The illustration is courtesy of Daniel Kelson. CMB data is based on observations obtained with Planck, an ESA science mission with instruments and contributions directly funded by ESA Member States, NASA, and Canada.
The universe's first structure originated when some of the material flung outward by the Big Bang overcame its trajectory and collapsed on itself, forming clumps. A team of Carnegie researchers showed that denser clumps of matter grew faster, and less-dense clumps grew more slowly. The group's data revealed the distribution of density in the universe over the last 9 billion years. (On the illustration, violet represents low-density regions and red represents high-density regions.) Working backward in time, their findings reveal the density fluctuations (far right, in purple and blue) that created the universe's earliest structure. This aligns with what we know about the ancient universe from the afterglow of the Big Bang, called the Cosmic Microwave Background (far right in yellow and green). The researchers achieved their results by surveying the distances and masses of nearly 100,000 galaxies, going back to a time when the universe was only 4.5 billion years old. About 35,000 of the galaxies studied by the Carnegie-Spitzer-IMACS Redshift Survey are represented here as small spheres.