Astronomers Use Advanced Instruments to Calculate More Accurate Age of Maisie’s Galaxy
Astronomers have made a groundbreaking discovery about the age of Maisie’s galaxy, which was initially spotted by the James Webb Space Telescope (JWST) in June 2022. Using advanced instruments, scientists have determined that although Maisie’s galaxy is not as old as originally thought, it is still one of the oldest systems recorded in history.
The galaxy, located around 390 million years after the Big Bang, is estimated to be approximately 13.4 billion years old. This makes it a mere 70 million years younger than JADES-GS-z13-0, the currently known oldest star system.
Led by astronomer Steven Finkelstein from the University of Texas at Austin, a team discovered Maisie’s galaxy last summer. It was named in honor of Finkelstein’s daughter, as they spotted it on her birthday. Initially, the group believed that the galaxy was only 290 million years old. However, with the help of more advanced equipment, their analysis revealed that it is approximately 100 million years older than their initial estimate.
Finkelstein expressed his excitement about Maisie’s galaxy, explaining that it was one of the first distant galaxies identified by JWST and also the first to be spectroscopically confirmed among that set of galaxies. Spectroscopic confirmation was made possible by the JWST’s Near InfraRed Spectrograph (NIRSpec), conducted by the Cosmic Evolution Early Release Science Survey (CEERS). NIRSpec splits an object’s light into various narrow frequencies to accurately determine its chemical composition, heat radiation, intrinsic brightness, and relative motion.
In the case of Maisie’s galaxy, the redshift, which indicates the movement of light away from the observer, played a crucial role in obtaining a more precise estimate. With a redshift of z=11.4 assigned to the galaxy, the researchers were able to settle on the revised estimation of the galaxy’s age being 390 million years after the Big Bang.
The team of astronomers also examined another galaxy, CEERS-93316, which was initially estimated to exist 235 million years before the Big Bang. However, after further study, its redshift was found to be z=4.9, placing it at only one billion years after the Big Bang. The incorrect initial estimate was due to the galaxy emitting an unusually high amount of light in narrow frequency bands associated with oxygen and hydrogen, giving it a misleading blue appearance.
Finkelstein attributed this misjudgment to bad luck and referred to it as a “weird case.” He stated that out of the numerous high redshift candidates that have been spectroscopically observed, CEERS-93316 was the only instance of the true redshift being significantly lower than the initial guess. Finkelstein believes that this outcome was probably the most likely because of the galaxy’s extreme brightness and apparent high redshift.
With the revised estimation for Maisie’s galaxy, the CEERS team is now investigating approximately 10 more systems that could potentially be older than Maisie’s galaxy. These ongoing studies present an exciting opportunity for astronomers to uncover more about the universe’s early history and the formation of ancient galaxies.