New spin on galaxy formation.

In studying distant gas clouds that may rank among the universe's earliest examples of galaxies in the making, astronomers have uncovered a puzzling property. Observed as they appeared when the cosmos was only 20 percent of its current age, these gaseous objects seem to rotate about twice as fast as several popular models of galaxy formation predict.

Their speed of rotation--about 220 to 250 kilometers per second at their edge--is comparable to that of the Milky Way today. Study collaborator Jason X. Prochaska says he finds it perplexing that galaxies had such a high rotation rate early in the universe. If fledgling galaxies in the youthful cosmos already had the spin of today's Milky Way, their increased rotation rate after several billion years of evolution might cause them to break apart instead of forming the galaxies seen in nearby regions of the modern universe.

"If this result holds up as we look at more [distant] objects, it is going to change the way people look at galaxy formation," says study coauthor Arthur M. Wolfe.

He and Prochaska, both of the University of California, San Diego, used the 10-meter W.M. Keck Telescope atop Hawaii's Mauna Kea to examine the gas clouds. Wolfe and Prochaska inferred the presence of the faraway clouds by analyzing the absorption of light emitted by quasars behind them. The researchers found characteristic asymmetries in the shape of absorption lines created by silicon, nickel, and iron in the clouds. These asymmetries, believed to signify rotation, indicate that the clouds spin at an unexpectedly high rate, Wolfe and Prochaska assert.