Direct neutral gas found in galaxies 700M yrs post-Big Bang

What happened

Additionally, they searched for ionized gas, also called the [N II] 205 µm emission line, to confirm their findings. This is a gas whose atoms have yet to be corrupted by solar radiation, hence its name and vital purpose in potentially forming the first stars in the universe.

ALMA was used for this research since neutral gas does not emit ultraviolet, optical, or infrared light, meaning more powerful space-based telescopes like NASA’s James Webb Space Telescope (JWST) and Hubble Space Telescope (HST) can’t observe it. After identifying little to no evidence of this ionized gas, the researchers concluded that the four galaxies are comprised of neutral gas.

After comparing this data with JWST data, the researchers ascertained these four galaxies exhibit high densities of stars compared to present-day galaxies, the latter of which exhibit widely dispersed stars. Objects whose z value is greater than 0 are moving away from the observer while objects whose z value is less than 0 are traveling closer to the observer.