Hubble study finds dwarf galaxies retain only 11 per cent of oxygen
Researchers discovered that most oxygen produced by stars in 37 nearby dwarf galaxies appears to have been blown into space.
Researchers using the Hubble Space Telescope found that 37 nearby dwarf galaxies retained an average of only 11 per cent of the oxygen produced by their stars, according to a Times of India report. The study, published on Monday in The Astrophysical Journal, revealed that these galaxies held between 4 per cent and 25 per cent of their expected oxygen.
The findings were part of the Galaxies Losing Oxygen via Winds (GLOW) project, which is funded by NASA and the National Science Foundation. Scientists used archival Hubble observations alongside data from the retired Spitzer Space Telescope and ground-based radio telescopes to examine the galaxies.
The research suggests that powerful stellar explosions create galactic winds that carry oxygen-rich material away from these systems. Because dwarf galaxies have low mass and weak gravitational pull, they struggle to hold onto gas produced by stars compared to larger galaxies.
University of Utah assistant professor Grace Telford, a co-investigator, said the oxygen must have been inside the galaxies at some point because their stars produced it. She noted that for the oxygen to be missing, it must have been pushed out, a process requiring significant energy from massive stars and supernovae.
Astronomers are still investigating the final location of the missing 89 per cent of oxygen. It may reside in the circumgalactic medium, which consists of diffuse gas clouds surrounding galaxies, or it may have travelled further into the space between galaxies.