Never-before-captured radio frequencies from thousands of universe have a secret to share: The height of star development in the cosmos may have been more fruitful than earlier imagined.
Radio telescopes are useful probes of star formation. But until now, they haven’t been delicate enough to see radio bands coming from the vast majority of galaxies that produced stars through the peak of star production, an epoch approximately 10 billion years ago known as cosmic midday.
A new from the MeerKAT observatory in South Africa has lifted the radio screen on those unsung galaxies. In that image, over 17,000 pinpoints of radio energy — nearly every one a star-forming galaxy — fill a gap of the sky that, as seen from Earth, could be coated by about five full moons.
Using about 10,000 well-studied close by galaxies as a template, James Condon and his colleagues measured how luminous and how far-off all those factors of light must be.
To match the observations, the radio frequencies must come from star-forming galaxies at cosmic midday beating out stars at about ten times the pace of modern constellations, says Condon, an astrophysicist at the National Radio Astronomy Observatory in Charlottesville.
There are a bit less than twice as many of these sources as anticipated, suggesting that star formation was much larger around cosmic midday than predicted by calculations based on infrared, optical, and ultraviolet data.