Source of Light for Massive Cosmic Blob Found

A team of astronomers was recently able to determine the origins of light emanating from the Lyman-alpha blob LAB-1. The cosmic structure has been puzzling astronomers for many years, and the new study is the first to propose a reasonable explanation for why the cosmic structure glows.

In order to investigate the object in detail, astronomers used the European Southern Observatory's (ESO) Very Large Telescope (VLT), at the Cerro Paranal Observatory, in Chile. The instrument was capable of analyzing the polarization of the light beams the blob was releasing.

Lyman-alpha blobs are extremely rare and bright gas clouds that are among the largest objects in the known Universe. They are mostly made up of hydrogen. In the case of LAB-1, experts say that it is lit up by numerous galaxies within it.

Blobs such as this one are widely considered to be remnants of a time when the Universe was a lot younger than it is today, Space reports. As such, understanding how they function is absolutely essential for making sense of how the earliest galaxies former.

“We have shown for the first time that the glow of this enigmatic object is scattered light from brilliant galaxies hidden within, rather than the gas throughout the cloud itself shining,” University of Toulouse investigator and lead study author Matthew Hayes explains, as quoted by Space.

Details of the new investigation were published in the August 18 issue of the top journal Nature. In the paper, the team explains that light polarization is a dead giveaway of the source that produced those specific wavelengths.

The challenge in analyzing Lyman-alpha blobs through traits such as light polarization is that the cosmic structures are billions of light-years away, which makes light measurements really difficult.

A ring around the central regions of LAB-1 was found to contain polarized light, but similar radiation were not discovered at the center of the cosmic structure. This implies that there are several light sources inside the blob, not just one.

Blobs can grow to sizes that dwarf the Milky Way's 120,000-light-year diameter, and enable them to release just as much energy as the brightest, most active galaxies. LAB-1, for example, is located some 11.5 billion years, and is the first blob ever discovered in space.

Astronomers have calculated that the structure contains one active galaxy, several primordial galaxies, and also that it is more than 300,000 light-years in diameter. The blob was discovered back in 2000.