James Webb Space Telescope reveals gravitational lensing in MACS J0454 cluster

New observations and research are advancing the understanding of galaxy formation and the role of gravitational lensing. Using the NIRCam instrument on the James Webb Space Telescope, images of the galaxy cluster MACS J0454.1-0300 in the Orion constellation reveal how the cluster's mass acts as a gravitational lens. This effect deflects light from much more distant background galaxies, stretching them into reddish arcs and causing single galaxies to appear in multiple locations.

Complementing these visual observations, the international MEGATRON project has released findings regarding the circumgalactic medium—the vast gas halos surrounding galaxies. Through high-precision cosmological simulations, researchers have discovered that these gas halos maintain a 'memory' of their history, meaning their properties do not adjust instantly to changes in temperature or environment. These findings provide a more nuanced framework for interpreting data from the James Webb Space Telescope and understanding how light, chemistry, and matter exchange shape the growth of galaxies from their earliest stages.