Survey Cosmology

This rolling grant is to support the new observational cosmology group at the Institute of Cosmology and Gravitation (ICG) at the University of Portsmouth. The ICG was only formed in 2002 but has seen rapid growth, driven by strategic investments by the university and funding agencies in the UK and Europe. In total, the ICG now has 10 staff members, 11 postdoctoral researchers, and 17 PhD students from around the world, working on both theoretical and observational cosmology. Cosmology is experiencing a golden age of discovery driven by new advances in technology and theory. However, we are still facing two fundamental challenges before a complete theory of the Universe can be achieved: i) What are the properties of the dark matter and dark energy that make up 96% of the Universe, and ii) how do galaxies - the 'building blocks' of the Universe - form and evolve? This rolling grant will address both these problems through the use of new, massive surveys of the sky. For example, we will use a new 520-megapixel camera on the Blanco 4-meter telescope in Chile to digitally image the southern sky. This survey - known as the Dark Energy Survey (DES) - will allow us to measure the clustering of galaxies to high precision, detect the weak gravitational lensing of distant galaxies by the foreground dark matter, and discover thousands of distant supernovae (exploding stars). Taken together with the Sloan Digital Sky Survey and other data, we expect to measure the density of dark energy over 70% the age of the Universe. This will tell us if it is just a constant, as first proposed by Einstein, or something more exotic like quintessence, phantom energy or extra dimensions! This data will also shed light on the properties of dark matter, which we can 'see' via gravity but does not shine like normal matter. In addition to new optical cameras, we plan to harness the power of the next generation of radio telescopes that are being built. The first of these is LOFAR, which will have base stations spread across Europe forming an effective radio telescope over 600 kilometers in size. We will use LOFAR, in conjunction with new data from the SDSS, to study the effects of supermassive black holes on the evolution of elliptical galaxies. The energetic outflows from these black holes has been proposed as a way to slowing down the growth of such galaxies, making them 'red and dead' today. Likewise, we will study the properties of disk galaxies with cosmic time and location to determine what is encouraging them to form new stars today. Together, these studies will help us determine the important physics that drive galaxy evolution. In addition to research, the ICG staff are dedicated to publishing their data to the world. We plan to continue this work by providing the scientific community with access to state-of-the-art data archives using the latest web-services technology. The ICG staff are also committed to public outreach and have been engaged in a number of visible activities in the media and local schools. For example, our students and postdocs have visited local schools to discuss their careers and express the fun of doing research. Finally, the ICG is a close-knit community that provides a strong support infrastructure for the training and mentoring of students and faculty alike.