow up and model the properties of the coolest brown dwarfs whose temperatures overlap with those of planets. These studies aim to understand the diversity of the population of brown dwarfs detected with the Gaia satellite and to establish how their modes of formation fit in with those of their brethren of different masses, i.e. heavier (stars) or lighter (planets).

The Milky Way is our home galaxy. Material within it, in the form of gas and dust, is the raw material for forming stars and planetary systems. At the end of stellar lives some of this material remains locked up in stellar remnants but much of it is returned in late superwind phases and supernova explosions. The cycle between accretion in youth and outflow in old age enriches the gaseous medium and governs its dynamics, via the thermal and mechanical energy injected into the gas. By using large area imaging surveys, our research looks at how gas, dust and stars within the Milky Way are connected, and at the details of how stars are formed. Our surveys span the optical to radio domains, tracing stars, extinction, molecular clouds, their dust properties and associated star formation.

Looking beyond the Milky Way, it is possible to appraise how stars form and evolve in different environments, from small dwarf galaxies to the outer parts of other galaxies like our own. We study the gas content of galaxies, providing the material for star formation, and link what we find to stellar populations and to star forming regions in the full range of local galaxies. By understanding the processes that trigger star formation and stellar evolution in the nearby Universe, we can apply this understanding to the very earliest galaxies and the first generations of stars in the distant Universe. Indeed some of our work focuses on high-redshift galaxies detected with great efficiency at sub-millimetre wavelengths, making use of cutting-edge instruments such as ALMA.

A new generation of surveys is mapping out the most distant galaxies, and allows us to investigate what links the processes of star formation and the growth of supermassive black holes. We also use detailed radio and X-ray observations, along with computer modelling, to measure the energy injected by jets ejected from supermassive black holes into distant galaxies and clusters of galaxies, affecting star formation and gas properties, and playing a long-term role in their evolutionary history. The evolution of the chemical elements in these galaxies, and the interplay between black-hole activity and elemental abundances, is a particular focus of this proposal.

We identify three classes of beneficiaries from this research:

1) academic beneficiaries

2) the general public and particularly teachers and pupils in schools locally and nationally through our outreach and public engagement programme.

3) industry, directly through collaborations / technology transfer, indirectly through our training of undergraduate and graduate students.

For academic beneficiaries see the relevant section of the proposal.

Our outreach and public engagement programme is very strongly driven by the cutting-edge research funded by the STFC grant. Elements of this include (i) public open evenings at the Bayfordbury observatory, which generally have a research-based theme; this reaches local people, particularly families, which is important as parents, along with teachers, are most influential in the career choice of young people. (ii) Observatory group visits from a very wide range of groups, again often including young people. (iii) 'Cutting-edge astronomy' courses delivered to teachers, allowing teachers to better understand some of the concepts they teach, and giving them increased confidence to deliver the material in their classes. (iv) Schools outreach, engaging large numbers of pupils in local schools with the research activities of the group. In addition, we access the wider public through national and international print media, websites, popular books, TV and radio appearances and so on.

We have close links with various commercial organizations, such as Airbus Defence and Space a few miles away in Stevenage, with whom we have in the past collaborated on project proposals, and GES Ltd, the commercial organization developing the Goonhilly Earth Station for various purposes including public engagement and radio astronomy use. These contacts necessarily rely on the cutting-edge science and technical skills supported by STFC.