Free Astronomy Magazine September-October 2021

40 SEPTEMBER-OCTOBER 2021 ASTRO PUBLISHING VLT and ALMA reveal stunning features of nearby galaxies by ESO - Bárbara Ferreira A stronomers know that stars are born in clouds of gas, but what sets off star forma- tion, and how galaxies as a whole play into it, remains a mystery. To understand this process, a team of re- searchers has observed var- ious nearby galaxies with powerful telescopes on the ground and in space, scan- ning the different galactic regions involved in stellar births. “For the first time we are resolving individual units of star formation over a wide range of loca- tions and environments in a sample that well repre- sents the different types of galaxies,” says Eric Em- sellem, an astronomer at ESO in Germany and lead of the VLT-based observa- tions conducted as part of the Physics at High Angular resolution in Nearby Gal- axieS (PHANGS) project. “We can directly observe the gas that gives birth to stars, we see the young stars themselves, and we witness their evolution through var- ious phases.” I mage of the nearby galaxy NGC 4303 obtained by combining observations taken by the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT) and the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner. NGC 4303 is a spiral galaxy, centered on a bar of stars and gas, located approximately 55 million light-years from Earth in the constellation Virgo. [ESO/ALMA (ESO/NAOJ/NRAO)/PHANGS]