Lowell Astronomer Studies Strange Galaxy Alignments

Jun 26, 2017

An astronomer at Lowell Observatory used the Hubble Space Telescope to peer back in time at very distant galaxies. He found their position in space isn’t random; it’s influenced by other galaxies nearby. KNAU’s Melissa Sevigny reports on the new research.

Credit ESA/Hubble, NASA, HST Frontier Fields


Elliptical galaxies are clumps of stars shaped like a football. Astronomer Michael West studied 65 massive ones located at the center of galaxy clusters.  

"So a cluster of galaxies is like a city of galaxies," West says. "There’s hundreds or thousands of galaxies all dancing around each other because of gravity. They’re flattened systems, generally, they’re elongated. And it turns out the biggest galaxy that resides in them is elongated in the same direction. So it knows about its surroundings."

West found these strange alignments were already in place 10 billion years ago. He’s not sure why this happens. It might be related to how big galaxies devour little ones along particular lines in space.

"I picture it like a giant spider in a spider web," West says. "It’s waiting for its next meal, only its next meal isn’t a small insect, it’s a small galaxy. The big galaxy gets fed along certain directions, certain strands. That’s why it turns in those directions to feed, essentially."

The next step is to look further back in time, to see if galaxies weren’t always this way.