“Seeing an object within the first billion years is remarkable because the universe was fully ionized, that is, it was too hot and too uniform to form anything for the first 400 million years,” said Min Yun, an astrophysicist at the University of Massachusetts Amherst who participated in the research, in a statement. “So our best guess is that the first stars and galaxies and black holes all formed within the first half a billion to one billion years. This new object is very close to being one of the first galaxies ever to form.”
Objects such as G09 83808 are difficult to see because they are surrounded by gigantic dust clouds, keeping them out of view from observatories such as the Hubble Space Telescope, which best observes in visible and infrared wavelengths. The LMT is better positioned to look at objects of this kind because it uses millimeter-length wavelengths that can peer through obscuring dust.
Gravitational lensing also helped the astronomers with observations. This phenomenon magnifies light as it passes by a large object, making more distant objects look larger. G09 83808 appeared 10 times brighter and closer than it actually is because there is a large galaxy in between the object and Earth, which helped magnify G09 83808 through gravitational lensing.
LMT will be fully operational this winter and able to peer at more objects that are very old and have a high redshift. Redshift refers to the speed at which the universe expands. More distant objects have a larger redshift.
The redshift of G09 83808 was confirmed through observations of the spectral lines of carbon monoxide, which were shifted into the red end of the spectrum. The redshift was independently corroborated with the Smithsonian Submillimeter Array on Mauna Kea, Hawaii, in association with astronomers at the Harvard-Smithsonian Center for Astrophysics.