Lyman Alpha Blob 1
LAB 1
Lyman alpha Blob 1 is the 5th largest nebula ever discovered in our universe. Lyman-alpha blob 1 (LAB-1) is located at the southern constellation of Aquarius, about 11.5 billion light-years away from Earth with a redshift (z) of 3.09. It is a giant cosmic cloud of hydrogen gas It was discovered suddenly in 2000 by Charles Steidel and team members,who were searching for high-redshift galaxies using the 200 inch (5.08 m) Hale telescope at the Palomar Observatory. The researchers had been investigating the plenty of galaxies in the young Universe when they came across two objects which would become known as Lyman-alpha blobs — vast concentrations of gases emitting the Lyman-alpha emission line of hydrogen.
Lyman Alpha Blob 1
Intergalactic Cloud
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Credit: Very Large Telescope, European Southern Observatory
Attribution : ESO / M. Hayes
Details..
Observation data
Subtype : Lyman Alpha Blob
Distance : 1.15 × 10^10 light years
Constellation : Aquarius
Physical Characteristics
Redius : 150,000 light years
LAB-1 is the first discovered Lyman-alpha blob (LAB), hence it has the number 1. It is the prototype of structure of this kind. It is also one of the largest of its kind, measuring 300,000 light years across, three times bigger than the Milky Way. The blob appears green on the picture because of the conjunction of the high redshift (z = 3) and the ultraviolet nature of the blob. Imaging with the European Southern Observatory's Very Large Telescope displayed that much of the light from the blob is polarized, the proportion increasing and peaking at about 20% at a radius of 45 kiloparsecs (145,000 light-years), forming a large ring around the blob.
Computer simulation of a lyman alpha blob
CC BY 4.0
Credit : J. Geach / D. Narayanan / R. Crain
It is still in dark as to why this object is emitting the Lyman-alpha emission radiation. It is thought that the light is coming from galaxies within the central area of the blob. Light of such power could be from active galaxies or supermassive black holes actively absorbing matter. An alternate theory is that the light is from cooling gas declining into early galaxies, which has probably come from cosmic filaments (as galaxies are thought to build at the intersections of these filaments), however the model of polarisation found argues against this.
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