James Webb Space Telescope Reveals True Size of Early Galaxies

Recent observations from the James Webb Space Telescope (JWST) have challenged previous assumptions about the size of galaxies in the early universe. Scientists were previously puzzled by the apparent size of these ancient galaxies, which seemed to defy the standard model of cosmology. The JWST, with its advanced infrared capabilities, has now shed light on the matter, revealing that some of these early galaxies are not as massive as previously thought.

Understanding the misunderstanding

Astronomers initially found that early galaxies appeared much larger than expected, suggesting a potential crisis in our understanding of the evolution of the universe. This discrepancy was attributed to a miscalculation of the masses of the galaxies, partly due to the influence of black holes. Black holes, despite their name, can make galaxies appear brighter and more massive by emitting intense light from gas falling into them. This effect was not fully accounted for in previous observations.

Revised Galaxy Dimensions

Dr. Steve Finkelstein, an astrophysicist at the University of Texas at Austin, and his team have now corrected these estimates. They focused on 261 galaxies from between 700 million and 1.5 billion years after the Big Bang. By examining the infrared light captured by the JWST, which is sensitive to cooler, lower-mass stars, the researchers were able to make a more precise measurement of the true sizes of these galaxies.

The findings indicate that some galaxies are larger than previously thought, but they do not challenge the standard model of cosmology.

Future implications

Despite the revised numbers, the JWST still reveals that the early universe had more galaxies than predicted. This discrepancy may be due to faster star formation rates in the early universe compared to today. The coming months will provide more data to help understand how these galaxies gathered their stellar mass and how they formed.