Low-frequency radio astronomy is difficult as a result of astronomical radio sources are very faint. Low-frequency gentle additionally has an extended wavelength, which signifies that it’s laborious to seize radio photos with good decision. To beat these challenges, LOFAR makes use of an array of omnidirectional antennas. It has about 20,000 antennas clustered at 52 stations throughout Europe. Collectively they create a digital telescope greater than 1,000 kilometers throughout. With such numerous antennas, processing the information is extraordinarily advanced. Different radio telescopes additionally mix a number of indicators from an antenna array, however LOFAR operates at such low frequencies that Earth’s ionosphere can distort the indicators. It’s much like the best way seen gentle might be distorted when considered via ripples of water. So highly effective new software program needed to be developed to transform the radio information into photos of the sky.
Not too long ago, LOFAR launched the primary information on its Lengthy Baseline Array Sky Survey. They’ve solely mapped 4% of the northern sky thus far, however have already mapped 25,000 supermassive black holes. Whereas the universe is stuffed with radio sources, most low-frequency radio gentle comes from concentrated sources similar to black holes on the hearts of galaxies. LOFAR has a excessive sufficient decision that the black gap map seems to be like a starry night time, with every black gap as an remoted radio dot, as you’ll be able to see within the picture above.
It’s going to take a number of extra years for the crew to make a full map of the northern sky. When accomplished, the sky survey might assist us study not solely about black holes but additionally concerning the large-scale construction of the cosmos.
Reference: de Gasperin, F., et al. “The LOFAR LBA Sky Survey I. survey description and preliminary information launch.” arXiv preprint arXiv:2102.09238 (2021).