Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

Spitzer discovers strange new "species" of ultra-red galaxies

The newfound galaxies are more than 60 times brighter in the infrared than they are at the reddest colors Hubble can detect.
Red-galaxies
This artist's conception portrays four extremely red galaxies that lie almost 13 billion light-years from Earth. Discovered using the Spitzer Space Telescope, these galaxies appear to be physically associated and may be interacting. One galaxy shows signs of an active galactic nucleus, shown here as twin jets streaming out from a central black hole. David A. Aguilar (CfA)
In the distant reaches of the universe, almost 13 billion light-years from Earth, a strange species of galaxy lay hidden. Cloaked in dust and dimmed by the intervening distance, even the Hubble Space Telescope couldn’t spy it. It took the revealing power of NASA’s Spitzer Space Telescope to uncover not one, but four remarkably red galaxies. And while astronomers can describe the members of this new “species,” they can’t explain what makes them so ruddy.

“We’ve had to go to extremes to get the models to match our observations,” said Jiasheng Huang from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts.

Spitzer succeeded where Hubble failed because Spitzer is sensitive to infrared light — light so red that it lies beyond the visible part of the spectrum. The newfound galaxies are more than 60 times brighter in the infrared than they are at the reddest colors Hubble can detect.

Galaxies can be very red for several reasons. They might be very dusty. They might contain many old red stars. Or they might be very distant, in which case the expansion of the universe stretches their light to longer wavelengths and hence redder colors — a process known as redshifting. All three reasons seem to apply to the newfound galaxies.

All four galaxies are grouped near each other and appear to be physically associated, rather than being a chance line-up. Due to their great distance, we see them as they were only a billion years after the Big Bang — an era when the first galaxies formed.

“Hubble has shown us some of the first protogalaxies that formed, but nothing that looks like this,” said Giovanni Fazio from the CfA. “In a sense, these galaxies might be a ‘missing link’ in galactic evolution.”

Next, researchers hope to measure an accurate redshift for the galaxies, which will require more powerful instruments like the Large Millimeter Telescope or Atacama Large Millimeter Array. They also plan to search for more examples of this new “species” of extremely red galaxies.

“There’s evidence for others in other regions of the sky. We’ll analyze more Spitzer and Hubble observations to track them down,” said Fazio.

In the distant reaches of the universe, almost 13 billion light-years from Earth, a strange species of galaxy lay hidden. Cloaked in dust and dimmed by the intervening distance, even the Hubble Space Telescope couldn’t spy it. It took the revealing power of NASA’s Spitzer Space Telescope to uncover not one, but four remarkably red galaxies. And while astronomers can describe the members of this new “species,” they can’t explain what makes them so ruddy.

“We’ve had to go to extremes to get the models to match our observations,” said Jiasheng Huang from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts.

Spitzer succeeded where Hubble failed because Spitzer is sensitive to infrared light — light so red that it lies beyond the visible part of the spectrum. The newfound galaxies are more than 60 times brighter in the infrared than they are at the reddest colors Hubble can detect.

Galaxies can be very red for several reasons. They might be very dusty. They might contain many old red stars. Or they might be very distant, in which case the expansion of the universe stretches their light to longer wavelengths and hence redder colors — a process known as redshifting. All three reasons seem to apply to the newfound galaxies.

All four galaxies are grouped near each other and appear to be physically associated, rather than being a chance line-up. Due to their great distance, we see them as they were only a billion years after the Big Bang — an era when the first galaxies formed.

“Hubble has shown us some of the first protogalaxies that formed, but nothing that looks like this,” said Giovanni Fazio from the CfA. “In a sense, these galaxies might be a ‘missing link’ in galactic evolution.”

Next, researchers hope to measure an accurate redshift for the galaxies, which will require more powerful instruments like the Large Millimeter Telescope or Atacama Large Millimeter Array. They also plan to search for more examples of this new “species” of extremely red galaxies.

“There’s evidence for others in other regions of the sky. We’ll analyze more Spitzer and Hubble observations to track them down,” said Fazio.

0

JOIN THE DISCUSSION

Read and share your comments on this article
Comment on this article
Want to leave a comment?
Only registered members of Astronomy.com are allowed to comment on this article. Registration is FREE and only takes a couple minutes.

Login or Register now.
0 comments
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
BoxProductcovernov

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook

Loading...