https://www.universetoday.com/14620...discovered-in-the-early-universe/#more-146206 A Massive Rotating Disc Discovered in the Early Universe If we want to understand how the Universe evolves, we have to understand how its large structures form and evolve. That’s why astronomers study galaxy formation. Galaxies are enormous structures of stars, planets, gas, dust, and dark matter, and understanding how they form is critical to understanding the Universe itself. In 2017, astronomers working with ALMA (Atacama Large Millimeter/sub-millimeter Array) discovered an ancient galaxy. This massive rotating disk galaxy was born when the Universe was only about 1.5 billion years old. According to the most accepted understanding of how galaxies form and evolve, it shouldn’t exist. But there it is. The galaxy is known as DLA0817g, but it’s much easier-to-remember nickname is Wolfe’s galaxy, named after the late astronomer Arthur M. Wolfe. It’s the most ancient rotating disk galaxy astronomers have ever seen. By only 1.5 billion years after the Big Bang, Wolfe’s galaxy grew to 70 billion solar masses, about half as massive as the Milky Way. There’s been some theoretical evidence that this type of galaxy might have existed this early in the Universe, but this is the first direct observational evidence. A new study titled “A cold, massive, rotating disk galaxy 1.5 billion years after the Big Bang” presents these observations. Lead author of the study is Marcel Neeleman of the Max Planck Institute for Astronomy in Heidelberg, Germany. The paper is published in the journal Nature. The Universe is about 13.8 billion years old. At first, it was just a hot, featureless plasma of electrons and protons, uniform in every direction. The challenge for cosmologists is to explain how all of that featureless mass combined into galaxies. Please Register or Log in to view the hidden image! The early Universe was an undifferentitated plasma, too hot for normal matter to coalesce and form structures like galaxies. Credit: Planck/IPAC more at link...................
the paper: https://www.nature.com/articles/s41586-020-2276-y?draft=marketing A cold, massive, rotating disk galaxy 1.5 billion years after the Big Bang: Abstract Massive disk galaxies like the Milky Way are expected to form at late times in traditional models of galaxy formation1,2, but recent numerical simulations suggest that such galaxies could form as early as a billion years after the Big Bang through the accretion of cold material and mergers3,4. Observationally, it has been difficult to identify disk galaxies in emission at high redshift5,6 in order to discern between competing models of galaxy formation. Here we report imaging, with a resolution of about 1.3 kiloparsecs, of the 158-micrometre emission line from singly ionized carbon, the far-infrared dust continuum and the near-ultraviolet continuum emission from a galaxy at a redshift of 4.2603, identified by detecting its absorption of quasar light. These observations show that the emission arises from gas inside a cold, dusty, rotating disk with a rotational velocity of about 272 kilometres per second. The detection of emission from carbon monoxide in the galaxy yields a molecular mass that is consistent with the estimate from the ionized carbon emission of about 72 billion solar masses. The existence of such a massive, rotationally supported, cold disk galaxy when the Universe was only 1.5 billion years old favours formation through either cold-mode accretion or mergers, although its large rotational velocity and large content of cold gas remain challenging to reproduce with most numerical simulations7,8
