VLBI-40 collects the presentations that were given as talks or posters at the Bologna-VLBI conference on 2023 May 22-26 (https://vlbi-40.ira.inaf.it).
Thanks to recent technological advances, over the past few years Very Long Baseline Interferometry observations have achieved outstanding milestones in fields ranging from relativistic astrophysics to fundamental physics, with the imaging of the supermassive black holes at event horizon resolution, the formation of relativistic jets following a neutron star merger, the localisation of fast radio bursts, and more. These have been the results of huge technological progress on the VLBI instrumentation (receivers, backends, correlator facilities) and of a blossoming multi-messenger landscape.
The broadening of VLBI arrays operating from the few hundred MHz of LOFAR-VLBI, to the few hundred GHz of EHT – now allows unprecedented synergies among the existing facilities.
The current and forthcoming generation of ground and space observatories working across and beyond the electromagnetic spectrum are considerably expanding the role VLBI can play in the multi-messenger context. Particularly relevant are the synergies with ALMA, JWST, Gaia, ELT, and CTA, with neutrino (IceCube) and the new gravitational wave detectors, such as the Einstein Telescope, and between maser VLBI and sub-mm astrophysics.
In such a fertile environment, a number of scientific areas novel to VLBI, as for instance cosmology – through probes such as FRBs and gravitational lensing – and extreme transients, are promising major advances.
Last but not least, the radio astronomical future is sparkling, and VLBI will be crucial to complete the scientific discovery potential of the SKA and ngVLA.
The goal of this conference was to assess and discuss the present and future role of VLBI, with a focus on:
- the scientific relevance of VLBI in the light of the present framework of multi-messenger facilities and of the current VLBI capabilities in frequency, time and dynamic range domains;
- the potentials and the synergies between different VLBI arrays throughout the world;
- new developments in technology and methods;
- the future of VLBI beyond the present decade.
In addition to scientific and technological sessions, the conference included a session on the Global VLBI Alliance.