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Arecibo Joins Global Network to Create 6,800-mile Diameter Radio Telescope

06/15/2008 02:11PM

Arecibo Joins Global Network to Create 6,800-mile Diameter Radio Telescope
Arecibo Observatory in Puerto Rico joined other telescopes in North America, South America, Europe and Africa in simultaneously observing the same targets, simulating a telescope more than 6,800 miles (almost 11,000 kilometers) in diameter.

The telescopes are all members of the Express Production Real-time eVLBI Service (EXPReS) project, and May 22, 2008 marked a live demonstration of their first four-continent, real-time, electronic Very Long Baseline Interferometry (eVLBI) observations.

VLBI uses multiple radio telescopes to simultaneously observe the same region of sky -- essentially creating a giant instrument as big as the separation of the dishes. VLBI can generate images of cosmic radio sources with up to 100 times better resolution than images from the best optical telescopes.

The Arecibo team called the demonstration a major milestone in the telescope's eVLBI participation, with a data-streaming rate to the central signal processor at the Joint Institute for VLBI in Europe (JIVE) in the Netherlands four times higher than Arecibo had previously achieved.

"These results are very significant for the advance of radio astronomy," said JIVE director Huib Jan van Langevelde. "It shows not only that telescopes of the future can be developed in worldwide collaboration, but that they can also be operated as truly global instruments."

EXPReS, funded by the European Commission, aims to connect up to 16 of the world's most sensitive radio telescopes to the JIVE processor to correlate VLBI data in real time. eVLBI is a technique by which remotely located radio telescopes observe the same region of sky simultaneously, and data from each telescope are sampled and sent to a central processor in real-time via high-speed communication networks.

This central data processor, a purpose-built supercomputer, decodes, aligns and correlates the
data for every possible pair of telescopes and can generate images of cosmic radio sources with up to a hundred times better resolution than images from the best optical telescopes.

This replaces the traditional VLBI method of shipping data on disk and provides astronomers with observational data in a matter of hours rather than weeks, allowing them to respond rapidly to transient events with follow-up observations. Through the elimination of the long delay between observations, correlation and subsequent data reduction, electronic realtime
VLBI enables astronomers to respond rapidly to so-called transient phenomena, like supernova explosions and gamma ray bursts. The development of e-VLBI also holds the potential for deeper and more sensitive observations by taking advantage
of the explosive growth of internet bandwidth, and will ensure that the European VLBI Network will remain both competitive and complementary to next-generation astronomical observatories.

The observation of 3C454.3 and other targets included four telescopes new to eVLBI capabilities of the European VLBI Network (EVN): Arecibo (Puerto Rico), Effelsberg (Germany), Hartebeesthoek (South Africa) and the Transportable Integrated Geodetic Observatory (TIGO, Chile).

They were joined in this observation by regular e-EVN participants Medicina (Italy), Onsala (Sweden) and Westerbork (the Netherlands). The observation is believed to have used one of the longest baselines ever for eVLBI. The TIGO to Onsala baseline measures 10,893 km, second only to an observation also conducted by EXPReS involving telescopes in Australia and Europe in August 2007.


For more information:

http://www.news.cornell.edu/stories/June08/arecibo.vlbi.html

http://www.nsf.gov/news/news_summ.jsp?cntn_id=111699&org=NSF&from=newsField

http://www.expres-eu.org/TERENA08_science.html

http://www.astromart.com/news/news.asp?news_id=827

http://www.astromart.com/news/news.asp?news_id=688

http://www.evlbi.org/

http://www.jive.nl/


Astromart News Archive:

http://www.astromart.com/news/search.asp?search=.+&search_btn=Go