An international team of astronomers has published a new map of the sky and inside that map are more than 25,000 supermassive black holes. The map is the most detailed celestial map in the low radio frequency range. It was built by astronomers using 52 stations with LOFAR antennas across nine European countries.
One look at the image above, which is a small screenshot of the sky survey map, and all the little dots look like stars. Scientists note All points are supermassive black holes, as each black hole is located in a different, distant galaxy. The radio emissions captured by antennas spread across Europe are emitted by the ejected material as it approaches a black hole. The researchers say the map was the result of many years of hard work using “very difficult data”.
The team had to devise ways to convert radio signals into images of the sky. The compilation of the sky map required scientists to combine 256 hours of observations of the northern sky. Supercomputers running new algorithms correcting the effects of the ionosphere had to work every four seconds. Despite the sheer number of supermassive black holes in this image, the map covers only four percent of the northern half of the sky.
The astronomers on the research team say they will continue mapping the sky until the entire northern sky is complete. The researchers say the map also gives insights into the large-scale structures of the universe along with other information.
The researchers haven’t indicated how long it would take to complete the entire sky map. One of the biggest challenges in mapping was that observations at longer radio wavelengths were difficult due to the Earth’s ionosphere. The team describes the ionosphere as a cloudy lens that is constantly moving across the radio telescope.