NASA | JPL-Caltech | Spitzer | WISE | 2015 Nov 03
[img3=" A Giant Gathering of Galaxies - Credit: NASA/JPL-Caltech/Gemini/CARMAAstronomers have discovered a giant gathering of galaxies in a very remote part of the universe, thanks to NASA's Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE). The galaxy cluster, located 8.5 billion light-years away, is the most massive structure yet found at such great distances.
The galaxy cluster called MOO J1142+1527 can be seen here as it existed when light left it 8.5 billion years ago. The red galaxies at the center of the image make up the heart of the galaxy cluster. "]http://www.spitzer.caltech.edu/uploaded ... 13_Med.jpg[/img3][hr][/hr]
Galaxy clusters are gravitationally bound groups of thousands of galaxies, which themselves each contain hundreds of billions of stars. The clusters grow bigger and bigger over time as they acquire new members.
How did these clusters evolve over time? What did they look like billions of years ago? To answer these questions, astronomers look back in time to our youthful universe. Because light takes time to reach us, we can see very distant objects as they were in the past. For example, we are seeing the newfound galaxy cluster -- called Massive Overdense Object (MOO) J1142+1527 -- as it existed 8.5 billion years ago, long before Earth formed.
As light from remote galaxies makes its way to us, it becomes stretched to longer, infrared wavelengths by the expansion of space. That's where WISE and Spitzer help out. ...
The Massive and Distant Clusters of WISE Survey: MOO J1142+1527,
a 1015 M⊙ Galaxy Cluster at z=1.19 - Anthony H. Gonzalez et al
- Astrophysical Journal Letters 812(2):L40 (2015 Oct 20) DOI: 10.1088/2041-8205/812/2/L40
arXiv.org > astro-ph > arXiv:1509.01989 > 07 Sep 2015