Researchers have found a large population of distant dwarf galaxies that could reveal important details about a productive period of star formation in the universe billions of years ago. It is believed that dwarf galaxies played a significant role during the so-called reionisation era in transforming the dark early universe into one that is bright, ionised and transparent.
A new study comprised of 7,000 galaxies casts light on how young, hot stars ionise oxygen in the early universe and the effects on the evolution of galaxies through time. The study presents the first measurements of the changing strengths of oxygen emission lines from the present day and back to 12.5 billion years ago.
Astronomers have made the first accurate measurement of the abundance of oxygen in a distant galaxy. Oxygen is created inside stars and released into interstellar gas when stars die. Quantifying the amount of oxygen, the third-most abundant chemical element in the universe, is key to understanding how matter cycles in and out of galaxies.
EGSY8p7 is the most distant confirmed galaxy whose spectrum obtained with the W. M. Keck Observatory places it at a redshift of 8.68, at a time when the universe was less than 600 million years old. Hydrogen emission from EGSY8p7 may indicate it is the first known example of an early generation of young galaxies emitting unusually strong radiation.
Astronomers have spotted a super-sized black hole in the early universe that grew much faster than its host galaxy. The discovery challenges previous notions about the way host galaxies grow in relation to black holes and casts doubt on earlier suggestions that the radiation emitted by expanding black holes curtails the creation of stars.
An international team of astronomers has pushed back the cosmic frontier of galaxy exploration to a time when the universe was only 5 percent of its present age with the discovery of an exceptionally luminous galaxy more than 13 billion light-years from Earth. The galaxy existed so long ago, it appears to be only 100 million years old.