A new study reveals how stars that are formed into massive groups of globular clusters are conducive for producing new generation of stars as these can suck in stellar fuel from a nearby galaxy.
New findings are based on these observations from globular star clusters located in the Large and Small Magellanic Clouds that are also two of Milky Way's neighboring galaxies. According to co-author of the study, Aaron M. Geller of Northwestern University, these globular stellar clusters are apparently more complex than first thought.
This new study suggests that star clusters can now form new stars as these stars can attract gases from their environment which is a new idea. They are also described as dazzling swarms packed with millions of stars that have been tightly bound together since the early days of the universe, due to gravitational forces, forming stellar spheres at the edges of galaxies.
Astronomers also believe that the stars inside these globular clusters are the same age with each other. However, there are also older globular clusters of stars that are estimated to be more than 10 billion years old, that possess a population of younger stars, which suggests that a single star forming phenomenon might have transpired at a certain time.
What occurs inside these globular star clusters are powerful supernovae explosions when massive stars die, that can blast off any remaining star making material, depriving them of stellar formations. According to Geller, stars with higher masses die young as they transform into supernovae.
He explains how a supernova explosion can expel all its outer layers, which can also expel all the surrounding gas inside the cluster. This can exhaust all stellar fuel after about 70 million years until there are no gases left to make new stars.
However, new stars are still forming inside these globular clusters. In this new study, the team utilized data from the Hubble Space Telescope to investigate two star clusters known as NGC 1783 and NGC 1696 that are located inside the Magellanic Cloud and cluster NGC 411 in the Smaller Magellanic Cloud.
Astronomers have determined their age by observing their brightness and colors. The clusters were around 1 to 2 billion years old, containing stars that are millions of years younger than the original stellar population, which means bursts of star formations have taken place in separate events.
The team concluded that the clusters were able to suck in star forming material from their host galaxy's gas disks during their first stages of formation and during more recent bursts of star generation, contradicting other theories how older stars in the clusters have shed enough gas during rounds of star birth or additional star births are only caused by colliding stars and gas accretion from nearby stars.
This new study is published in the journal Nature.