The Most Detailed 3-D Map of Local Universe Ever Created

[n2doc]

The Most Complete 3-D Map of Local Universe T.H. Jarrett (IPAC/SSC) via Harvard-Smithsonian Center for Atrophysics

Mapping the universe and its billions of galaxies is a tedious business, but a project spanning more than a decade and mashing up near-infrared sky surveys with painstaking redshift analysis has produced the wold’s most detailed 3-D map of the local universe. Reaching out to a distance some 380 million light-years from our own solar system, the 2MASS Redshift Survey (2MRS) was presented today at the 218th meeting of the American Astronomical Society.

The project mapped more than 43,000 galaxies picked from the Two-Micron All-SkySurvey (2MASS), which scanned the entire sky in three near-infrared wavelengths. But 2MASS alone offered an incomplete picture. To achieve the third dimension, astronomers needed to know not only how galaxies relate spatially on a flat map, but how far away they are from Earth and each other. So the 2MASS Redshift Survey began measuring the galaxies’ redshifts, one by one, using two telescopes in Arizona and Chile.

Redshifting is the way in which a galaxy’s light is stretched into longer wavelengths by the expansion of the universe. The farther a galaxy is from Earth, the greater its redshift. By analyzing those measurements, the 2MRS was able to achieve that important third dimension, and to produce the map you see above.

But 2MRS isn’t just notable for mapping faraway galaxies. It also made great strides closer to home. Regions nearer the Milky Way tend to be difficult to observe, as they are obscured by the dust and gas in our own galaxy. The near-infrared wavelengths employed by 2MASS are better at penetrating this dust, giving us a better look at our own galactic neighborhood.

http://www.popsci.com/technology/article/2011-05/most-detailed-3-d-map-local-universe-unveiled

[snagglepuss]

1. It's utterly staggering that those dots are galaxies. I initally assumed they were

stars.


FarManOut's comment at the link is interesting



"We are in the center. Imagine walking into the center of that image, grabbing the two edges and wrapping them in a circle around your head so the image forms a sphere around you.

I like this image better than the All-Sky full image of all the visible galaxies, which just has too many points to make any sense. You can almost see the structure here by looking at the colours as they shift from violet to dark red."


Thanks for posting.

[AlecBGreen]

2. to me, the REALLY amazing thing

is that these are only the galaxies within 380 million light years. The Universe is approximately 13 THOUSAND million light years across. How many more galaxies are out there? According to some back-of-the-napkin calculations, the actual universe has a volume 40,000X greater than what is shown here! :crazy:

[Hissyspit]

3. Yes, but...

What's out there beyond THAT?

[AlecBGreen]

4. according to my understanding

there is no 'edge' to the universe. It is akin to an ant crawling across a globe. The ant only knows 2 dimensions - forward/backward and side-to-side. He can travel infinitely in any direction yet never reach the edge of the globe. The universe is the same, though it has more than 2 dimensions.

I highly recommend this page: Ask An Astronomer @ Cornell. http://curious.astro.cornell.edu/ Lots of great info, divided into levels of difficulty (easy, medium, & difficult). Check it out! Very helpful!

[al bupp]

5. This is great, it just needs a little "you are here" sign /nt

[Occulus]

6. That would destroy your sanity

The Total Perspective Vortex is allegedly the most horrible torture device to which a sentient being can be subjected.

When you are put into the Vortex you are given just one momentary glimpse of the entire unimaginable infinity of creation, and somewhere in it a tiny little mark, a microscopic dot on a microscopic dot, which says, "You are here."

Located on Frogstar World B, the machine was originally invented by one Trin Tragula in order to annoy his wife. Because she was forever nagging him for having no sense of proportion, he decided to invent something that would show her what having a sense of proportion really meant. Unfortunately the shock of being placed in the Vortex destroyed her brain, but Trin Tragula's grief was tempered by the knowledge that he had been right and she had been wrong. In Adams's words, the Total Perspective Vortex illustrated that "In an infinite universe, the one thing sentient life cannot afford to have is a sense of proportion."