PhD at Jodrell Bank Centre for Astrophysics

Supervisor: Dr. Clive Dickinson

The Cosmic Microwave Background (CMB), the relic radiation from the Big Bang era, is one of the most import cosmological tools available for studying the Universe. Much of our current understanding comes from the all-sky measurements made by NASA's Wilkinson Microwave Anisotropy Probe (WMAP). Given the unprecedented sensitivity of current CMB experiments, the major challenge is understanding and removal of the competing "foreground" signals from our Galaxy and extragalactic radio sources. The problem of foregrounds is particularly acute for measuring the polarisation of CMB, which is now the focus of several experiments. The main aim is to try to detect large-scale "B-modes", produced by gravitational waves in the early Universe, a firm prediction of a range of inflationary models. However, the amplitude of these B-modes is expected to be tiny (several orders of magnitude weaker than the primary temperature anisotropies), and could even be zero (if there was no inflation). Constraining the amplitude of this signal is one of the major goals of future CMB experiments, but it will require exquisite control of systematics, and in particular, accurate foreground removal and error propagation.

 The goal of this PhD is to improve our understanding of these foregrounds, and to develop tools to allow accurate component separation. JBCA is a world-leader in foreground research and is coordinating the Galactic science programme for the Planck mission. The student will gain experience of observations and data analysis, and will be involved in one or more CMB/foreground experiments that JBCA is involved in (C-BASS, Planck, QUIET, QUIJOTE, OCRA). The research will be of great value to the CMB and cosmological communities. The student will work on one or more of the following topics:-

1. Understand the physical mechanisms underlying radio & microwave from the Galaxy and extragalactic sources.
2. Test and produce new spatial templates for each emission component: synchrotron, free-free, thermal dust and anomalous dust components.
3. Observe and analyse radio data (including radio recombination lines from HIPASS and continuum data from e.g. CBI,OCRA-f,VLA, ATCA, GBT) to understand diffuse emission at high resolution.
4. Test and develop component separation algorithms for multi-frequency data sets.
5. Combine multi-frequency datasets (e.g. C-BASS, QUIET, QUIJOTE, Planck) and apply component separation to provide more precise CMB measurements.
6. Study frequency optimisation for a future CMB polarization satellites (e.g. B-Pol, CMBPol).
7. Apply new measurements of radio source counts to estimate the contamination of CMB .

The PhD studentship is financed by a European Commission grant to the P.I. (Dr. Clive Dickinson). There is a stipend of 17,010 GBP (tax-free) per year for 3 years. The student will be responsible for paying their own fees (currently 3390 GBP, as of Jan 2010, and 3500 GBP from Sept 2010 for UK/EU students). There is additional money for travel and computing. The money will be available from June 1st 2010. The PhD should start on, or as soon as possible after, June 1st 2010, but no later than 1st October. For more information, e-mail: Clive.Dickinson@manchester.ac.uk