Two young galaxies’ activity responsible for Lyman-alpha blobs’ glow: Study

Lyman-alpha blobs (LAB) are considered to be one of the most mysterious objects in the universe. Since they have been discovered in 2000, scientists have wondered what makes LAB to shine so brightly. In a latest research, astronomers have tried to peer inside Lyman-alpha blob 1, the original discovery.

These glowing clouds of hydrogen gas located 11.5 billion light years from earth were named LABs because of the specific wavelength of light that comes from them. The researchers have gone to the Atacama Large Millimeter/Submillimeter Array (ALMA) for the study.

From the observation, they have come to know that the blob comprises of two young galaxies that generate new stars. It is the activity carried out by them that light the cloud of gas present around them results into the blob's glow.

The two galaxies present at the center of the Lyman-alpha blob have been ejecting at least 100 sun-size stars per year, but later, most probably they will merge into a single, elliptical galaxy. Study’s co-author Dave Clements said that they are able to see just a snapshot of the galaxy 11.5 billion years ago.

Study’s lead researcher Jim Geach from the University of Hertfordshire said, “You see the diffuse glow because light is scattering off the tiny water droplets. A similar thing is happening here, except the streetlight is an intensely star-forming galaxy and the fog is a huge cloud of intergalactic gas. The galaxies are illuminating their surroundings”.

The findings can prove quite beneficial for astronomers when it comes to have a better understanding of how galaxies form and evolve. The research paper has provided an opportunity to see how young, growing galaxies have behaved when the universe was quite young, said Desika Narayanan from Haverford College in Pennsylvania.