UC Berkeley postdoctoral fellows investigate early universe

SRT Collaboration/Courtesy
A telescope located in Antarctica contributed to research done in Berkeley.

The formation of the universe after the Big Bang may not have happened exactly as you — or scientists — used to think.

Research published Sept. 1 in the Astrophysical Journal and conducted in part by scientists from the UC Berkeley Center for Cosmological Physics has found that the first massive galaxies that bloomed into existence more than 13 billion years ago were explosive events that occurred more quickly than was previously thought.

To come to that conclusion, UC Berkeley postdoctoral physics fellows Oliver Zahn and Christian Reichardt led a data analysis of temperature fluctuations that were left over from the Big Bang and visible through the South Pole Telescope in Antarctica. The telescope is the largest ever constructed at the South Pole, according to the University of Chicago website for it.

The study, which was also conducted by researchers from the University of Chicago, took the data from the telescope to make 12 maps of four different regions in the sky with three different light wave frequencies, Zahn said.

That data provided a new time frame for the universe’s first era of forming galaxies, called the “Epoch of Reionization” — a time when early stars came to life in a massive gas cloud.

The light that shone from these stars has been theorized to have created ionized gas in and around the galaxies, creating enormous “ionization bubbles” that left a lasting, telltale signature in the cosmic background radiation that can provide information about the galaxies that existed there before, according to Zahn.

“Studying reionization is currently a hot topic, partly of course because it is starting to happen at or just beyond the limits of current telescopes,” Reichardt said.

The new finding does not debunk previous theories on early galaxy inception but instead provides a clearer picture because it is able to give a more specific start and end time to the epoch when early galaxies came to life, Zahn said.

According to UC Berkeley astronomy graduate student Matt George, prior to this, researchers did not have much knowledge about the reionization process “other than that it happened.” This study provides information about stars and galaxies in the early universe by placing constraints on how long the development of massive galaxies after the Big Bang took.

“It’s a neat technique and the first measurement of its kind, teasing out a signal from the microwave background radiation,” George said.

All new research is always built on the back of old research, Zahn said.

“Imagine having an extremely blurry image of something and when you blink it looks like a hippo, then you are given a higher-resolution version that clearly shows that is an elephant, without debunking the previous data,” Zahn said in a statement.

Contact Aliyah Mohammed at [email protected]