Astronomers use observations of a gravitationally lensed galaxy to measure the properties of the early universe
http://phys.org/news/2016-10-astronomers-gravitationally-lensed-galaxy-properties.html
Although the universe started out with a bang it quickly evolved to a relatively cool, dark place.
After a few hundred thousand years the lights came back on and scientists are still trying to figure out why.
Astronomers know that reionization made the universe transparent by allowing light from distant galaxies to travel almost freely through the cosmos to reach us.
However, astronomers don't fully understand the escape rate of ionizing photons from early galaxies. That escape rate is a crucial, but still a poorly constrained
value, meaning there are a wide range of upper and lower limits in the models developed by astronomers.
That limitation is in part due to the fact that astronomers have been limited to indirect methods of observation of ionizing photons, meaning they may only see
a few pixels of the object and then make assumptions about unseen aspects. Direct detection, or directly observing an object such as a galaxy with a telescope,
would provide a much better estimate of their escape rate.
In a just-published paper, a team of researchers, led by a University of California, Riverside graduate student, used a direct detection method and found
the previously used constraints have been overestimated by five times.