A team of astronomers has reported that they have observed the most luminous galaxies ever seen in the Universe.
The objects are so bright that established descriptors, such as "ultra-" and "hyper-luminous," used to describe previously brightest known galaxies don't even come close.
Lead author Kevin Harrington said, "We've taken to calling them 'outrageously luminous' among ourselves, because there is no scientific term to apply."
Professor Min Yun, Harrington and colleagues used the latest generation of satellite telescope and a cosmology experiment on the NASA/ESA collaboration Planck satellite that detects the glow of the Big Bang and microwave background for this work. They estimate that the newly observed galaxies they identified are about 10 billion years old and were formed only about 4 billion years after the Big Bang.
Yun added that these galaxies were not predicted by theory to exist; they're too big and too bright, so no one really looked for them before. Discovering them will help astronomers understand more about the early Universe.
"Knowing that they really do exist and how much they have grown in the first 4 billion years since the Big Bang helps us estimate how much material was there for them to work with. Their existence teaches us about the process of collecting matter and of galaxy formation. They suggest that this process is more complex than many people thought," said Yun.
The researchers also pointed out that the newly observed galaxies are not as large as they appear.
The study appears in the Monthly Notices of the Royal Astronomical Society.
