Starship Asterisk*

This infrared image from NASA’s James Webb Space Telescope (JWST) was taken for the JWST Advanced Deep Extragalactic Survey, or JADES, program. It shows a portion of an area of the sky known as GOODS-South, which has been well studied by the Hubble Space Telescope and other observatories. More than 45,000 galaxies are visible here. ~ Image Credit: NASA, ESA, CSA, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Marcia Rieke (Arizona), Daniel Eisenstein (CfA). Image Processing: Alyssa Pagan (STScI)

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Among the most fundamental questions in astronomy is: How did the first stars and galaxies form? NASA’s James Webb Space Telescope is already providing new insights into this question. One of the largest programs in Webb’s first year of science is the JWST Advanced Deep Extragalactic Survey, or JADES, which will devote about 32 days of telescope time to uncover and characterize faint, distant galaxies. While the data is still coming in, JADES already has discovered hundreds of galaxies that existed when the universe was less than 600 million years old. The team also has identified galaxies sparkling with a multitude of young, hot stars.

“With JADES, we want to answer a lot of questions, like: How did the earliest galaxies assemble themselves? How fast did they form stars? Why do some galaxies stop forming stars?” said Marcia Rieke ...

Ryan Endsley ... led an investigation into galaxies that existed 500 to 850 million years after the big bang. This was a crucial time known as the Epoch of Reionization. For hundreds of millions of years after the big bang, the universe was filled with a gaseous fog that made it opaque to energetic light. By one billion years after the big bang, the fog had cleared and the universe became transparent, a process known as reionization. Scientists have debated whether active, supermassive black holes or galaxies full of hot, young stars were the primary cause of reionization.

As part of the JADES program, Endsley and his colleagues studied these galaxies with Webb’s NIRSpec (Near-Infrared Spectrograph) instrument to look for signatures of star formation – and found them in abundance. “Almost every single galaxy that we are finding shows these unusually strong emission line signatures indicating intense recent star formation. These early galaxies were very good at creating hot, massive stars,” said Endsley ...