The European VLBI Network (EVN) is a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa and Puerto Rico, which performs very high angular resolution observations of cosmic radio sources using very-long-baseline interferometry (VLBI). The EVN is the most sensitive VLBI array in the world, and the only one capable of real-time observations. The Joint Institute for VLBI ERIC (JIVE) acts as the central organisation in the EVN, providing both scientific user support and a correlator facility. Very Long Baseline Interferometry (VLBI) achieves ultra-high angular resolution and is a multi-disciplinary technique used in astronomy, geodesy and astrometry.
The EVN operates an open-sky policy, allowing anyone to propose an observation using the network
EVN Telescopes The EVN network comprises 22 telescope facilities:
Name Dish Size Location Operated by Effelsberg 100-m Radio Telescope 100 metres Effelsberg, Germany Max Planck Institute for Radio Astronomy Westerbork Synthesis Radio Telescope 12 x 25 metres Westerbork, Netherlands ASTRON Sardinia Radio Telescope 64 metres San Basilio, Italy Istituto Nazionale di Astrofisica Lovell Telescope 76 metres Goostrey, Cheshire, United Kingdom Jodrell Bank Observatory Cambridge 32 metres 32 metres Mullard Radio Astronomy Observatory, United Kingdom Jodrell Bank Observatory Mark II 25 metres Goostrey, Cheshire, United Kingdom Jodrell Bank Observatory Medicina Radio Observatory 32 metres Medicina, Italy Istituto Nazionale di Astrofisica Onsala Space Observatory 25 metres and 20 metres Onsala, Sweden Chalmers University of Technology Ventspils International Radio Astronomy Centre 32 metres and 16 metres Ventspils, Irbene, Latvia Ventspils University College Noto Radio Observatory 32 metres Noto, Italy Istituto Nazionale di Astrofisica Toruń Centre for Astronomy 32 metres Toruń, Poland Nicolaus Copernicus University Metsähovi Radio Observatory 14 metres Kirkkonummi, Finland Aalto University Sheshan 25 metres 25 metres Sheshan, Shanghai, China Shanghai Astronomical Observatory Nanshan 25 metres 25 metres Ürümqi, China Spanish National Observatory 40 metres and 14 metres Yebes, Guadalajara, Spain Instituto Geográfico Nacional (Spain) Wettzell (20m Radio telescope) 20 metres GermanyBundesamt für Kartographie und Geodäsie (BKG) and Technical University of Munich (TUM) Madrid Deep Space Communication Complex 70 metres 34 metres Robledo de Chavela, Spain INTA / NASA / JPL Hartebeesthoek Radio Astronomy Observatory 26 metres Hartebeesthoek, South Africa National Research Foundation of South Africa Arecibo Observatory 305 metres Arecibo, Puerto Rico SRI International / USRA / UMET RAO Svetloe 32 metres Leningrad, Russia Institute of Applied Astronomy RAO Zelenchuckskaya 32 metres Zelenchukskaya, Zelenchuksky, Karachay-Cherkessia, Russia Institute of Applied Astronomy RAO Badary 32 metres Badary, Tunkinsky, Buryatia, Russia Institute of Applied Astronomy
Additionally the EVN often links with the UK-based 7-element Jodrell Bank MERLIN interferometer. It can also be connected to the US Very Long Baseline Array (VLBA), achieving a global VLBI, obtaining sub-milliarcsecond resolution at frequencies higher than 5 GHz.
e-EVN Since 2004, the EVN has started to be linked together using international fibre optic networks, through a technique known as e-VLBI. The EXPReS project was designed to connect telescopes at Gigabit per second links via their National Research Networks and the Pan-European research network GÉANT2, and make the first astronomical experiments using this new technique. This allows researchers to take advantage of the e-EVN's Targets of Opportunity for conducting follow-on observations of transient events such as X-ray binary flares, supernova explosions and gamma-ray bursts.
EXPReS's objectives are to connect up to 16 of the world's most sensitive radio telescopes on six continents to the central data processor of the European VLBI Network at the Joint Institute for VLBI ERIC (JIVE). Specific activities involve securing "last-mile connections" and upgrading existing connections to the telescopes, updating the correlator to process up to 16 data streams at 1 Gbit/s each in real time and research possibilities for distributed computing to replace the centralized data processor.
History The EVN was formed in 1980 by a consortium of five of the major radio astronomy institutes in Europe (the European Consortium for VLBI). Since 1980, the EVN and the Consortium has grown to include many institutes with numerous radio telescopes in several western European countries as well as associated institutes with telescopes in Russia, Ukraine, China and South Africa. Proposals for an additional telescope in Spain are under consideration.
Observations using the EVN have contributed to scientific research on Fast Radio Bursts (FRBs), gravitational lensing, and supermassive black holes.
See also Northern Extended Millimeter Array
References
External links
The European VLBI Network on the internet Joint Institute for VLBI ERIC on the internet