Making sense of the Universe’s brightest galaxies

Massive bursts of star formation such as those in this galaxy can set off a complex feedback that sustains star formation for a billion years. (credit: NASA)

The brightest galaxies in the Universe are known as submillimeter galaxies (SMGs). That’s because they were discovered using light with wavelengths longer than a microwave, below infra-red on the electromagnetic spectrum. While they're very bright at visible wavelengths, most of their output there is blocked out by dust.

SMGs existed in the early days of the Universe, a mere three billion years after the Big Bang, during an era called the Cosmic Noon. They were bright because they were producing stars at an incredible rate; more recently they've been producing debate among Earthly scientists.

Their star formation rate is so intense that it actually challenged conventional models of how galaxies form when these SMGs were first discovered a decade ago. The debate over the issue still hasn’t been totally settled, but a new paper provides some significant support for one of the competing hypotheses.