potw2302 — Picture of the Week
Closest pair of supermassive black holes as seen by MUSE
10 January 2023: In this Picture of the Week we peer closer into the galaxy UGC 4211, where astronomers have discovered two supermassive black holes on the verge of merging, separated by just 750 lightyears — the closest to have been found to date using multiple wavelengths and less than half of the previous record. They used ESO’s Very Large Telescope (VLT), the Atacama Large Millimeter/submillimeter Array (ALMA), of which ESO is a partner, and other telescopes to detect the bright light produced as the black holes engulf material in their vicinity. Both of the images shown here were made using data from the MUSE instrument on ESO’s VLT in Chile. The left image shows a classical view of this galaxy, with dust lanes obscuring starlight. The image on the right shows emission from oxygen, nitrogen and hydrogen in blue, green and red respectively. Red indicates areas of star formation, and the bright ...