Using high-resolution images, NIRCam, a near-infrared camera aboard the NASA/ESA/CSA James Webb Space Telescope, has led astronomers to discover COSMOS-74706, one of the earliest known barred spiral galaxies. This discovery is pivotal in shaping our understanding of cosmic evolution.
COSMOS-74706: Unsharp mask overlaid on F200W, F277W, and F356W filter configurations. The white lines represent logarithmic spirals along the galaxy’s arm structure while the lines indicate the north-south bar structure. Image credit: Daniel Ivanov.
The barred spiral galaxy COSMOS-74706 existed approximately 11.5 billion years ago.
“This galaxy developed its bar just two billion years after the universe’s inception,” stated Daniel Ivanov, a graduate student at the University of Pittsburgh.
“Stellar bars are linear features found at the centers of galaxies, confirming their namesakes.”
COSMOS-74706’s bar comprises a dense collection of stars and gas, appearing as a bright line bisecting the galaxy when viewed perpendicularly to its plane.
Stellar bars significantly influence a galaxy’s evolution, funneling gas from the outskirts into the center, which feeds the supermassive black hole and can inhibit star formation within the galactic disk.
While previous reports identified barred spiral galaxies, their analyses were inconclusive due to the less reliable optical redshift methods compared to the spectroscopy used for COSMOS-74706 verification.
In some instances, a galaxy’s light was distorted by a massive object, leading to a phenomenon known as gravitational lensing.
“Essentially, COSMOS-74706 is the most redshifted spectroscopically confirmed lensless barred spiral galaxy,” Ivanov noted.
“We were not surprised to find barred spiral galaxies so early in the universe’s timeline.”
“In fact, some simulations suggest the bar formed at redshift 5, or roughly 12.5 billion years ago.”
“However, I believe we shouldn’t expect to find many of these galaxies just yet.”
This discovery helps refine the timeline for bar formation, making it a significant finding.
Ivanov and colleagues presented their discoveries on January 8th during the 247th Annual Meeting of the American Astronomical Society.
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Daniel Ivanov et al. 2026 zspec>3 barred spiral without lens. AAS247
Source: www.sci.news
