A trio of bubble-blowing galaxies may provide clues about one of the best cosmic makeovers in the history of the cosmos.
Someday during the universe’s first billion years, most of the hydrogen atoms in the universe turned ionized when their electrons were torn away.
Astronomers suspect that this reionization — so-called as all hydrogen had been previously ionized for the first few thousand years — was pushed by harsh ultraviolet light from the first creations of stars.
Researchers say they’ve caught a few galaxies emitting ionizing light and stripping electrons from neighboring hydrogen 680 million years after the Big Bang.
If so, this would be the first proof of a group of galaxies working collectively to ionize the early universe.
James Rhoads, the astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, offered the results on 5th January during a news conference at a gathering of the American Astronomical Society.
To look for ionizing galaxies, the group sought out galaxies in the distant cosmos, sending a particular wavelength of ultraviolet light.
Neutral hydrogen absorbs this wavelength, stopping it from reaching Earth; however, ionized hydrogen lets it slip by.
Utilizing the Mayall 4-meter telescope on Kitt Peak in Arizona, Rhoads and colleagues went looking for this light in a well-studied layer of the northern sky. They found three galaxies clustered together, shining with the light that took over 13 billion years to reach Earth.
While the brightest of these three galaxies was recognized to emit ionizing light, nobody had but observed that its neighbors did as well, says Brant Roberston, an astrophysicist at the College of California, who was not involved in this analysis.