DIRDI was delighted to host Members and Fellows for a presentation by Professor Leah Morabito FDIRDI on 6th November 2024. The talk, entitled ‘High-Resolution Imaging at the Lowest Frequencies: Technical Advances Driving Science’, provided an in-depth exploration of Leah’s recent work in astronomical imaging.
We welcomed a number of academics from the Departments of Physics, Engineering, and Mathematics, as well as several keen undergraduates in a relaxed session accompanied by a buffet lunch. Leah’s talk on her work developing new methods to image distant galaxies drew on expertise across the scientific disciplines and provoked some interesting questions from the very interdisciplinary audience. The presentation included an overview of the challenges of high-resolution imaging at low frequencies, how Leah’s groups calibration strategy overcomes these challenges, and a summary of recent results with a look towards future work.
Leah’s telescope array, the LOw Frequency ARray (LOFAR), has baselines up to 2,000 km, making it capable of achieving sub-arcsecond resolution at frequencies below 200 MHz, which can drive many science cases. However, high-resolution imaging at low frequencies is technically and logistically challenging: LOFAR’s phased-array design, the ionosphere, the lack of suitable calibrator information, and existing software tools all conspire to make it difficult to achieve the highest possible resolution at MHz frequencies.
Over the past few years, Leah’s collaborators have built on their growing understanding of these challenges to design a suitable calibration strategy, which is now implemented in a publicly available pipeline. In the past year this has enabled them to more than double the number of scientific papers published using sub-arcsecond imaging <200 MHz, including cutting-edge work to image the entire 5 square degree field of view of LOFAR at sub-arcsecond resolution.
We are grateful to Leah for giving such an insightful and accessible talk and to Hatfield College and Professor Ann Maclarnon for hosting the event.
