What is this weird, glowing blob in space? Scientists now think they know
A huge cloud of gas spanning hundreds of thousands of light years emits a strange ‘glow’ - which has puzzled scientists ever since it was found.
Now researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) think they have unravelled the mystery of the ‘Lyman-alpha blob’.
Until now, astronomers wondered why these huge clouds of gas shined so brightly.
The answer, in this example at least, appears to be two galaxies at the heart of the blob - which are forming stars furiously, and ‘lighting up’ the gas around them.
This appears to be an early phase in the formation of a massive cluster of galaxies.
Researchers using ALMA peered deeply into one of the largest Lyman-alpha Blobs known, SSA22-Lyman-alpha blob 1, or LAB-1.
Embedded in the core of a huge cluster of galaxies in the early stages of formation, it was the very first such object to be discovered - in 2000 - and is located so far away that its light has taken about 11.5 billion years to reach us.
Jim Geach , from the Center for Astrophysics Research of the University of Hertfordshire, UK says, ‘Think of a streetlight on a foggy night - 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.’
