PhD Projects 2018

Next-generation radio telescopes
Mike Jones, Angela Taylor, Kris Zarb Adami, Jamie Leech

Over the next few years a new generation of radio telescopes will be built which will transform astrophysics and cosmology. Over the frequency range 50 MHz to 50 GHz, new telescopes will explore the deep Universe in the redshifted bands of hydrogen, as well as in radio continuum emission and the cosmic microwave background itself. We are working on a range of projects at different stages of development, and we are looking for students who are interested in working with data from these new instruments, either on the design and development of new technologies for future instruments, or on the commissioning and data analysis on instruments already in operation.

We are looking for students to work with us on several specific projects:

Commissioning and early science from the low-frequency aperture array of the SKA.
Mike Jones, Kris Zarb-Adami

SKA-Low will be a large-scale aperture array focussed on detection of the HI signature of the epoch of reionization (EoR) at redshift 6 - 12. Oxford is leading the design of the signal processing system for SKA-Low. A prototype of SKA-Low is being constructed on the SKA site in Western Australia - the Aperture Array Verification System 1. AAVS1 will be a significant radio telescope in its own right as well as an engineering prototype for the SKA, and it will be used to demonstrate the ability of the SKA to make deep images at low frequency across a very large bandwidth. The student would take part in the commissioning of the signal processing system and the array as a whole, and use the array to make the first science observations with SKA-Low hardware.

Advanced receiver development
Mike Jones, Angela Taylor,Jamie Leech

Improvements in radio receiver technology drive the advances in the science that we are able to do with telescopes such as the SKA. Oxford is leading a number of developments in radio receiver design that will enable future generations of science projects, and there are opportunities to work on a number of projects putting these new technologies in to practice. We are leading the development of a receiver system for a new national facility radio telescope in Mexico, the first centimetre-wave telescope in that country, and also applying SKA digital technology to signal processing system for the Large Millimetre Telescope, a 50-m telescope also in Mexico. We are also planning to deliver new high-frequency (8 - 16 GHz) receivers for the UK's national radio astronomy observatory, e-MERLIN, which will allow us to image the formation of planets from rock and pebble-sized objects around nearby young stars . All of these projects give opportunities for innovative design in radio-frequency and microwave electronics and high-speed digital signal processing, for commissioning new state-of-the-art scientific instrumentation, and getting first-light science from these new instruments.

Polarized foregrounds for measuring the cosmic microwave background
Mike Jones, Angela Taylor, Jamie Leech

Observations of the cosmic microwave background radiation (CMB) have transformed our understanding of the universe over the past twenty years. The next big milestones will be the release of polarization data from the Planck satellite and ground-based CMB B-mode experiments. These give the possibility of detecting the curl-like component of the polarization of the CMB (the 'B-mode'), which will directly probe the physics of Inflation. One of the biggest problems as the sensitivity of CMB experiments gets ever better is removing the effects of foreground radiation, particularly from our Galaxy. Oxford Astrophysics, in collaboration with Manchester, Caltech and SKA South Africa, has built a pair of all-sky survey telescopes to definitively measure the synchrotron emission from the Galaxy in intensity and polarization, to improve foreground subtraction and hence significantly improve the sensitivity of experiments such as Planck. This C-Band All-Sky Survey (C-BASS) will also provide new insights in to the Galactic magnetic field and the properties and emission mechanisms of the interstellar medium. C-BASS North, at Owens Valley Radio Observatory in California, has completed its observations, and C-BASS South, at the MeerKAT site in Western Cape, South Africa, is currently observing.

We are looking for DPhil students to join our team working on the analysis of C-BASS data and also to be involved in preparations for a follow-up experiment to C-BASS, called 'NextBASS', which will operate at higher frequencies (~10-30 GHz). The aim of the new experiment will be to probe the Galactic foregrounds at higher frequency and in particular to make a survey for spinning dust and in support of current and planned higher frequency B-mode CMB experiments. We are also collaborating on an Italian-led experiment called STRIP, a 40 GHz polarimeter array to be based in Tenerife. Depending on the specific interests of the student, they will have the opportunity to be involved in one or more of the following areas:

1) Combined analysis of C-BASS and Planck, WMAP and other CMB polarization data to provide accurate measurements of the CMB temperature and polarization spectra.
2) Using the C-BASS data for specific studies of the Galaxy, Galactic magnetic field and inter-stellar medium.
3) Simulations of the radio sky at 10-30GHz and forecasting the performance and science capabilities of the new instrument in conjunction with other CMB and foreground data sets, in particular the Japanese-led satellite experiment LiteBIRD.
4) Developing the hardware for a next-generation ground-based foregrounds experiment. This could include working on the optical design, cryogenic receivers, or high-speed digital backend hardware and firmware.

For more information please contact: Angela Taylor (act@astro.ox.ac.uk), Jamie Leech (jxl@astro.ox.ac.uk) or Mike Jones (mike@astro.ox.ac.uk)