In new research, astronomers have underscored the reason behind the bright glow of the huge blobs of matter – called the Lyman-alpha blobs (Lab) - which are many times the size of a galaxy and were first discovered in the snapshots of the early universe.

Ever since the first observation of these blobs in the 1990s, several studies have revealed that these rare, ethereal objects were essentially gargantuan clouds of hydrogen gas and that they contained clusters of fledgling galaxies; but why they glow brightly still remained unexplained till now.

To find the reason behind the dazzle of the blobs, a team of astronomers recently turned the European Southern Observatory's Very Large Telescope in Paranal, Chile, to face the enormous Lyman alpha blob-1; and found that the light which the giant blob emitted was ‘polarized’ – that is, the electric and magnetic fields making up the lightwaves were aligned in a specific direction.

The astronomers – led by cosmologist Matthew Hayes, of the University of Toulouse – elaborated in the journal Nature that since the young galaxies inside Labs are birthplaces for stars, and the centres of some galaxies have extremely massive black holes, both these aspects apparently contribute to the heating up the gas cloud and causing the blobs to glow.

Noting that the polarization of light, as it is scattered through the gas cloud over distances of up to 150,000 light years, implies that the light comes from within the galaxies, Hayes said that the observation “helps us build a more accurate picture of how the universe formed.”