
Such a galaxy string would be no big deal in the present-day universe. It's similar to the famous Great Wall of galaxies just a few hundred million light-years away. But the best models of structure formation predict no gatherings so big appearing so early in cosmic history. "The universe was growing up faster than we thought it was," said Povilas Palunas (McDonald Observatory), one of the discoverers, at the American Astronomical Society meeting on Wednesday. "Our results are consistent with others that are coming from this meeting," he added, referring in particular to the recent discovery of big, mature galaxies that existed before theory says they should (see story below).
Team member Bruce Woodgate (NASA/Goddard Space Flight Center) described how the astronomers first began to suspect something funny. They noticed two quasars 30 million light-years apart in the early universe showing spectral signs that the same, huge gas cloud was filtering the light of both. Gas clouds, even the ones that pervade galaxy clusters, shouldn't be that big. Further investigation turned up 36 galaxies and one quasar grouped at the same distance (redshift) in an even larger, ragged band at least ½° long on the sky. In fact the band runs off both edges of the field the astronomers surveyed. They intend to go back at the first opportunity and try to determine its full extent. They also plan to survey other patches of sky to see if such early structures are common.

"We're looking at the galaxies; we're not looking at the mass," stressed team member Gerard M. Williger (Johns Hopkins University). "We'd love to look at the mass, but that's very, very hard."