Feeds

Finding missing galaxies: Spitzer triumphs again

No word on how they were lost

High performance access to file storage

NASA's Spitzer observatory has logged more than 1,000 previously unknown dwarf galaxies hiding out in a giant cluster of galaxies.

Using data from the infrared observatory, a team led by Leigh Jenkins and Ann Hornschemeier, both at NASA Space Flight Centre, was able to resolve many galaxies that are too faint for other telescopes to see.

Dwarf galaxies are thought to be the earliest stage of galactic evolution, and provide the building blocks for larger galaxies. Researchers also use them as tracers to track the larger scale structure of the universe.

The Coma cluster

But for all their usefulness, they have been remarkably thin on the ground. Simulations suggest we should find more of them in giant clusters, like the coma cluster, than have been seen to date.

The coma cluster, as it is known, lies 320 million light years away in the (surprise!) constellation Coma. It spans a volume approximately 20 million light years across, and holds hundreds of galaxies that have already been studied.

As a giant cluster it should be positively brimming with dwarf galaxies. And it seems it is. Of 30,000 objects logged by the research team, 1,200 were found (on closer examination) to be dwarf galaxies. Scaling up to take in the whole cluster, this implies at least 4,000 dwarf galaxies.

The team had initially thought that some of the fainter objects would be background galaxies even further away. But secondary data from the William Herschel telescope settled it: the faint smudges were small galaxies - with masses comparable to, or even smaller than, that of the Small Magellanic Cloud, one of the Milky Way's satellite galaxies.

"With Spitzer's superb capabilities, we have suddenly been able to detect thousands of faint galaxies that weren't seen before," says Jenkins.

"We're blowing away previous infrared surveys of nearby clusters," Hornschemeier notes. "Thanks to Spitzer, we can observe nearby clusters such as Coma very deeply in a short amount of time. The total observing time is comparable to just a few nights at a ground-based observatory."

The research is being presented at the American Astronomical Society meeting in Hawaii. The discovery paper will also appear in the Astrophysical Journal, NASA says. ®

High performance access to file storage

More from The Register

next story
Video games make you NASTY AND VIOLENT
Especially if you are bad at them and keep losing
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.