Scientists Find Galaxies Started Birthing Stars Right After Big Bang

According to a new study published in Nature on March 14, led by Joaquin Vieira, a scholar at Caltech in Pasadena, massive galaxies started giving birth to stars soon after the Big Bang which is far earlier than scientists previously have thought.

The study discovered that galaxies started making stars as early as 1 billion years after the Big Bang, which sparked the beginning of the universe about 13.7 billion years ago.

"These types of galaxies, which are massive dusty galaxies that are forming stars — these are the most active locations of star formation in the universe," said Joaquin Vieira.

Among the twenty-six galaxies observed, the median age was twelve billion years, making them some of the oldest star-forming galaxies known.

"These galaxies reveal star formation at an extraordinary rate, when the universe was very young. I don't think anyone expected us to find galaxies like this so early in the history of the universe," Vieira added.

An international team of astronomers discovered dozens of these galaxies with the National Science Foundation- (NSF) funded South Pole Telescope (SPT). The researchers used the Antarctic's SPT to identify high-redshift galaxies. That telescope is designed to look at the Big Bang's afterglow, also known as the cosmic microwave background, but it is sensitive enough to ferret out interesting and old galaxies based on their color.

SPT is a 10-meter dish in Antarctica that investigates the sky in millimeter-wavelength light, whose waves fall between radio waves and infrared on the electromagnetic spectrum.

The international team of astronomers were also able to come up with more detailed analysis of the galaxies using the new Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which is designed to see through the dust in galaxies and young stars.

"We had been waiting five years for ALMA, so by the time it turned on we were ready with a full catalog of sources," Vieira said.

In a statement released Friday, Vieira said that the study discovered galaxies with a redshift of 6, making them some of the oldest galaxies ever discovered. Two of the redshifts were measured at 5.7 – the highest known measure for any galaxy of this type, placing them within the first billion years of the universe’s life, said Vieria.

Through this study astronomers will have an additional tool for measuring galaxies and star formation. Instead of relying on a complicated combination of radio observations and indirect optical using multiple telescopes to study the galaxies, the team utilized gravitational lensing techniques.

The findings are published in the journal Nature