TFNR - Cosmic megastructures
Cosmic megastructures are the largest known formations in the universe, spanning billions of light-years and shaping the large-scale structure of the cosmos. These immense structures are composed of galaxies, galaxy clusters, and dark matter, forming a vast cosmic web.
Formazioni che emergono dalle interazioni gravitazionali tra galassie, soprattutto tra le componenti oscure di Materia ed Energia - formando una rete cosmica di filamenti, ammassi e vuoti.
ella loro forma più ampia, le galassie, rappresentano vaste formazioni interconnesse che modellano l'universo su scale molto grandi.
Examples of Cosmic Megastructures Hercules–Corona Borealis Great Wall – One of the largest known structures, spanning 9.7–10 billion light-years. It was discovered through gamma-ray burst mapping and remains a subject of debate.
Giant GRB Ring – A massive ring-shaped structure, approximately 5.6 billion light-years across. It challenges existing cosmological theories.
Huge-LQG (Large Quasar Group) – A collection of 73 quasars, extending 4 billion light-years.
Sloan Great Wall – A vast filament of galaxies, stretching 1.38 billion light-years.
South Pole Wall – A contiguous feature in the local universe, comparable in size to the Sloan Great Wall.
Quipu Superstructure – The largest cosmic superstructure ever observed, spanning over 400 megaparsecs (approximately 1.3 billion light-years) and containing an immense network of galaxy clusters.
Significance of Cosmic Megastructures These structures challenge our understanding of the universe’s large-scale organization. Some, like the Big Ring, defy conventional cosmological models, suggesting that the universe may not be as homogeneous as previously thought. Their discovery raises questions about the formation and evolution of cosmic structures, potentially requiring new theoretical frameworks.
Cosmic megastructures can be classified based on their scale, composition, and formation processes. Here’s a structured classification:
1. Galactic Megastructures Galaxy Groups – Small collections of galaxies bound by gravity (e.g., the Local Group).
Galaxy Clusters – Larger assemblies of hundreds to thousands of galaxies (e.g., the Coma Cluster).
Superclusters – Massive groupings of galaxy clusters (e.g., the Laniakea Supercluster).
2. Large-Scale Cosmic Structures Cosmic Filaments – Thread-like structures connecting galaxy clusters, forming the cosmic web.
Galactic Walls – Vast sheets of galaxies, such as the Sloan Great Wall and South Pole Wall.
Voids – Enormous empty regions with very few galaxies, like the Bootes Void.
3. Extreme Megastructures Large Quasar Groups (LQGs) – Massive quasar formations, such as the Huge-LQG.
Gamma-Ray Burst Structures – Enormous formations detected via gamma-ray bursts, like the Hercules–Corona Borealis Great Wall.
Supervoids – Exceptionally large voids, such as the Cold Spot Supervoid.
These structures define the universe’s large-scale organization, influencing cosmic evolution and matter distribution
Large Quasar Groups (LQGs) are some of the largest known structures in the universe, consisting of vast collections of quasars—extremely luminous active galactic nuclei powered by supermassive black holes. These structures challenge conventional cosmological models due to their immense size.
Characteristics of LQGs Composition – LQGs are made up of multiple quasars, which are regions of intense radiation surrounding supermassive black holes.
Scale – They span hundreds of megaparsecs, making them among the largest cosmic formations.
Cosmological Significance – Their existence raises questions about the homogeneity of the universe, as structures of this scale were once thought to be theoretically impossible.
The Huge-LQG Discovery – Announced in 2013 by researchers at the University of Central Lancashire.
Size – Spans approximately 4 billion light-years, making it one of the largest known structures at the time.
Quasar Count – Contains 73 quasars, forming a massive interconnected region.
Cosmological Implications – Its size exceeds the expected limits of cosmic structures, challenging the cosmological principle, which suggests that the universe should be homogeneous at sufficiently large scales2.
LQGs are thought to be precursors to the large-scale structures we see today, such as galaxy filaments and walls. Their discovery continues to push the boundaries of astrophysical research.
Common def
List
Giant Voids
Cosmic Web
Links to the tables of contents of TFNR Paper
