It first appeared as a glowing blob from ground-based telescopes and then vanished completely in images from the Hubble Space Telescope. Now, the ghostly object has reappeared as a faint, yet distinct galaxy in an image from the James Webb Space Telescope (JWST).
Astronomers with the COSMOS-Web collaboration have identified the object AzTECC71 as a dusty star-forming galaxy. Or, in other words, a galaxy that’s busy forming many new stars but is shrouded in a dusty veil that’s hard to see through—from nearly 1 billion years after the Big Bang. These galaxies were once thought to be extremely rare in the early universe, but this discovery, plus more than a dozen additional candidates in the first half of COSMOS-Web data that have yet to be described in the scientific literature, suggests they might be three to 10 times as common as expected.
“This thing is a real monster,” said Jed McKinney, a postdoctoral researcher at The University of Texas at Austin. “Even though it looks like a little blob, it’s actually forming hundreds of new stars every year. And the fact that even something that extreme is barely visible in the most sensitive imaging from our newest telescope is so exciting to me. It’s potentially telling us there’s a whole population of galaxies that have been hiding from us.”
If that conclusion is confirmed, it suggests the early universe was much dustier than previously thought.
The team published its findings in The Astrophysical Journal.
A comparison of Hubble Space Telescope’s image of AzTECC71 and the corresponding image from the James Webb Space Telescope. Credit: J. McKinney/M. Franco/C. Casey/University of Texas at Austin
2023-12-03 19:41:03
Original from phys.org