Faintest, Furthest Galaxy Discovered

Scientists from UC Davis using the Hawaiian observatory have detected what is confirmed to be the faintest, furthest galaxy ever to be discovered.

The early-universe galaxy is located approximately 13 billion light years distance from Earth.

This new finding could help scientists understand the universe specter when the first stars were born and the “reionisation epoch” began.

The special 10-meter Hubble Space Telescope along with gravitational lensing from the Hawaiian W. M. Keck Observatory allowed the team of astronomy scientists to see the astonishingly far and faint object.

The galaxy would have never been confirmed if it hadn’t been for the gravitational lens, commented Kuang-Han Huang, a researcher at the Davis University of California.

Gravitational lensing, an instrument made possible by Einstein’s prediction, uses the force of gravity that bends the path of light between another object and its viewer to magnify a distant galaxy (or the observed object) through highly potent lenses.

In this example, the galaxy discovered was behind MACS2129.4-0741, a galaxy cluster massive enough to help the instrument create three images of the faint galaxy. The images were confirmed to be of the same object because they showed “similar spectra.”

The images were observed separately in the Hubble Space Telescope data and the Keck Observatory, but the Deep Imaging and Multi-Object Spectrograph (DEIMOS) instrument confirmed the records were of the same object.

Marusa Bradac, UC Davis professor and study leader, said the power of the Keck Observatory instruments, paired with the gravitational lenses, allowed “us to truly see where no human has seen before.”

Being such a far and therefore old galaxy, this “tiny” object (extremely low in stellar mass, approximately 1% of the Milky Way Galaxy) lies at the finish of the reionisation epoch when galaxy transitioning hydrogen passed from being mostly neutral to being ionized. It was the time the first stars appeared.

According to Huang’s statement, this new data could offer a clue to the understanding of why approximately 13 billion years ago hydrogen suffered such a significant modification. It’s a fundamental question astronomy is trying to answer. After that chemical shift, “matter became more complex,” said Keck Observatory astronomer, Marc Kassis.

The study on the furthest galaxy, published in the Astrophysical Journal Letters could now unveil hidden mysteries from the universe and its early days.

Image source: Wikimedia