Astronomers with the UC Davis Leafs team have made a historic breakthrough in the exploration of deep space. In a study recently published in the journal, “Nature Astronomy,” Austin Hoag, a Davis graduate student and lead author of the paper, described some of the most distant objects in the known universe. Because of the speed of light, the farther away an object is, the more distant in the past do we observe it, making this a primordial galaxy.
How did we find this distant, primordial galaxy?
This means it traces back to the earliest detectable time in the universe when everything was just beginning to coalesce from the initial vast cloud of ionized hydrogen, blocking out most visible light. Then, as stars and eventually galaxies began to form, this light escaped and is now reaching us over 13 billion years later. While there are many such galaxies out there, this one was in a perfect position behind a giant cluster of 155 galaxies, the gravity of which focused the brightness of z7p64 by more than ten times.
Using the ground-based Keck I Telescope on Mauna Kea, Hawaii, lead physicist, Maruša Bradač, was able to determine that z7p64 is a young, star-forming galaxy with a mass of about 300 million suns. That is about .05% of the mass of the Milky Way. Hoag believes this is much more representative of the earliest galaxies in the universe than some of the larger, later objects they have found.
“Most objects that we’ve seen at that distance are extremely bright and probably rare compared to other galaxies. We think this galaxy is much more representative […].”