New Delhi: Astronomers have used the James Webb Space Telescope as well as the Hubble Space Telescope to determine that the more massive star clusters
disperse their natal gas clouds significantly faster than less massive ones. Star clusters are born around the same time from stellar nurseries, or vast clouds of gas and dust. The massive, newborn stars flood their host galaxies with ultraviolet radiation within about five million years, dissipating the remaining raw material and preventing the formation of new stars. The discovery is based on observations of nearly 9,000 young star clusters spread across four nearby galaxies.
The research provides new constraints on stellar feedback and its role in regulating star formation in galaxies. The international team analysed data from the FEAST programme targeting nearby galaxies. Webb’s infrared gaze can peer through the obscuring gas, while Hubble’s optical imaging allowed researchers to classify clusters ad different evolutionary stages. The masses and ages were estimated based on the spectra. Massive clusters fully clear their surroundings after about five million years, while lower-mass clusters take between seven and eight million years to emerge. The faster emergens means massive cluster begin exerting stellar feedback through winds, ultraviolet radiation and eventual supernovae, dispersing the unused gas sooner.
A deeper understanding of galaxy evolution
The research addresses long-standing questions on the factors that determine how quickly clusters displace their birth clouds, something that simulations of star formation and stellar feedback have struggled to reproduce. The new research provides important new constraints to the process. The feedback from star clusters, and how they stir up the raw material, affects subsequent formation of clusters. The research refines models of galaxy evolution, clarifying when ultraviolet feedback is the strongest. Faster gas clearance also exposes protoplanetary disks to intense UV radiation, providing them with less time to accrete material and assemble planets. A paper describing the research has been published in Nature Astronomy.
