Secrets of Giant Space Blobs Discovered by ALMA

A team of astronomers using ALMA and the European Space Station's (ESO) Very Large Telescope discovered a rare object from a distant universe and it has many secrets.

The Lyman-alpha Blob is a rare gas cloud formation that is extremely bright. Thanks to the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers also discovered the secret of these blobs and two galaxies at the heart of one of the blobs that are currently undergoing a "frenzy" of stellar births causing a glow in its surroundings.

Interestingly, the large galaxies are surrounded by smaller clusters that make it appear that the blob is in the early stages of formation of massive clusters of galaxies. Astronomers describe newly discovered blobs or the Lyman-alpha Blobs (LABs) as gigantic gas clouds. They span up to thousands of light-years and are spotted in very distant parts of the universe. The name is also derived from the ultraviolet light emitting from the blobs called Lyman-alpha radiation.

For years, astronomers are mystified by the characteristics of blobs. But the recent discovery might have paved a way to finally understand the rare blobs better. SSA22-Lyman-alpha Blob 1 or LAB-1 is one of the most studied among its kind. LAB-1 was discovered in 2000, located at about 11.5 billion light-years away from Earth.

ALMA's "unparalleled" abilities to study, observe and analyze light coming from cool dust clouds in distant regions were used by a team of astronomers led by Jim Geach of the Center for Astrophysics Research of the University if Hertfordshire to analyze LAB-1 deeply. With ALMA, the astronomers were able to identify certain sources of emissions coming from the blob.

To further support the data, the astronomers included the image gathered by the Multi Unit Spectroscopic Explorer (MUSE) mounted to ESO's VLT. With the combined data, it was discovered that sources of emissions are the located at the heart of the blob where stars form over 100 times faster that Milky Way.

Furthermore, NASA/ESA's Hubble Space Telescope and the spectroscopy from the W. M. Keck Observatory showed that fainter galaxies also surround the sources. These companion galaxies could also be bombarding ALMA with materials that help the stellar formation rise.

"For a long time, the origin of the extended Lyman-alpha light has been controversial. Jim Geach, team lead of the study said in a press release. But with the combination of new observations and cutting-edge simulations, we think we have solved a 15-year-old mystery: Lyman-alpha Blob-1 is the site of formation of a massive elliptical galaxy that will one day be the heart of a giant cluster," Geach added.

The team also conducted complex simulations to visually demonstrate the rare glowing blob and its emissions.