Applications are invited for a Postdoctoral Research Assistant in Very High Angular Resolution Astrophysics at the Physics Department, University of Oxford. This project is an integral part of the Blackholistic collaboration, which is funded by an ERC Synergy grant and aims to try and unify accretion and jet formation across the black hole mass range. The collaboration incorporates observations, analytic and numerical modelling, as well as the development and construction of a new mm facility, The Africa Millimetre Telescope, in Namibia. The successful applicant will be based in Oxford and work on proposing for, and analysing, data with VLBI arrays to study relativistic jets from black holes. They will work with other observers and theoreticians to develop our understanding of black hole jet formation. They will work with a much larger group, including theoreticians, to understand those data. They are also expected to work on extending observations to higher-frequency, or newly-developed, VLBI arrays. You should hold a PhD (or close to completion) in astrophysics or a related field. Experience of radio VLBI and astrophysical jets is essential as well as experience in the field of relativistic jets and accreting black holes, in particular X-ray binaries, will be an advantage. Candidates are expected to demonstrate good communication skills and to be suited to working in a large team. Please direct enquiries about the role to Prof. Rob Fender ( Rob.Fender@physics.ox.ac.uk ). This is a full-time post, fixed term for 3 years The closing date for applications is noon UK time on Friday, 7 November 2025 You will be required to upload a CV (maximum three pages, including a publication list or a NASA ADS link) and a 2-page supporting statement of research interests and experience. The supporting statement must explain how you meet each of the selection criteria for the post using examples of your skills and experience. You should arrange for your 2 referees to send your reference to leanne.odonnell@physics.ox.ac.uk before the closing date.