Galaxies from the very early Universe

Two massive galaxies dance towards each other in this artist’s rendering. Credit: NRAO/AUI/NSF/D. Berry

Astronomy and astrophysics

A record-setting galaxy churns out stars

Hulking star system dates to the infant days of the Universe.

The biggest and brightest galaxy yet discovered in the far reaches of the Universe is sprouting stars at great speed.

Massive galaxies in their formative years are rarely spotted in the early Universe, because it takes extremely sensitive surveys of vast areas of the sky to find them. Daniel Marrone at the University of Arizona in Tucson and his colleagues studied infrared images taken by the Atacama Large Millimeter/submillimeter Array of a bright object dated to 780 million years after the Big Bang.

Previous observations suggested that the object was one gargantuan galaxy, but Marrone’s team found that it is a pair of galaxies in the process of merging. One of the galaxies is the biggest yet observed in this era of the Universe, producing enough new stars each year to equal 2,900 Suns in mass.

The object could be one of the largest and most distant galaxies in the early Universe, offering crucial insights into the formation of such objects, the authors say.