Lyman-alpha blob 1 (LAB-1) is a giant cosmic cloud of gas located at the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Aquarius Aquarius may refer to: Astrology * Aquarius (astrology), an astrological sign * Age of Aquarius, a time period in the cycle of astrological ages Astronomy * Aquarius (constellation) * Aquarius in Chinese astronomy Arts and entertainment ...

, approximately 11.5 billion light-years from Earth with a

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

(z) of 3.09. It was discovered unexpectedly in 2000 by Charles Steidel and colleagues, who were surveying for high-

galaxies using the 200 inch (5.08 m)

Hale telescope The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, de ...

at the

Palomar Observatory Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

. The researchers had been investigating the abundance of galaxies in the young Universe when they came across two objects which would become known as

Lyman-alpha blob In astronomy, a Lyman-alpha blob (LAB) is a huge concentration of a gas emitting the Lyman-alpha emission line. LABs are some of the largest known individual objects in the Universe. Some of these gaseous structures are more than 400,000 light ...

s—huge concentrations of gases emitting the Lyman-alpha emission line of hydrogen. LAB-1 is the first discovered Lyman-alpha blob, hence it has the number 1. It is the prototype of objects of this kind. It is also one of the largest of its kind, measuring 300,000 light years across, three times larger than the Milky Way. The blob appears green on the image because of the combination of the high redshift ( z = 3) and the ultraviolet nature of the blob. Imaging with the European Southern Observatory's Very Large Telescope showed that much of the light from the blob is polarized, the proportion increasing and peaking at around 20% at a radius of 45 kiloparsecs (145,000 light-years), forming a huge ring around the blob. It is still unclear 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 region of the blob. Light of such intensities could be from active galaxies or supermassive black holes actively absorbing matter. An alternate theory is that the light is from cooling gas falling into early galaxies, which has possibly come from cosmic filaments (as galaxies are thought to form at the intersections of these filaments), however the pattern of polarisation found argues against this.

Gallery

Computer simulation of a Lyman-alpha Blob.jpg, Computer simulation of a Lyman-alpha Blob. Lyman Alpha Blob.jpg, ''Left:'' Lyman alpha blob-1 as seen in Lyman-alpha (yellow), infrared (red) and ultraviolet (blue). The round blue object at the upper left of the blob is a giant galaxy. ''Right:'' Artist's impression of how the blob may look like if viewed from relatively close. Lyman-alpha blob 1 (MUSE).jpg, Lyman-alpha blob 1 seen by ESO's VLT

MUSE In ancient Greek religion and mythology, the Muses ( grc, Μοῦσαι, Moûsai, el, Μούσες, Múses) are the inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the ...

References

{{DEFAULTSORT:Lyman-alpha blob 1 Lyman-alpha blobs Aquarius (constellation)