| Description: | Astronomers can use the finite speed of light to look back in time. A recent upgrade at the Jansky Very Large Array in the USA has made it possible to observe at wavelengths that show the gas in galaxies when they were still young. The picture above show the molecular gas distribution (top) and velocity field (bottom) of a so-called Submillimeter-luminous galaxy (SMG) at a redshift of 4.05, or only 1.6 billion years after the Big Bang. SMGs are forming stars at an extremely rapid rate (1000 Msun/year) and are thought to evolve into the giant ellipticals we see in the local universe. Erwin de Blok (ASTRON), as part of a research team led by Jacqueline Hodge from the MPIA in Heidelberg, has modeled the dynamics of this galaxy, called GN20, and shows that it is consistent with that of a massive rotating disk, implying that gas disks could already have formed early in the universe. This work will soon be published in The Astrophysical Journal, but is already available at http://arxiv.org/abs/1209.2418 |
