Light and dust play a crucial role in the formation of life in galaxies: Study

A new study led by Australian National University researchers takes a closer look at a cosmic phenomenon that slows down the energy-intensive process of star formation to pave the way for life in a galaxy. The team studied the process whereby stars provide a counter-pressure to gravity that slows down the process of star formation, Dr Roland Crocker, lead researcher from the ANU Research School of Astronomy and Astrophysics, told university press. “If star formation happened rapidly, all stars would be bound together in massive clusters… where the intense radiation and supernova explosions would likely sterilise all the planetary systems, preventing the emergence of life,” Crocker said. “The conditions in these massive star clusters may even prevent planets from forming in the first place.” The researchers discovered that the majority of the process is influenced by light in different forms of energy. Ultraviolet light and visible light from large, newborn stars hit residual cosmic dust in the space surrounding a newly-formed star. [caption id=“attachment_5357411” align=“alignnone” width=“1280”] M78 Spiral Galaxy, like many others that have been used in studying the age of the universe, are a strong source of radiowaves. Image courtesy: NASA/Hubble[/caption] Infrared light is also scattered by this remnant cosmic dust, which energizes the air surrounding the newborn star, and acts like a counter-pressure to the gravitational force of the star. “The phenomenon we studied occurs in galaxies and star clusters where there’s a lot of dusty gas that is forming heaps of stars relatively quickly," Crocker said. “In galaxies forming stars more slowly—such as the Milky Way—other processes are slowing things down. The Milky Way forms two new stars every year, on average." Astronomers accept that all galaxies in the universe form new stars continuously and at a steady rate. The new study found a mathematical upper limit on how quickly stars can form in a galaxy or gas giant cloud. The counter-pressure and capacity of star formation in galaxies are some of the feedback mechanisms that star systems have to keep the universe alive and vibrant, according to Crocker. “We are investigating other ways stars might feedback into their environment to slow down the overall rate of star formation.” The study was published in the journal Monthly Notices of the Royal Astronomical Society.