Laniakea Supercluster

 "Universe Awareness Post."

Image and content: sourced from the Internet. 

What is the Laniakea Supercluster ?

The Laniakea Supercluster, is the large cosmic structure that contains our Milky Way galaxy. "Laniakea" is a Hawaiian name meaning "immense heaven". 

• Structure: It is a massive concentration of galaxies organized into a complex network of filaments.

• Size: It spans approximately 520 million light-years in diameter.

• Contents: It is home to roughly 100,000 large galaxies, grouped into hundreds of smaller clusters and groups.

• Location: The Milky Way galaxy is situated on its outskirts.

• Gravitational Center: Galaxies within Laniakea are gravitationally drawn toward a central region of high mass known as the Great Attractor, which lies near the Norma Cluster.

• Boundaries: The supercluster's boundaries are defined by the flow of galaxies, much like a watershed, where all internal motion converges toward the Great Attractor.

• Components: Key substructures within Laniakea include:

》 The Virgo Supercluster (which contains the Local Group and the Milky Way)

》 The Hydra–Centaurus Supercluster

》 The Pavo–Indus Supercluster

》 The Southern Supercluster 

The Laniakea Supercluster was first defined in 2014 by a team of astronomers who introduced a new method for mapping the universe's large-scale structures based on galaxy velocities. While it is a vast and significant structure, it is not gravitationally bound as a whole and is expected to eventually disperse due to the universe's ongoing expansion. 

The Norma cluster is the closest, most massive galaxy cluster to Earth and is a key part of the Great Attractor, located in the Zone of Avoidance  behind the Milky Way's center. Its importance is primarily in its role as a major gravitational center influencing our local universe, though observing it is difficult in visible light due to dust and stars from our own galaxy. Astronomers study it using X-rays and radio waves to map its structure, dynamics, and the role it plays in the motion of nearby galaxies. 

Key facts about the Norma cluster:

• Location: It is located in the Zone of Avoidance, a region behind the Milky Way's disk, making it very difficult to observe at optical wavelengths.

• Mass: It is the most massive cluster in the Great Attractor, with a dynamical mass estimated to be around estimated 10¹⁵ solar masses.

• Gravitational influence: The Norma cluster is a major gravitational center that influences the motion of nearby galaxies, including our own. It is sometimes considered part of the core of the Great Attractor.

• Observation challenges: Dust and stars in the Milky Way obscure the cluster, making it difficult to see in visible light.

• Methods of study: Astronomers use X-ray and radio telescopes, which can penetrate the dust, to study the cluster's structure and mass.

• Structure: It is a complex structure with both relaxed (elliptical galaxies) and substructured (spiral galaxies) components.

• Classification: It is classified as a rich, massive cluster, Abell 3627, and is considered an irregular (I) cluster. 

The Great Attractor is a region of intense gravitational pull in intergalactic space, located in the direction of the Centaurus constellation. It is not a single object, but a massive concentration of galaxies and other matter that exerts a strong gravitational force on the Milky Way and many other galaxies in our local supercluster. Because it is hidden behind the Milky Way's galactic plane and its dense dust clouds, it cannot be observed directly but its existence is inferred from its effect on the motion of nearby galaxies. 

• Nature: It is a gravitational anomaly, not a single object like a black hole. It's thought to be caused by the immense mass of the Laniakea Supercluster, of which the Milky Way is a part.

• Location: It is located in the direction of the Centaurus constellation, but its exact position is obscured by the Zone of Avoidance, a region of space filled with the dust and stars of our own Milky Way.

• Discovery: Astronomers discovered it in the 1970s and 1980s when they noticed that the motion of nearby galaxies, including the Milky Way, did not align with the expected expansion of the universe. Instead, these galaxies were all moving toward a specific point in space.

• Effect: The Great Attractor is pulling the Milky Way and about 100,000 other galaxies toward it at a speed of about 600 km/s. This journey will take billions of years and poses no immediate danger.

• Study: Astronomers can study the Great Attractor by observing the motions and velocities of galaxies beyond the Zone of Avoidance. They can also use infrared or radio telescopes to get a clearer view through the Milky Way's dust. 

Hi.... Do you still feel self-centred ? And do you want to go home ? Well, well, just don't forget to look above and look within !