Magazine article Science News

More Dark Galaxies Reveal Themselves: Hundreds of Nearly Starless Suspects Found in Nearby Cluster

Magazine article Science News

More Dark Galaxies Reveal Themselves: Hundreds of Nearly Starless Suspects Found in Nearby Cluster

Article excerpt

Hundreds of shady characters are lurking in a nearby neighborhood of galaxies. The Coma cluster houses nearly 20 times as many dark galaxies as previously known, researchers report. These shadowy figures--some as large as the Milky Way but with just one-thousandth the number of stars--could be dead ends in galactic evolution.

The cluster houses at least 854 of these barely perceptible galaxies, and there could be well over 1,000. These "ultra-diffuse galaxies" appear to have had much of their star-forming gas stolen, Jin Koda, an astronomer at Stony Brook University in New York, and colleagues report. The findings appear online June 24 in Astrophysical Journal Letters.

Last year, another team found 47 ultra-diffuse galaxies in the Coma cluster (SN: 12/13/14, p. 9), a bevy of thousands of galaxies that sits roughly 330 million light-years away in the constellation Coma Berenices. Koda and colleagues wondered if a bigger telescope could find even more dark galaxies, so they dug through images of the cluster taken by the 8-meter-wide Subaru Telescope in Hawaii.

"It's a beautiful result," says Yale astronomer Pieter van Dokkum, who led the discovery of the first 47 dark galaxies.

These galaxies are relics from an earlier time. They haven't formed any stars in the last 4 billion to 10 billion years, Koda says. The galaxies aren't scattered around the cluster haphazardly, as would be expected if they were new arrivals falling into Coma randomly. They are instead arranged symmetrically around the heart of the cluster, indicating that they have been lurking within Coma for a long time. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.