National Radio Astronomy Observatory | 20016 Dec 01
[img3="Artist's conception of the Spiderweb. In this image, the protogalaxies are shown in white and pink, and the blue indicates the location of the carbon monoxide gas in which the protogalaxies are immersed.Astronomers studying a cluster of still-forming protogalaxies seen as they were more than 10 billion years ago have found that a giant galaxy in the center of the cluster is forming from a surprisingly-dense soup of molecular gas. ...
Modified from eso1431a; Credit: ESO/M. Kornmesser"]https://public.nrao.edu/images/pr/2016d ... a_nrao.jpg[/img3][hr][/hr]
The scientists studied an object called the Spiderweb Galaxy, which actually is not yet a single galaxy, but a clustering of protogalaxies more than 10 billion light-years from Earth. At that distance, the object is seen as it was when the Universe was only 3 billion years old. The astronomers used the Australia Telescope Compact Array (ATCA) and the National Science Foundation's Karl G. Jansky Very Large Array (VLA) to detect carbon monoxide (CO) gas.
The presence of the CO gas indicates a larger quantity of molecular hydrogen, which is much more difficult to detect. The astronomers estimated that the molecular gas totals more than 100 billion times the mass of the Sun. Not only is this quantity of gas surprising, they said, but the gas also must be unexpectedly cold, about minus-200 degrees Celsius. Such cold molecular gas is the raw material for new stars.
The CO in this gas indicates that it has been enriched by the supernova explosions of earlier generations of stars. The carbon and oxygen in the CO was formed in the cores of stars that later exploded. ...
Cool Theory on Galaxy Formation
Commonwealth Scientific and Industrial Research Organization | 2016 Dec 01
Giant galaxies may grow from cold gas that condenses as stars rather than forming in hot, violent mergers. ...
Molecular gas in the halo fuels the growth of a massive cluster galaxy at high redshift - B.H.C. Emonts et al
- Science 354(6316):1128 (02 Dec 2016) DOI: 10.1126/science.aag0512