Cosmic Dawn Ended 1.1 Billion Years After the Big Bang - Universe Today spacewriter
With stars you get heat—or, to be more scientifically correct—ionization. That happened when ultraviolet light from those hot, young massive stars tore apart the atoms of hydrogen and separate electrons from the protons. The good news is, that when you have ionization, you have light. And that, folks, is the executive summary of how the Universe lit up only a few hundred million years after the Big Bang.
To find out, they sifted through the light streaming from 67 distant quasars. Some of the light they looked at streamed from 25 quasars observed during a project called the. It used the European Southern Observatory’s X-shooter spectrograph installed on the Very Large Telescope in Chile. The X-shooter provides extremely high-resolution spectra of its targets. Spectra show the component wavelengths of light that a target emits or reflects.
The distance data let Bosman and colleagues make a precise measurement of the end of Cosmic Dawn. It happened at a point 1.1 billion years after the Big Bang. “I am fascinated by the idea of the different phases which the Universe went through leading to the formation of the Sun and Earth. It is a great privilege to contribute a new small piece to our knowledge of cosmic history,” she said.