Hubble, the space telescope that launched in 1990 and collects data to this day, “has long showed an excess of elongated galaxies,” explained co-author Marc Huertas-Company, a faculty research scientist at the Institute of Astrophysics on the Canary Islands. But researchers still wondered: Would additional detail show up better with the sensitivity to infrared light that the Webb telescope, which launched in 2021, has? “Webb confirmed that Hubble didn’t miss any additional features in the galaxies they both observed. Plus, Webb showed us many more distant galaxies with similar shapes, all in great detail,” Huertas-Company said.
One question, of course, is why early galaxies tended to be so flattened and elongated. One hypothesis, Pandya explained, is that the early universe may have been filled with filaments of dark matter that formed a kind of “skeletal background,” or “cosmic highway,” that ushered gas and stars along it. These filaments still exist, but they have grown much more diffuse as the universe has expanded, so they may be less likely to promote the formation of breadstick-shaped galaxies.