LOFAR
LOFAR ( abbreviation for Low Frequency Array ) is a radio interferometer, ie an assembly of many radio telescopes whose signals are combined into a single signal. In order to better reach and an angular resolution of one arc second with LOFAR, an expansion of the size of the Netherlands is not enough, therefore it was decided to spread LOFAR stations extend over the entire European continent. The telescope, at the time of its inauguration by the Dutch Queen Beatrix on 12 June 2010 in Europe around 10,000 individual antennas. The detectable frequency ranges include 10-80 MHz and 110-240 MHz.
LOFAR is a joint project of the Dutch astronomical organization ASTRON, the Universities of Amsterdam, Groningen, Leiden and Nijmegen and German participation consisting of twelve institutions that have joined together in the Long Wavelength Consortium ( GLOW ). Its members are the Leibniz Institute for Astrophysics Potsdam (AIP ) with the OSRA, the Max Planck Institute for Radio Astronomy ( MPIfR) in Bonn, the Max - Planck - Institute for Astrophysics ( MPA ) in Garching, the Excellence Cluster Universe Munich / Garching, the Thuringian state Observatory in Tautenburg, the Jacobs University Bremen and the universities of Bielefeld, Bochum, Bonn, Hamburg and Cologne.
The stations, each consisting of 192 individual antennas are located at different locations in the Netherlands, Germany and other European countries (France, UK, Sweden). Other stations in Poland, Ireland and Finland are planned. In the case of LOFAR are the individual antennas very simply constructed wire pyramids and less than a man - in contrast to previous interferometers such as the Very Large Array and the VLBI, in which the individual components are large parabolic antennas.
The low cost of antennas, making it possible to provide a large number of them. The collecting area of the complete network today is about 0.5 square kilometers at a stretch of more than 1,000 kilometers. The first Dutch prototype station worked Exloo 2006 in the province of Drenthe. By late 2012, 33 stations were taken in the Netherlands in operation; When completed, with 40 stations is to be achieved in the spring of 2013. This largest radio telescope in the world, to deliver shortly after the Big Bang, the wide views into space and insights from the time, has been inaugurated in June 2010. The first German station was commissioned in November 2007, in addition to the 100-m Effelsberg radio telescope in operation. Four other stations in Unterweilenbach / Garching, Tautenburg ( Thuringia), in Bornim at Potsdam and in Jülich followed until 2011. Depending on one station was in the UK ( Chilbolton ), in France on the grounds of the Nançay radio telescope and Sweden ( Onsala ) built. The regular observations began in December 2012.
The main factor that will determine the performance of the system is a central computer ( IBM Blue Gene supercomputer ) in the computer center of the University of Groningen (Netherlands ), which offset the individual signals of different antennas together and a very fast data communication network (Wide Area Network - WAN ). For the first German station in Effelsberg own fiber optic cable with a 10 Gigabit / s to the Max Planck Institute for Radio Astronomy in Bonn was laid. From there, the data on the German research network DFN to the Research Centre Jülich and on about the Dutch SURFnet to the central mainframe Blue Gene / P are conducted at the University of Groningen, which has a capacity of 37 teraflops.
The scientific goals of LOFAR were developed in six key international science projects, which are led by Dutch, German and British institutions. It is to be sought from the period around 1 billion years after the Big Bang at frequencies between 120 and 200 MHz for signals from the Reionisierungsepoche. Catalogs of radio sources at five frequencies to be created. Other objects are pulsars and radio signals from cosmic ray particles that penetrate Earth's atmosphere. The Max Planck Institute for Radio Astronomy in Bonn initiates " Key Science " project for the study of cosmic magnetic fields. The Leibniz Institute for Astrophysics Potsdam has taken to measure the radio emission from the sun the line of the Key Science project.
In addition to physical findings on galaxies, quasars, and the matter from the earliest days of the universe, the operators promise insights, should be designed in such a future, more powerful Internet. In addition, LOFAR telescope is a precursor of the planned Square Kilometre Array, a radio telescope with a collecting area square kilometers, which is built in 2017 as a worldwide community program in Australia and South Africa and work from 2020 of about 70 MHz to at least 10 GHz.
The array is to be used in the Netherlands for other purposes. For example, the units could be equipped with wind sensors to meet very precise wind forecasts with the obtained data. This is for example for wind farms is important. Seismic sensors may further be connected to the antenna, so that accurate measurements of seismic activity are possible.