January 29, 2014: A certain class of massive galaxies in the early universe lived fast and died young. By "died" astronomers mean that the galaxies had completed building stars just 3 billion years after the big bang. By contrast, our 12-billion-year-old Milky Way galaxy continues making stars today. When star formation stops, the aging stellar population looks redder in the star-forming galaxies that are more bluish. The nickname for the essentially "burned-out" galaxies is "red and dead."
By combining the power of Hubble with infrared space-based telescopes and ground-based telescopes, astronomers have now solved a decade-long mystery as to how compact elliptical-shaped galaxies existed when the universe was so young. These "red and dead" galaxies have now been linked directly to an earlier population of dusty starburst galaxies. These objects voraciously used up available gas for star formation very quickly. Then they grew slowly through merging as the star formation in them was quenched, and they eventually became giant elliptical galaxies.See the rest:
Science Credit: NASA, ESA, S. Toft (Niels Bohr Institute), V. Smolcic (University of Zagreb), B. Magnelli (Argelander Institute for Astronomy), A. Karim (Argelander Institute for Astronomy and Durham University), A. Zirm (Niels Bohr Institute), M. Michalowski (University of Edinburgh and Universiteit Gent), P. Capak (California Institute of Technology), K. Sheth (National Radio Astronomy Observatory), K. Schawinski (ETH Zurich), J.-K. Krogager (Niels Bohr Institute and European Southern Observatory), S. Wuyts (Max Planck Institute for Extraterrestrial Physics), D. Sanders (University of Hawaii), A. Man (Niels Bohr Institute), D. Lutz (Max Planck Institute for Extraterrestrial Physics), J. Staguhn (NASA Goddard Space Flight Center and Johns Hopkins University), S. Berta (Max Planck Institute for Extraterrestrial Physics), H. McCracken (Institut d’Astrophysique de Paris), J. Krpan (University of Zagreb), D. Riechers (Cornell University and California Institute of Technology), and G. Brammer (European Southern Observatory and STScI)