Nearby Relic Galaxy Has Remained Unchanged Since the Universe Began
Big galaxies suck — and no, I’m not being rude. I just mean that they absorb other, smaller galaxies when they run into each other, like a cannibalistic version of bumper cars. It’s how they survive. But some galaxies manage to avoid collisions, and one in a thousand keep all their properties from formation intact. Now, researchers have found one of those oldies, also called a relic galaxy, in our cosmic neighborhood.
Its name is NGC 1277. It has a “million million” stars. It’s at the center of the Perseus cluster, the biggest concentration of galaxies near the Milky Way, which is about 225 million lightyears away from us. In other words, it would take the Millennium Falcon 27 years to get there, if Han Solo was piloting. That seems really far — especially since we can’t travel in hyperspace yet — but it’s actually relatively close.
Best of all, we can affectionately refer to NGC 1277 as a “red nugget” galaxy, thanks to its un-evolved, high-redshift color distribution. NGC 1277 looks the same as it did 12 billion years ago (for context, the universe has only been around for about 13.8 billion years). It’s the fully intact Tyrannosaurus skeleton of the universe.
Researchers Michael Beasley and Ignacio Trujillo of the Instituto de Astrofísica de Canarias and the University of La Laguna were able to confirm the relic status of NGC 1277 by studying its globular clusters with the Hubble Space Telescope. What they saw was a massive expanse of — you guessed it — red.
Globular clusters are groups of stars formed at the birth of a galaxy that orbit its outskirts. Red clusters are composed of more heavy elements than helium and orbit closer to the galaxy’s center. Blue clusters have fewer metals and are seen only as a result of galactic collisions. NGC 1277 only has red clusters, the largest galaxy of its size to have been observed without them.
That means every star formed in NGC 1277 was formed within 100 million years of its birth, within the first billion years of the universe’s existence. The Milky Way’s rate of one star a year pales in comparison to NGC 1277’s 1,000 stars a year. This makes for a perfect opportunity to study a vast galaxy that remains basically unchanged since the dawn of everything.
So, how did NGC 1277 last all these billions of years without accumulating blue clusters? Beasley and Trujillo think that NGC 1277 formed as a satellite to the central galaxy of the Perseus cluster, which absorbed any material that could have impacted its satellite. Now, NGC 1277 still orbits that central galaxy, at 1,000 kilometers a second. Beasley and Trujillo are hoping to observe more global clusters with the Hubble to find even more relic galaxies.