The GVA Science Forum (GVAS) evaluates and fosters the unique and complementary contribution of VLBI to astrophysical research. Members are active scientists, not necessarily linked to any of the VLBI networks in the GVA.
The GVAS provides the opportunity for scientists to identify needs and engage in discussions on how to keep the VLBI facilities responding to the latest astronomical challenges, participating and providing input to roadmap exercises. Recent examples are the excellent review of VLBI in the EVN science vision 2020-2030 document , “VLBI20-30: a scientific roadmap for the next decade – The future of the European VLBI Network”, to optimise its unique role in the context of a rapidly evolving set of global astronomical facilities as planned for the next few decades. In the USA, the NSF Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020)  aims to support NSF to fund design and cost studies and prototyping for the next-generation Very Large Array (ngVLA), a potential replacement for the Jansky Very Large Array and the Very Long Baseline Array radio astronomy facilities.
The scientists involved can evaluate not only the synergies between VLBI facilities, but also exploit the unique and complementary characteristics that enhance the contribution of VLBI to astrophysical research, such as different frequency coverage, angular resolution, sensitivity, availability for studies that require observations with different cadences, real time capabilities, access to different regions of the sky, etc. Moreover, incorporate the VLBI aspect to roadmap exercises such as the Astronet Science Vision and Infrastructure Roadmap for European Astronomy , facilitating the coordination of VLBI networks with other astronomical instruments.
The GVAS is also a forum for cross-fertilisation where scientists habitual users of some regional VLBI network can meet with other colleagues and start global collaborations, in line with the true international nature of VLBI.
IAU Commission B4 WG on “Global VLBI Alliance”:
Links to Science Visions:
- T. Venturi, M. Lindqvist, Z. Paragi et al., VLBI20-30: a scientific roadmap for the next decade – The future of the European VLBI Network, arXiv:2007.02347 (2020): https://arxiv.org/abs/2007.02347
- USA NSF Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020): https://nap.edu/resource/26141/interactive/ and https://www.aip.org/fyi/2021/astro2020-decadal-survey-arrives-priorities-major-facilities
- Astronet Science Vision and Infrastructure Roadmap for European Astronomy (2021): https://www.astronet-eu.org/forums/roadmap-community-consultation
Access to the VLBI networks in the GVA:
- EVN+eMERLIN: https://www.evlbi.org/using-evn
- eMERLIN (standalone): http://www.e-merlin.ac.uk/observe.html
- NRAO VLBA: https://science.nrao.edu/facilities/vlba/docs/manuals/obsvlba/referencemanual-all-pages
- EAVN: https://radio.kasi.re.kr/proposal/cfp.php?site=eavn
- KVN (standalone): https://radio.kasi.re.kr/kvn/main_kvn.php
- VERA (standalone): https://www.miz.nao.ac.jp/veraserver/
- Southern Hemisphere LBA: https://www.atnf.csiro.au/vlbi/overview/index.html