For 11 billion years after its formation through the Big Bang, the universe temperature was rising. This is the latest finding by an international team of scientists, led by researchers from Swinburne University of Technology.
They measured the temperature of the universe when it was 3 to 4 billion years old by studying the gas in between galaxies – the intergalactic medium. During these early years of the universe’s development, many extremely active galaxies were ‘switching on’ for the first time and heating their surroundings.
“However, 11 billion years ago, the universe began cooling down again,” said lead researcher Elisa Boera, from Swinburne’s Centre for Astrophysics and Supercomputing.
