Astronomers have used computer simulations based on theoretical models to explain massive star formation observed in dwarf galaxies. Researchers in the US and the Netherlands found that during a dark matter satellite’s closest approach to a dwarf galaxy, through gravity it compresses the gas in the dwarf, triggering significant episodes of starbursts.
In general, the larger a galaxy’s mass, the higher its rate of forming new stars. However, every now and then a galaxy will display a burst of newly-formed stars that shine brighter than the rest. Researchers using the Atacama Large Millimetre Array (ALMA) have found that galaxies forming stars at extreme rates 9 billion years ago were more efficient than average galaxies today.
Starburst galaxies transmute gas into new stars up to 1,000 times faster than typical spiral galaxies like the Milky Way. To try and understand why, an international team of astronomers used the Atacama Large Millimeter/submillimetre Array (ALMA) to dissect a cluster of star-forming clouds at the heart of NGC 253 — one of the nearest starburst galaxies.