Galaxy leaking high energy radiation may provide clues to reionization epoch

Los Angeles Times : The reionization epoch is the stage in the formation of the universe when the hydrogen atoms filling space were ionized and the universe became transparent to low-energy light. To achieve that ionization, highly energetic radiation was necessary, but where it came from is uncertain. One possibility is that early galaxies released large amounts of radiation in the extreme UV or higher—a range known as Lyman continuum radiation. However, galaxies trap most of the radiation in that range, with only a very few leaking as much 2% of the extremely high-energy radiation they produce. To initiate the reionization process, it is estimated that the early galaxies would have needed to release at least 20% of their extreme radiation. Now, researchers using the Hubble Space Telescope have found a galaxy that is leaking 21% of the radiation it produces in the Lyman continuum radiation. The galaxy, J0921+4509, is producing new stars at a massive rate of 50 solar masses per year, an order of magnitude greater than that of the Milky Way. It is possible that this rate of star creation is related to the amount of radiation escaping.