Astronomers say they've made a startling discovery, a young galaxy acting in surprisingly mature manner, more like typical fully developed galaxy examples such as our own Milky Way.
Tagged as galaxy S0901, it has been observed rotating in a calm manner usually found in older settled galaxies, they say.
"Usually, when astronomers examine galaxies in an early era, they find that turbulence plays a much greater role than it does in modern galaxies," James Rhoads of Arizona State University said in a release from NASA's Jet Propulsion Laboratory in Pasadena, California. "But S0901 is a clear exception to that pattern."
The galaxy is 10 billion light years from Earth, so we are seeing it as it looked when comparatively young.
"This galaxy is the equivalent of a 10-year-old. I can tell you from watching my kids' classes that 10-year-olds like to fidget!" said Rhoads, lead author of a study published in the Astrophysical Journal.
"S0901 is unusual because it's not fidgeting, and instead is very well behaved."
Galaxies form and accumulate mass as their gravity attracts surrounding clouds of gas that fall into the growing galaxy in haphazard orbits, which creates turbulence which can push star formation.
This motion in S0901 was considerably smoother than what was expected, the researchers said.
"Galaxies 10 billion years ago were making stars more actively than they do now," says study participant Sangeeta Malhotra, also of Arizona State. "They usually also show more turbulence, likely because they are accumulating gas faster than a modern galaxy does."
"But here we have cases where an early galaxy combines the calm rotation of a modern one with the active star formation of their early peers," she says.
More observations should reveal if there are other galaxies acting older than their age or if S0901 is just strangely just "mature for its age," the researchers say.
S0901 was observed using the Herschel space observatory, a European Space Agency undertaking to which NASA contributes.
"This is a truly surprising result that reminds us that we still don't understand many details of the evolution of the universe," JPL Herschel scientist Paul Goldsmith says. "Facilities like Herschel help us understand this complex story."
