Cosmic radiation gives us information about the Big Bang theory and the expansion of the universe.
Cosmic radiation is a highly energetic form of radiation that comes from outer space. These are cosmic rays composed mainly of protons, helium nuclei and other subatomic particles. They originate from various cosmic sources, such as supernovae, black holes, and other extreme astrophysical events. Upon reaching Earth, they interact with the atmosphere, producing a cascade of secondary particles that can be detected by instruments on the Earth's surface. Cosmic radiation is studied both for its impact on the atmosphere and technology, and for the information it provides about phenomena and conditions in the universe.
High energy particles
High-energy particles are subatomic particles that have extremely high energies , significantly higher than typical particles found under normal conditions on Earth. They can be protons, neutrons, electrons, as well as entire atomic nuclei and other subatomic particles. Its study is fundamental in fields such as particle physics , astrophysics and cosmology .
High-energy particles originate from various astrophysical and cosmological processes: cosmic rays, particle accelerators (such as hadron colliders ), and solar radiation. Some of its most important characteristics and effects are its high penetration, even of dense materials such as the Earth's atmosphere ; its ability to ionize atoms and molecules; its harmful biological effects on living organisms, including the possibility of damaging DNA and other cellular components.
Gamma rays, cosmic neutrinos, and cosmic rays are types of cosmic radiation.
Types of cosmic radiation
Cosmic radiation includes a variety of particles and forms of energy that reach Earth from outer space. Below we describe some of the main ones.
gamma rays
The most energetic form of electromagnetic radiation. They originate from extremely violent and energetic processes in the universe, such as supernova explosions, the nuclei of active galaxies, and the annihilation of matter and antimatter .
Gamma-ray astronomy is a branch of astronomy dedicated to the study of gamma-ray sources in the cosmos. Use space telescopes to detect and analyze this radiation. Its study helps us understand extreme astrophysical phenomena and the distribution of dark matter in the universe.
Cosmic neutrinos
Neutrinos are very light, neutral subatomic particles that interact weakly with matter, making them extremely difficult to detect. Cosmic neutrinos come from various sources, including the Sun, supernovae, and other high-energy cosmic events.
For its detection, there are neutrino observatories , such as the IceCube Neutrino Observatory in Antarctica. This uses a vast volume of transparent ice to capture the rare interactions of neutrinos with ice atoms.
Neutrino astronomy studies the sources and properties of cosmic neutrinos. Being able to traverse great distances without being deflected by magnetic fields, they provide direct information about nuclear processes inside stars and other astrophysical events.
Neutrino oscillation is a phenomenon that describes the change of one type of neutrino to another as they travel. It has been fundamental to understanding its behavior in the cosmos and particle physics. The cosmic neutrino background is a hypothetical background radiation composed of relict neutrinos from the Big Bang, similar to microwave background radiation . Although it has not yet been directly detected, its study could provide valuable information about the early universe.
Galactic and extragalactic cosmic rays
Cosmic rays are charged particles, mainly protons and atomic nuclei, that travel through space at speeds close to the speed of light. They are classified as galactic and extragalactic according to their origin.
Galactics come from our galaxy, the Milky Way, and originate mainly from energetic processes in the interstellar medium. By studying these rays, scientists can obtain information about the dynamics and composition of our galaxy. Extragalactics have their origin outside our galaxy, in even more energetic phenomena such as galaxy collisions. The detection and analysis of these rays allows us to explore the structure and evolution of the universe on a large scale.
Galactic atomic nuclei
In the context of cosmic rays, galactic atomic nuclei refer to the nuclei of heavy elements, such as iron and carbon, that are accelerated to high energies in astrophysical events. Their study provides information about the abundance of elements and nuclear processes in our galaxy.
Nuclear interactions can be weak or strong.
Interactions
Cosmic radiation and high-energy particles interact in various ways with magnetic fields and through weak and strong nuclear interactions. These are fundamental to understanding the behavior and propagation of these particles in space and their effects when they reach Earth.
Interaction of particles and magnetic fields
Charged particles, such as protons and atomic nuclei that make up cosmic rays, interact with magnetic fields present in space. These interactions influence its trajectory and energy.
Weak nuclear interactions
They are one of the four fundamental forces of nature. Unlike strong ones, they affect all subatomic particles, including neutrinos and quarks.
Neutrinos participate almost exclusively in weak interactions. In fact, they are so weak that neutrinos can pass through large amounts of matter without being stopped, making them difficult to detect. Weak interactions are also responsible for the neutrino oscillation phenomenon mentioned above.
Strong nuclear interactions
They are responsible for holding together the quarks within the protons and neutrons, and these nucleons within the atomic nucleus. It is the strongest of the four fundamental interactions, although it operates at extremely short distances.
Strong interactions play a crucial role in the production of cosmic rays . In high-energy events, such as particle collisions in accelerators, they can produce new subatomic particles and atomic nuclei that are ejected at high speeds. When high-energy cosmic rays hit the Earth's atmosphere, they interact strongly with the nuclei of atoms in the air, producing an atmospheric cascade of secondary particles.