New Map of the Sky Published
LOFAR is an enormous European network of radio telescopes, which are connected to each other via a high-speed fibre-optic network and whose measuring signals are combined into a single signal. High-performance supercomputers convert 100,000 individual antennae into a virtual antenna dish with a diameter of 1,900 km. LOFAR operates in previously largely unexplored frequency ranges of approximately 10–80 MHz and 110–240 MHz. It is headed by the ASTRON research institution in the Netherlands and is considered to be the world’s leading telescope of its kind. There are six measurement stations in Germany, which are operated by different scientific institutions. One of these is located to the southeast of the campus of Forschungszentrum Jülich and is run by JSC together with the University of Bochum.
LOFAR produces enormous amounts of data, which need to be transferred, stored, and analysed. JSC is one of the three data centres in the project and is home to roughly 15 petabytes of data. This is almost half of all the LOFAR data, one of the largest astronomical data collections in the world. The data are stored in a distributed storage system based on dCache software. Processing these gigantic data sets is a great challenge. While positioned in the middle of a multi 10 GBit/s star-network topology, JSC furthermore coordinates the German LOFAR network activities for the observation data as well as the LOFAR archive data through modern JSC-operated DWDM (dense wavelength division multiplexing) connections. Over the last few years, the LOFAR data have become by far the biggest fraction of community-data transferred via the JSC-managed networks in and out of Forschungszentrum Jülich.
An international team of more than 200 astronomers from 18 countries recently published the first map produced by a radio sky survey with previously unprecedented sensitivity using the LOFAR radio telescope. The map reveals hundreds of thousands of unknown galaxies and sheds new light on research fields such as black holes, interstellar magnetic fields, and galaxy clusters. A special issue of the scientific journal Astronomy & Astrophysics is dedicated to the first 26 articles describing the results.
The creation of radio sky maps at low frequencies demands both considerable telescope and computation time as well as large teams to analyse the data. What would have taken centuries on conventional computers was achieved within one year thanks to the use of innovative algorithms and extremely powerful computers. Part of this work was done at JSC, where huge amounts of data were transformed into high-quality images, making use of JURECA and later of JUWELS.
Contact: Cristina Manzano, firstname.lastname@example.org
from JSC News No. 264, 27 March 2019