Faintest distant galaxy discovered

Posted by Kate Taylor

Astronomers at Arizona State University have found the faintest galaxy yet, one of the ten most distant objects currently known in space.

They've observed it only about 800 million years after the beginning of the universe, using the IMACS instrument on the Magellan Telescopes at the Carnegie Institution's Las Campanas Observatory in Chile.

The faint infant galaxy is located 13 billion light-years away. It's one of only a few galaxies detected at a red shift of more than seven, and is fainter than any of the others.

"This galaxy is being observed at a young age. We are seeing it as it was in the very distant past, when the universe was a mere 800 million years old," says associate professor James Rhoads.

"This image is like a baby picture of this galaxy, taken when the universe was only five percent of its current age. Studying these very early galaxies is important because it helps us understand how galaxies form and grow."

Designated LAEJ095950.99+021219.1, the galaxy is extremely faint and was detected by the light emitted by ionized hydrogen. The search used special narrow-band filters that allow a small wavelength range of light through.

"With this search, we've not only found one of the furthest galaxies known, but also the faintest confirmed at that distance," says associate professor Sangeeta Malhotra.

"Up to now, the redshift seven galaxies we know about are literally the top one percent of galaxies. What we're doing here is to start examining some of the fainter ones – thing that may better represent the other 99 percent."