Europe creates largest radio telescope network

One of the world's largest fully steerable telescopes is the 100-metre Effelsberg telescope, which recently joined e-EVN, Europe's largest radio interferometric telescope network. The new addition has enabled the network to double its surface and sensitivity. Many of us are a...

One of the world's largest fully steerable telescopes is the 100-metre Effelsberg telescope, which recently joined e-EVN, Europe's largest radio interferometric telescope network. The new addition has enabled the network to double its surface and sensitivity.

Many of us are already familiar with the large optical telescopes used by astronomers to explore the night sky. But these are not the only tools available for stargazing. Radio telescopes are also used to study naturally-occurring radio emissions from stars, galaxies, quasars, and other astronomical objects.

Effelsberg, which is operated by Max Planck Institute for Radio Astronomy, in Bonn Germany, connects to six other radio telescopes located across Europe that make up the e-EVN network. This is achieved using a 35 kilometre optical fibre link, the construction of which was partly funded by the Express Production Real-time e-VLBI Service (EXPReS) project of the European Commission.

With the entry of the Effelsberg into the network, the e-EVN project has become the fastest interferometric network in the world. To include it, the scientists conducted the first real-time electronic Very Long Baseline Interferometry (e-VLBI) observation. This involved electronically transferring data from Effelsberg to a super computer located at the Joint Institute for Very Long Baseline Interferometry (JIVE), in Dwingeloo, the Netherlands.

The data transfer was able to sustain a phenomenal speed of approximately 1 Gigabit (Gbps), which is over 500 times faster than regular private DSL connections. The e-VLBI observation also included data from the six remaining telescopes and resulted in a record-breaking total throughput of 6.71 Gbps from all seven stations.

In addition to increasing its speed, the arrival of Effelsberg has also helped the network enhance its sensitivity to detect extremely faint radio objects in the sky. It is estimated that one run at the data rate recorded by the e-VLBI observation collects 1.5 terabytes of data. With this, the network can produce the sharpest images in astronomy, with resolutions 100 times better than those of the Hubble Space Telescope.

'With the support of the Max Planck Society and the EU-funded EXPReS program, we are now, through the participation of the Effelsberg telescope, able to vastly expand the sensitivity of the nascent eVLBI service to a level that makes real astronomical studies with high resolution of short-term variable objects possible,' says Professor Anton Zensus, Director at the Max Planck Institute for Radio Astronomy in Bonn and Chair of the JIVE.

The other telescopes that participate in the network are located in Cambridge and Jodrell Bank (UK), Medicina (Italy), Onsala (Sweden), Torun (Poland) and Westerbork (the Netherlands).