World’s largest telescope eyes up black hole
The International LOFAR Telescope - a network of radio telescopes across Europe - has taken its first ‘pictures’, revealing a black hole in a distant galaxy in greater detail than ever before. The image of the black hole, called quasar 3C196, also demonstrates the huge field of view that LOFAR captures in a single image: an area of sky equivalent to a thousand full moons.
LOFAR’s network of radio telescopes is designed to study the sky at unprecedented resolution, using the lowest radio frequencies accessible from the surface of the Earth. The UK LOFAR station, located at STFC's Chilbolton Observatory, is the western-most telescope in the network, and its addition creates a total array almost 1000 km wide, making LOFAR the largest telescope in the world. The addition of Chilbolton also makes LOFAR's images three times sharper.
Dr Philip Best, a Reader at the University’s Institute for Astronomy, is Deputy LOFAR-UK leader. He said: “LOFAR allows us to see smaller and fainter objects in the sky, which will help us to answer fundamental questions about cosmology and astrophysics, such as when did the first galaxies form. Here in Edinburgh we are very excited about using LOFAR to study galaxies and quasars in the early Universe."
The new image was created by combining signals from LOFAR radio telescopes in the Netherlands, France, Germany and the UK, using the LOFAR BlueGene/P supercomputer in the Netherlands. The connection between the Chilbolton
telescope and the supercomputer requires an internet speed of 10 gigabits per second – over 1000 faster than the typical home broadband speeds.
Professor Rob Fender, LOFAR-UK Leader from the University of Southampton, said "Getting that connection working without a hitch was a great feat requiring close collaboration between STFC, industry, universities around the country and our international colleagues.”
LOFAR was designed and built by ASTRON in the Netherlands and is currently being extended across Europe. As well as deep cosmology, LOFAR will be used to monitor the Sun’s activity, study planets, and understand more about lightning and geomagnetic storms. LOFAR will also contribute to UK and European preparations for the planned global next generation radio telescope, the Square Kilometre Array (SKA).
LOFAR will focus on six areas of research:
- 1.The Epoch of Reionisation - understanding how the first stars and black holes made the universe hot.
- 2.Extragalactic surveys - what is the history of star formation and black hole growth over cosmological time?
- 3.Transients and Pulsars - probing the extreme astrophysical environments that lead to transient bright bursts in the radio sky.
- 4.Cosmic rays - what is the origin of the most energetic particles in the universe?
- 5.Solar and space environment - mapping the structure of the solar wind, how it relates to solar bursts, and how it interacts with the Earth.
- 6.Cosmic Magnetism - what is the origin of the large-scale magnetic fields that pervade the universe?
The LOFAR station in the UK is the first major new radio telescope to be built in Britain for many decades and was opened by Professor Jocelyn Bell-Burnell on the 20th September 2010. Like all the other stations, it is linked back to a central supercomputing facility at Groningen in the Netherlands using a high-speed network connection, the equivalent of 5000 standard domestic broadband connections combined into one.
LOFAR-UK is funded through a collaboration of UK universities with the SEPnet consortium and the UK Science and Technologies Facilities Council which includes RAL Space at STFC's Rutherford Appleton Laboratory, STFC's UK Astronomy Technology Centre and STFC's Chilbolton Observatory.The LOFAR-UK consortium represents 22 British universities, making it the largest radio astronomy consortium in the country.
The quasar galaxy 3C 196
3C 196 is a quasar (compact radio source) in a galaxy so far away that light from it has travelled for almost half the age of the universe to reach us (at a redshift of z=0.871). The word “quasar” means “quasi-stellar object”. Quasars look like single stars in visible light because the light coming from close to the central black hole is so bright that it outshines all the stars in the galaxy in which it is embedded. The quasar 3C 196 was picked for the first light image of the LOFAR Telescope to show the massive increase in image sharpness (resolution) when the international stations are added to LOFAR.