A team of scientists from the Ohio State University in Columbus were able to get more insights on a nearby starburst galaxy and early star formation by using Atacama Large Millimeter/submillimeter Array (ALMA), one of the world’s largest and most accurate radio telescopes.
Researchers focused their research on NGC 253, or the Sculptor Galaxy, which is located nearly 11.5 million light-years away. Due to its relatively close location, the galaxy was successfully mapped by ALMA, providing astronomers with additional info on stellar nurseries located at its core.
Starburst galaxies are much denser and 1,000 times faster in forming new stars than regular spiral galaxies, such as the Milky Way. ALMA analyzed layer by layer a cluster of stellar nurseries located into the heart of NGC 253.
To the scientists’ surprise, ALMA revealed that the cluster included 10 separate stellar nurseries, that couldn’t be detected with other telescopes. Adam Leroy, co-author of the findings and astronomer with the Ohio State University in Columbus, explained that all stars form in dense clouds of dust and gas, also known as stellar nurseries.
“Until now, however, scientists struggled to see exactly what was going on inside starburst galaxies that distinguished them from other star-forming regions,”
But ALMA helped scientists understand more what was going on within those star-forming regions. The telescope dissected layer by layer the core of NGC 253, a disk-shape galaxy marked by intense starbursts, and revealed that its stellar nurseries were ten times denser, more massive and a lot more restless than those in spiral galaxies.
Prof. Leroy argued that the starburst galaxies are plain better at forming new stars since their gas material is denser and better than in other galaxies. He also said that his team used ALMA on NGC 253 to understand why the gas in starburst galaxies was superior when involving star formation.
The scientists first noticed that there were ten different star-formation regions in the heart of the NGC 253. Soon afterward, they used ALMA to map the zone’s wavelength signatures from different gas molecules. They found clusters of carbon monoxide which matched envelops of less dense gas around star-formation regions; hydrogen cyanide clusters which matched medium dense areas of star formation; and rarer H13CN and H13CO+ molecules, which were corresponding to the most dense regions.
Researchers learned that a galaxy is better at forming stars than other galaxies not just by the larger number of the stellar nurseries, but also by the quality of these star-forming clouds. In a starburst galaxy, stellar nurseries pack much material in a much smaller space than those in regular galaxies, making them more proficient in stellar formation, scientists explained.
Image Source: Daily Galaxy