New Night Sky Map Reveals 3 Lakh Unknown Galaxies

Last Updated on April 15, 2019 by Bharat Saini

‘Hundreds of Thousands’ Unknown Galaxies, previously unknown, have been discovered with 15 Million More Forecast using LOFAR telescope that can detect light sources – optical instruments cannot see, in a new night sky map published on Tuesday 19 February 19. This discovery literally shed new light on some of the Universe’s deepest secrets, including the physics of black holes and how clusters of galaxies evolve.

Low-Frequency Array or LOFAR Telescope, completed in 2012 and operated by ASTRON in the Netherlands Institute for Radio Astronomy, is a network of radio antennas in the Netherlands, Germany, the UK, France, Sweden, Poland, Ireland and Italy, all connected by high-speed fibre optic cables. The signals of the combined 100,000+ antennas are then processed by supercomputers to effectively create a virtual radio telescope dish measuring 1900 kilometres in diameter.

Radio astronomy is the detection of radio waves emitted by celestial objects. The radio signals collected by the LOFAR telescope have travelled billions of light years before reaching Earth.

• LOFAR consists of a vast array of omnidirectional antennas using a new concept in which the signals from the separate antennas are not combined in real time as they are in most array antennas.
• Electronic signals from the antennas are digitized, transported to a central digital processor, and combined in software to emulate a conventional antenna.
• Project is based on an interferometric array of radio telescopes using about 20000 small antennas concentrated in at least 48 stations.
• Interferometry is a family of techniques in which waves, usually electromagnetic waves, are superimposed causing the phenomenon of interference in order to extract information
• LOFAR’s mission is to map the Universe at radio frequencies from ~10–240 MHz with greater resolution and greater sensitivity than previous surveys, such as the 7C and 8C surveys, and surveys by the Very Large Array (VLA) and Giant Meter-wave Radio Telescope (GMRT).
• Data on just 2% of the night sky has revealed hundreds of thousands of previously undetected galaxies.
• It’s the first result from a major new radio sky survey of the night sky by LOFAR.
• Data comes from a survey of 25% of the northern hemisphere’s night sky at low radio frequencies, which revealed three hundred thousand sources, almost all of which are galaxies in the distant Universe.
• Astronomers behind the discovery ultimately expect to discover 15 million more radio sources after their survey of the entire northern hemisphere night sky is complete.
• Many of those sources are likely to be as-yet-undiscovered galaxies.