Feeds

Finding missing galaxies: Spitzer triumphs again

No word on how they were lost

5 things you didn’t know about cloud backup

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. ®

Build a business case: developing custom apps

More from The Register

next story
Vulture 2 takes a battering in 100km/h test run
Still in one piece, but we're going to need MORE POWER
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
TRIANGULAR orbits will help Rosetta to get up close with Comet 67P
Probe will be just 10km from Space Duck in October
ANU boffins demo 'tractor beam' in water
The current state of the art, apparently
China to test recoverable moon orbiter
I'll have some rocks and a moon cheese pizza please, home delivery
What does a flashmob of 1,024 robots look like? Just like this
Sorry, Harvard, did you say kilobots or KILLER BOTS?
NASA's rock'n'roll shock: ROLLING STONE FOUND ON MARS
No sign of Ziggy Stardust and his band
Why your mum was WRONG about whiffy tattooed people
They're a future source of RENEWABLE ENERGY
Vulture 2 spaceplane autopilot brain surgery a total success
LOHAN slips into some sexy bespoke mission parameters
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.