Small, but plentiful: how the faintest galaxies illuminated the early universe

Astronomers investigating behaviour of the universe shortly after the Big Bang have made a surprising discovery: the properties of the early universe are determined by the smallest galaxies. The team report their findings in a paper published today in the journal Monthly Notices of the Royal Astronomical Society. A view of the entire simulation volume showing the large scale structure of the gas, which is distributed in filaments and clumps. The red regions are heated by UV light coming from the...