California Institute of Technology | 2015 Aug 05
[imghover=http://s3-us-west-1.amazonaws.com/www-p ... WS-WEB.jpg]http://s3-us-west-1.amazonaws.com/www-p ... WS-WEB.jpg[/imghover][c]This picture combines a visible light image of the distant system with data from theA team of astronomers led by Caltech has discovered a giant swirling disk of gas 10 billion light-years away—a galaxy-in-the-making that is actively being fed cool primordial gas tracing back to the Big Bang. Using the Caltech-designed and -built Cosmic Web Imager (CWI) at Palomar Observatory, the researchers were able to image the protogalaxy and found that it is connected to a filament of the intergalactic medium, the cosmic web made of diffuse gas that crisscrosses between galaxies and extends throughout the universe.
Cosmic Web Imager (CWI). A filament of the cosmic web (outlined here with parallel
curved lines) can be seen funneling cold gas onto the protogalaxy (outlined with an
ellipse). The CWI is an integral field spectrograph; the researchers used it to create
a multiwavelength map showing the velocities with which gas in the system is moving
with respect to the center of the system. The red side of the disk is rotating away
from us, while the blue side is rotating toward us. Gas within the filament is moving
at a constant velocity that matches the blue side of the rotating disk.
(Credit: Martin/PCWI/Caltech)[/c][hr][/hr]
The finding provides the strongest observational support yet for what is known as the cold-flow model of galaxy formation. That model holds that in the early universe, relatively cool gas funneled down from the cosmic web directly into galaxies, fueling rapid star formation.
A paper describing the finding and how CWI made it possible currently appears online and will be published in the August 13 print issue of the journal Nature. ...
The protogalactic disk the team has identified is about 400,000 light-years across—about four times larger in diameter than our Milky Way. It is situated in a system dominated by two quasars, the closest of which, UM287, is positioned so that its emission is beamed like a flashlight, helping to illuminate the cosmic web filament feeding gas into the spiraling protogalaxy. ...
A giant protogalactic disk linked to the cosmic web - D. Christopher Martin et al
- Nature (online 05 Aug 2015) DOI: 10.1038/nature14616