"The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have generated the variety of structures observed in nearby galaxies."
The processes of star formation, feedback, mergers, and interactions that shape the morphology and properties of galaxies.
Cosmology: The study of the origin, evolution, and structure of the universe, including the formation and evolution of galaxies.
The Big Bang: The theory explaining the origin of the universe, which started as a singularity and continues to expand today.
Dark Matter: An invisible substance that makes up a large portion of the universe's mass, yet its nature and composition remain unknown.
Dark Energy: A mysterious form of energy that causes the universe to expand at an accelerating rate.
The Hubble Space Telescope: A powerful telescope that has helped identify and study distant galaxies.
The Milky Way: Our own galaxy, consisting of more than 100 billion stars.
Galaxy Classification: The system used to categorize galaxies based on their morphology, including spiral, elliptical, and irregular.
Galaxy Formation: The process by which galaxies are created, including the role of dark matter in their formation.
Galaxy Evolution: The changes that occur in galaxies over time, including the growth of supermassive black holes in their centers.
Observational Cosmology: The measurement and analysis of data from telescopes and other astronomical instruments to understand the formation and evolution of galaxies.
The Cosmic Microwave Background: The radiation left over from the Big Bang, used to study the early universe.
Large-Scale Structure of the Universe: The distribution of galaxies and other matter on the largest scales, giving insight into the formation of the universe.
Supermassive Black Holes: Extremely dense objects found in the centers of galaxies, which play a significant role in their evolution.
Computer Simulations: Modeling the formation and evolution of galaxies using computer simulations.
Gravitational Lensing: The bending of light by massive objects, used to study distant galaxies and dark matter.
Gas and Dust in Galaxies: The properties and distribution of gas and dust within galaxies, which influence their formation and evolution.
Galaxy Clusters: Groups of galaxies held together by their mutual gravity, providing insight into the large-scale structure of the universe.
Star Formation and Stellar Populations: Understanding how stars form and how their properties change over time within galaxies.
Galaxy Interactions and Mergers: The impact of one galaxy on another, resulting in morphological changes in their structure.
Active Galactic Nuclei: The phenomenon of supermassive black holes affecting their environments, including quasars and other active galactic nuclei.
Primordial density fluctuations: This is the most widely accepted theory of galaxy formation. The fluctuations in the density of the universe shortly after the Big Bang led to the formation of structures such as galaxies.
Collisions and mergers: When galaxies collide and merge, they can form larger galaxies. This process also triggers the formation of new stars and can lead to the creation of supermassive black holes.
Accretion: Galaxies can grow through accretion, which is the process of absorbing gas and dust from the intergalactic medium. This gas can be used to form new stars and fuel the growth of black holes.
Halo or satellite accretion: When smaller galaxies are drawn into a larger galaxy's orbit, they become satellite galaxies. These satellite galaxies can then merge with the larger galaxy or be stripped of their gas and become "dead" galaxies.
Stellar feedback: The process of star formation can drive gas out of galaxies, limiting their growth. However, the energy and particles emitted from stars can also trigger the formation of new stars and drive the evolution of galaxies.
Filamentary structure: Galaxies can form within massive cosmic filaments, which are long chains of galaxies and intergalactic gas.
Cosmic web: Galaxies can be part of a larger cosmic web, which is a network of galaxy clusters and superclusters connected by cosmic filaments.
Freezing out: When the universe was very young and dense, the interactions between particles were intense enough to create new particles. As the universe cooled and expanded, these particle interactions became less frequent, leading to a "freeze-out" of the universe's physical properties. This freeze-out explains why the universe is the way it is today.
Quasar feedback: Supermassive black holes at the centers of galaxies can emit intense jets of energy and particles, which can either help or hinder star formation in the galaxy. When these jets become too powerful, they can shut down star formation completely, leading to the formation of "dead" galaxies.
Top-down formation: In this scenario, large structures such as superclusters of galaxies were formed first, and then galaxies formed inside these structures. This theory is less widely accepted than the primordial density fluctuations theory.
Bottom-up formation: This is the opposite of top-down formation. In this scenario, small structures such as individual galaxies were formed first, and then these galaxies merged and grew to form larger structures such as galaxy clusters and superclusters.
"Galaxy formation is hypothesized to occur from structure formation theories, as a result of tiny quantum fluctuations in the aftermath of the Big Bang."
"The simplest model in general agreement with observed phenomena is the Lambda-CDM model—that is, that clustering and merging allows galaxies to accumulate mass, determining both their shape and structure."
"Hydrodynamics simulation, which simulates both baryons and dark matter, is widely used to study galaxy formation and evolution."
"The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning."
"Galaxy formation is hypothesized to occur from structure formation theories, as a result of tiny quantum fluctuations in the aftermath of the Big Bang."
"The way galaxies change over time."
"Clustering and merging allows galaxies to accumulate mass, determining both their shape and structure."
"The processes that have generated the variety of structures observed in nearby galaxies."
"Clustering and merging allows galaxies to accumulate mass."
"The simplest model in general agreement with observed phenomena is the Lambda-CDM model."
"Hydrodynamics simulation, which simulates both baryons and dark matter."
"To study galaxy formation and evolution."
"Clustering and merging allows galaxies to accumulate mass."
"The formation of the first galaxies."
"The processes that have generated the variety of structures observed in nearby galaxies."
"Tiny quantum fluctuations in the aftermath of the Big Bang."
"The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning."
"Hydrodynamics simulation, which simulates both baryons and dark matter."
"Clustering and merging allows galaxies to accumulate mass."