Astronomers have long debated which type of star plays the greatest role in enriching galaxies with heavier elements. The recent study using the James Webb Space Telescope (JWST) has provided conclusive evidence that smaller, more sunlike stars, specifically thermally pulsing AGBs, are responsible for this process.
Unlike massive stars that explode as supernovae, sending enriched material into space, smaller stars like our Sun undergo a slower, more prolonged process. When these stars exhaust their fuel, they swell and contract, causing the core to heat up again. This “thermally pulsing” phase creates AGBs, which are incredibly efficient at enriching galaxies with rare elements such as vanadium and zirconium.
The JWST’s NIRSpec camera allowed researchers to capture high-resolution infrared spectra of three young galaxies, revealing a strong presence of carbon and oxygen bands, characteristic of AGB remnants. This finding confirms the 20-year-old model that smaller stars play a greater role in chemical enrichment than previously thought. The study provides new insights into the history of galaxy formation and evolution, shedding light on how our cosmos came to be.
Source: https://www.universetoday.com/169140/webb-confirms-a-longstanding-galaxy-model