The oldest, most-distant galaxy is so far away, we’re literally looking at the universe’s early years to study it.
Space is big. Really, really, really big – on a scale the human mind can have trouble comprehending. It took the Voyager satellite nearly 40 years just to leave our solar system, and that’s barely a fraction of the universe’s size. So when I say science has a new record for the most-distant galaxy from Earth, it’s a phenomenal distance. That galaxy is EGS-zs8-1, and you can reach it in a mere 13.1 billion light years.
Or rather, you would have reached it if you’d started the trip billions of years ago. EGS-zs8-1 is so far away that it’s showing light from the early years of the universe – when all of known space was 670 million years old. If you take universal expansion into account, EGS-zs8-1 is more likely to be 30 billion light years away by now.
“We’re actually looking back through 95% of all time to see this galaxy,” UC Santa Cruz astronomer Garth Illingworth explained. “It’s really a galaxy in its infancy … when the universe was in its infancy.”
So what’s it like being a galaxy in the early days of the universe? In EGS-zs8-1’s case, incredibly hectic. The galaxy is churning out new stars at 80 times the rate our Milky Way does today. That makes EGS-zs8-1 far brighter than other galaxies from that distance, which almost led scientists to believe the galaxy was closer to us. It was only when astronomers confirmed its redshift – how fast its moving away from us – that it took the record for the most distant galaxy from Earth.
Not that the team behind this study believe EGS-zs8-1 will be the record holder for long. “You don’t get to be record holder very long in this business,” Illingworth said, “which is good because ultimately we are trying to learn about the universe. So more is better.”
Source: The Astrophysical Journal Letters, via LA Times
Published: May 6, 2015 03:38 pm