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01101001
2007-Sep-06, 05:57 PM
JPL News Releaser: NASA Space Telescopes Find 'Lego-Block' Galaxies in Early Universe (http://www.jpl.nasa.gov/news/news.cfm?release=2007-097)


NASA's Hubble and Spitzer space telescopes have joined forces to discover nine of the smallest, faintest, most compact galaxies ever observed in the distant universe. Blazing with the brilliance of millions of stars, each of the newly discovered galaxies is 100 to 1,000 times smaller than our Milky Way galaxy.
[...]
The conventional model for galaxy evolution predicts that small galaxies in the early universe evolved into the massive galaxies of today by coalescing. These nine Lego-like "building block" galaxies initially detected by Hubble likely contributed to the construction of the universe as we know it.

Cute!

antoniseb
2007-Sep-06, 06:41 PM
I'm not sure how you could tell tiny bright galaxies from one big galaxy with several very bright star forming regions in it.

Swift
2007-Sep-06, 07:09 PM
Is this (http://www.hame.ca/blog2/pictures/497-1.1105158266.jpg) what you use to explore Lego-block galaxies? :D

Fortunate
2007-Sep-06, 07:25 PM
"Hubble detected sapphire blue stars residing within the nine pristine galaxies."

I'm surprised that they could identify individual stars at that distance.

Fortunate
2007-Sep-06, 11:06 PM
http://www.physorg.com/news108302681.html provides some complementary explanation.

"Blue light seen by Hubble shows the presence of young stars. The absence of red light from Spitzer observations conclusively shows that these are truly young galaxies without an earlier generation of stars."

Fortunate
2007-Sep-06, 11:14 PM
There is another thread on this topic in the Universe Today Stories forum.

01101001
2007-Sep-07, 12:26 AM
There is another thread on this topic in the Universe Today Stories forum.

As is almost always the case for a space/astronomy news story.

Fortunate
2007-Sep-07, 04:44 PM
http://www.physorg.com/news108302681.html provides some complementary explanation.

"Blue light seen by Hubble shows the presence of young stars. The absence of red light from Spitzer observations conclusively shows that these are truly young galaxies without an earlier generation of stars."

Why does "the absence of red light from Spitzer observations conclusively [show] that these are truly young galaxies without an earlier generation of stars"?

01101001
2007-Sep-07, 05:00 PM
Why does "the absence of red light from Spitzer observations conclusively [show] that these are truly young galaxies without an earlier generation of stars"?

Optical to mid-IR observations of Lyman-α galaxies at z≈5 in the HUDF: a young and low mass population (http://www.spitzer.caltech.edu/Media/releases/ssc2007-15/papers/pirzkal.pdf) (PDF)


[Conclusion:] The LAEs sources described in this paper are potentially the youngest and least massive galaxies observed to date and at a time when our Universe was just about ≈ 1Gyr old.

Fortunate
2007-Sep-07, 05:51 PM
01101001,

The link you provided took me to some data that I am not sophisticated enough to interpret. I was hoping to get a verbal explanation.