Wednesday, August 15, 2012

A Huge and Distant Cluster of Galaxies (and a Movie)



I want to introduce you to a short, but truly mind-boggling movie and then share a piece of news with you. 

All stars are organized into giant islands called galaxies. We live in one 
such island, called the Milky Way Galaxy, and our telescopes show many billions of other galaxies all around the sky. Like explorers on an unknown continent, we have recently been trying to map the way all these galaxies are distributed through space. Perhaps the most impressive such mapping project is called the Sloan Digital Sky Survey, and they just released a short film allowing you to fly through 400,000 galaxies whose positions in three-dimensional space have now been measured. Here is the movie: 
http://www.youtube.com/watch?v=08LBltePDZw 

Note that each little object on your screen is a galaxy of billions of stars (stars like the Sun)! Also note that the galaxies are not evenly distributed. Just like stars, they tend to be "social" -- they collect into groups (or galaxy clusters). 

Just today, astronomers announced the discovery of one of the largest galaxy clusters ever seen, nicknamed the Phoenix Cluster. It contains enough material (in many many galaxies) to make more than 2 million billion Suns. And it is almost 6 billion light years away, which means the light we see tonight from this huge grouping of galaxies left on its way to us before the Sun and the Earth ever existed. Wow. 


What makes the Phoenix cluster of special interest to astronomers is that, at its center, the gas falling in from all over the cluster is leading to a huge rash of newly forming stars. 740 new stars form in the middle galaxy of the cluster EVERY SINGLE YEAR. Many such galaxy cluster have a core that is "red and dead" -- with little star formation going on in the central galaxy. But this cluster has a center that's "blue and new" -- with lots of new stars being born. 

You can just stop there if (like many people) your head now hurts from the movie and the huge numbers I am throwing around. Just let the feeling of the immensity of the cosmos overtake you. (It helps a lot when you can't stand the pettiness of presidential politics these days.) Or, for more on the Phoenix Cluster see:

http://chandra.harvard.edu/press/12_releases/press_081512.html
or
http://www.skyandtelescope.com/news/Heavyweight-Cluster-166282866.html

1 comment:

  1. Besides of astrology, there would be hardly any section in the religious studies that receives lot of dissatisfaction. Is it not related to anything actually instead of misunderstood facts- natural sciences especially astronomy. This question may arise when we discuss astronomy.

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