Starburst Galaxies send gas into new stars at a dizzying pace which could be 1000 times quicker than typical spiral galaxies like our Milky Way. To understand why some Galaxies burst while the others do not, a team of international astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe a cluster of star forming clouds located at the heart of NGC 253 which is one of the nearest starburst galaxies near the Milky Way.
What are the requirements of starburst? Astronomers used ALMA to study NGC 253 and the new ALMA data reveal a diffuse cover of carbon monoxide gas and it surrounds stellar nurseries which are regions of active star formation. Studying these regions with ALMA data astronomers are trying to unravel the processes and conditions that drive furious star formation.
Adam Leroy, an astronomer formerly with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and now with The Ohio State University in Columbus said, “All stars form in dense clouds of dust and gas. Until now, however, scientists struggled to see exactly what was going on inside starburst galaxies that distinguished them from other star-forming regions.”
ALMA is path breaking development and it offers the ability to resolve individual star-forming structures, even in distant systems. Using this capability Leroy and his colleagues mapped the spread and movements of multiple molecules in clouds at the core of NGC 253, also known as the Sculptor Galaxy
Sculptor is essentially a disk shaped galaxy and is in the throes of an intense starburst. It is approximately 11.5 million light years from Earth and its proximity makes Sculptor a tantalizing target for detailed study.
Leroy noted, “There is a class of galaxies and parts of galaxies, we call them starbursts, where we know that gas is just plain better at forming stars. To understand why, we took one of the nearest such regions and pulled it apart – layer by layer – to see what makes the gas in these places so much more efficient at star formation.”
ALMA’s extraordinary resolution and sensitivity enabled researchers to know exactly what is happening in the heart of the sculptor, something which was not possible with other earlier telescopes.