Antenna technology and radio astronomical research — A perspective on the trends

摘要

“Classical” radio astronomy is flourishing - its capabilities continue to grow as new technologies are married with ever wider-ranging astrophysical ambitions. I will present a strategic overview of trends concentrating on frequencies within the ground based window. Progress is always made by exploring new regions of observational parameter space (spectral range & resolution; brightness sensitivity; angular coverage & resolution; temporal coverage and resolution) enabled by the application of new technology. The areas now undergoing most change are: i) a focus on low frequencies - from 10s of MHz to ~ 1 GHz; ii) brightness sensitivity; iii) survey speed; iv) exploitation of the time domain. To a significant extent these have been triggered by the science thinking and the R&D associated with the Square Kilometre Array. The SKA is far from the only major radio telescope development currently underway. Two large single dishes have recently been completed: the 64-m Sardinia Radio Telescope and the Five-hundred-metre Aperture Telescope; other large steerable dishes are being planned. Complementing them are new multi-purpose interferometric “precursors” to the SKA (e.g., LOFAR, ASKAP, MeerKat, MWA, LWA ) while a raft of more specialized instruments are underway including CHIME (in Canada); TIAN LAI (in China); BINGO (in Uruguay); HERA & HIRAX (in South Africa). There are, of course, many existing radio telescopes in active use around the world whose capabilities are continuously being enhanced by technology-based upgrades - pulsars and the time domain astrophysics being the obvious beneficiaries.