Research

Academics: Stephen Serjeant, Glenn White

Visiting Research Fellows:  Chris Pearson

Postdoctoral Research Fellows: Mattia Negrello, Robin Barnard

PhD Students:  Rosalind Hopwood

The Observational Astronomy group specialises in extragalactic surveys of star-forming galaxies in the nearby and distant Universe.

Our major projects include:  

·         The JAXA/ESA AKARI Space Telescope. AKARI is conducting an all-sky far-infrared survey, which like IRAS before it will have an enormous scientific legacy. We are guaranteed time holders. Through the UK-NL AKARI consortium we have access to AKARI’s ground-breaking all-sky survey, leading many areas including rare AGN and extended galaxies, and Pearson also leads the AKARI guaranteed time follow-ups of well-studied Spitzer fields. We have several open time projects, including AKARI’s deepest mid-infrared imaging through the gravitational lensing cluster Abell 2218. Serjeant, White and Pearson are also leading several radio and optical follow-ups of AKARI’s deep blank-field surveys at the Ecliptic Poles. We co-won the 2004 Daiwa Adrian prize for this work.

·         The ESA Herschel Space Observatory. This far-infrared and submm space observatory is due for launch in late 2008. We are members of many guaranteed and open time projects. In particular we co-lead two of the six major science themes of the Herschel ATLAS key project: gravitational lensing (Negrello) and rare objects (Serjeant). Serjeant is also co-leading a proposed eMERLIN key programme on gravitational lensing which in part follows up the ATLAS lens catalogue.

·         The ESA Planck Surveyor. We are part of Working Group Six on extragalactic point sources, and have co-led their collaboration with the AKARI all-sky survey. Planck is scheduled for launch with Herschel in late 2008. We solved the so-called “submm Olbers’ Paradox” in our comprehensive study of submm local galaxy luminosity functions; this work has now been incorporated into the Planck sky model.

·         We are co-investigators in the proposed JAXA / ESA SPICA mission. SPICA is the next-generation mid-far-infrared space telescope, with a mid-infrared sensitivity far outstripping that of NASA’s proposed James Webb Space Telescope, and a far-infrared sensitivity far outstripping that of ESA’s Herschel. SPICA will has been approved for inclusion within ESA’s Cosmic Visions list of prospective missions.

·         The SCUBA-2 All Sky Survey. Serjeant led the development of the extragalactic programme for this major legacy survey on the James Clerk Maxwell Telescope and is now one of the survey's four co-ordinators. This survey will find the galaxies among the 2-3 most luminous in the observable Universe, test for the presence of cool local ultraluminous galaxies, find new gravitational lens systems, and constrain models of the most extreme star forming galaxies. This survey will commence in late 2008.

·         Serjeant serves as a co-ordinator for the JCMT Nearby Galaxies Survey, another major legacy survey on the James Clerk Maxwell Telescope, and Barnard is leading the X-ray follow-ups. This survey will map over a hundred nearby galaxies at high spatial resolution in the submm, and in the CO J=3-2 line, probing the physics of the dusty interstellar media. This survey started in November 2007.

·         We are members of the SCUBA-2 Cosmology Legacy Survey, another major legacy survey on the James Clerk Maxwell Telescope. The discovery of bright (mJy-level) submm-luminous galaxy populations has driven much recent progress in semi-analytical descriptions of galaxy evolution. This survey will make the definitive analysis of the clustering of submm galaxies, revolutionising our understanding of galaxy evolution in general, and will commence in late 2008. This survey is also covering the AKARI Deep Field at the North Ecliptic Pole, where photometric redshifts are available purely from the passage of redshifted PAH features through AKARI’s superlative multi-wavelength coverage.

·         Serjeant is a member of the Spitzer SWIRE Legacy Survey. SWIRE covers the same cosmological comoving volume as the Sloan Digital Sky Survey, but at redshift z around 1. Our breakthrough identifications of submm galaxies with the Spitzer Space Telescope’s early release observations were a milestone in the field.

·         We have recently completed the SCUBA Half Degree Extragalactic Survey (SHADES). This is a 70+ strong international collaboration, and we are in the process of analysing a supplementary survey of the same fields with the AzTEC camera. SHADES was the largest extragalactic submm survey to date, and aimed at estimating the clustering strength of submm galaxies and determining the predominance of black hole accretion in these violently star-forming galaxies.

·         We are members of the UKIDSS consortium and part of its Ultra Deep Survey. The principal goals of this survey are to discover the epoch of spheroid formation; to produce the first large-volume map of the high-redshift z=3 Universe; and to measure the growth of structure and bias since z=3.

·         Group members are involved in ESA’s proposed Darwin mission. Besides exoplanets and the search for exo-life, Darwin direct imaging will be a powerful tool to investigate the morphology of hot dust in starburst galaxies

·         Serjeant and White are co-Is on ESA’s proposed far-infrared interferometer mission FIRI which will produce sub-arcsecond angular resolution in the far-infrared, revolutionising far-infrared astronomy after its launch in 2025 or later.

·         We also have theoretical modelling and data analysis projects of the cosmic near-infrared background and associated foregrounds. This background is thought to be dominated by population III stars which first reionized the Universe, but the foregrounds from sunlight scattered by zodiacal dust dominate the signal, requiring careful modelling.