Two Galaxies Collided and Now There's an Intergalactic 'Eye' Watching Us All
Peer into this galactic eyelid.
Image: Astrophysical Journal
We're being watched, from 114 million light-years away. Nah, we're probably alone in the Universe on this overheating marble, but now there's a galactic eye in the mix.
The "eye" was caught in a staring contest with the Atacama Large Millimeter/submillimeter Array (ALMA), marking a rare moment for astronomy. To form this ocular shape, a galaxy named IC 2163 collided with another spiral galaxy, NGC 2207, sending them spinning into the shape we see here. Their outer spiral arms scraped each other and swung into a spiraling dance. The report on the ocular formation is published today in the Astrophysical Journal.
It's pretty unusual to catch galaxies in this stage, lead author notes Michele Kaufman in a news release. "Galactic eyelids last only a few tens of millions of years, which is incredibly brief in the lifespan of a galaxy." The Milky Way, for reference, is about 13 billion years old. "Finding one in such a newly formed state gives us an exceptional opportunity to study what happens when one galaxy grazes another."
The eye is crying molecular gas-tears that flow at 223,694 miles per hour in the outer portion of IC 2163. As it flies from the outer to inner bands, the gas becomes more dense, piles up, and creates new star clusters.
The young galactic tear-filled eye joins several equally emo observations by ALMA, including black hole rainstorms, a "dinosaur egg" known as Firecracker, and the coldest place in the Universe outside of the creative hearts of these astronomers.