Astronomy:European VLBI Network

From HandWiki
Short description: Network of radio telescopes across Europe that link together for radio interferometry
European VLBI Network

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[1]

EVN Telescopes

The EVN network comprises 22 telescope facilities:[2]

Name Dish Size Location Operated by
Effelsberg 100-m Radio Telescope 100 metres Germany Effelsberg, Germany Max Planck Institute for Radio Astronomy
Westerbork Synthesis Radio Telescope 12 x 25 metres Netherlands Westerbork, Netherlands ASTRON
Sardinia Radio Telescope 64 metres Italy San Basilio, Italy Istituto Nazionale di Astrofisica
Lovell Telescope 76 metres United Kingdom Goostrey, Cheshire, United Kingdom Jodrell Bank Observatory
Cambridge 32 metres 32 metres United Kingdom Mullard Radio Astronomy Observatory, United Kingdom Jodrell Bank Observatory
Mark II 25 metres United Kingdom Goostrey, Cheshire, United Kingdom Jodrell Bank Observatory
Medicina Radio Observatory 32 metres Italy Medicina, Italy Istituto Nazionale di Astrofisica
Onsala Space Observatory 25 metres and 20 metres Sweden Onsala, Sweden Chalmers University of Technology
Ventspils International Radio Astronomy Centre 32 metres and 16 metres Latvia Ventspils, Irbene, Latvia Ventspils University College
Noto Radio Observatory 32 metres Italy Noto, Italy Istituto Nazionale di Astrofisica
Toruń Centre for Astronomy 32 metres Poland Toruń, Poland Nicolaus Copernicus University
Metsähovi Radio Observatory 14 metres Finland Kirkkonummi, Finland Aalto University
Sheshan 25 metres 25 metres China Sheshan, Shanghai, China Shanghai Astronomical Observatory
Nanshan 25 metres 25 metres China Ürümqi, China
Spanish National Observatory 40 metres and 14 metres Spain Yebes, Guadalajara, Spain Instituto Geográfico Nacional (Spain)
Wettzell (20m Radio telescope) 20 metres Germany Germany Bundesamt für Kartographie und Geodäsie (BKG) Technische Universität München (TUM)
Madrid Deep Space Communication Complex 70 metres

34 metres

Spain Robledo de Chavela, Spain INTA / NASA / JPL
Hartebeesthoek Radio Astronomy Observatory 26 metres South Africa Hartebeesthoek, South Africa National Research Foundation of South Africa
Arecibo Observatory 305 metres United States Arecibo, Puerto Rico SRI International / USRA / UMET
RAO Svetloe 32 metres Russia Leningrad, Russia Institute of Applied Astronomy
RAO Zelenchuckskaya 32 metres Russia Zelenchukskaya, Zelenchuksky, Karachay-Cherkessia, Russia Institute of Applied Astronomy
RAO Badary 32 metres Russia 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.[3]

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),[4] gravitational lensing,[5] and supermassive black holes.[6]

See also

References

External links