The fluctuations of the cosmic microwave background

Les fluctuations du fond diffus cosmologique

IN BRIEF Cosmic Microwave Background (CMB): fossil radiation of the universe Fluctuations: temperature differences, indicating anisotropies Blue regions: cooler, indicating areas of low energy Red regions: warmer, signaling areas of high energy Inflation: early period of the universe explaining certain fluctuations Measurements by satellites WMAP and Planck CMB reveals characteristic B modes Temperature dipole: origin … Read more

The great discoveries of the Planck satellite

Les grandes découvertes du satellite Planck

IN BRIEF Satellite Planck launched in 2009 by the European Space Agency. Objective: to map the anisotropies of the cosmic radiation. Discovery of a supercluster of galaxies through its imprint on the cosmic background radiation. Analysis of the cosmic microwave background, light emitted 380,000 years after the Big Bang. Onboard instruments: Low Frequency Instrument (LFI) … Read more

The expansion of the universe: why and how

L'expansion de l'univers : pourquoi et comment

IN BRIEF Expansion of the Universe: phenomenon of galaxies moving away from each other. Observation by Edwin Hubble in 1929 on distance and redshift. Dynamic spaces: influence of gravity on space-time. Speed of expansion and its impact on cosmology. Origin of the Universe: about 13.8 billion years ago. Big Bang Theory and its implications for … Read more

The origin of solar winds and their impact

L'origine des vents solaires et leur impact

IN BRIEF Solar Wind: flow of particles ejected from the Sun. Origin: comes from the solar corona. Plasma: fills the heliosphere up to 100 astronomical units. Solar Storms: caused by clusters of sunspots. Earth’s Magnetic Field: protects Earth from ionized particles. Auroras: result from the interaction between solar wind and Earth’s atmosphere. Nuclear Reactions: source … Read more

Applied thermodynamics in astrophysics

La thermodynamique appliquée à l'astrophysique

IN BRIEF Thermodynamics: Study of physical properties as a function of temperature. Thermal equilibrium: State where temperature reaches a stable value. Astrophysics: Application of thermodynamic principles to astronomical phenomena. Wien’s Law: Principles used to analyze radiation in the universe. Mass-luminosity relation: Correlations between mass and light emission from stars. Understanding accretion disks and other astrophysical … Read more

Neutrinos and their importance in astrophysics

Les neutrinos et leur importance en astrophysique

IN BRIEF Neutrinos are nearly massless subatomic particles. They have no electric charge, making their identification complex. They act as messengers of cosmic phenomena. Neutrinos come from energetic events such as supernovae. They allow for a better understanding of astrophysical phenomena. These particles are more abundant than dark matter. Neutrino astronomy offers a complementary perspective … Read more

The physics of accretion disks around black holes

La physique des disques d'accrétion autour des trous noirs

IN BRIEF Black hole: a region of space with an intense gravitational field. Accretion disk: matter in orbit around a celestial body, often composed of gas and dust. Accretion disks around supermassive black holes: key to observing the accretion of matter. Inclination of the accretion disk and angle of observation influence the detected brightness. Emission … Read more

The properties of white dwarfs

Les propriétés des naines blanches

IN BRIEF Mass: between 0.3 and 1.4 times that of the Sun Volume: similar to that of the Earth Density: very high, resulting in intense gravitational forces Mass-size relation: the greater the mass, the smaller the size Electrons: exert a dominant quantum pressure within these celestial bodies Compactness: makes these celestial bodies sensitive to gravitational … Read more

Supercomputers at the Service of Astrophysics

Les superordinateurs au service de l’astrophysique

IN BRIEF Supercomputers: essential tools for research in astrophysics. Used for complex simulations of cosmic phenomena. Collaboration of researchers through supercomputers like Frontera and Jean Zay. Computational capacities exceeding quadrillions of operations per second. Ongoing projects to create the largest 3D map of the universe. Impact on the understanding of the evolution of the universe … Read more

The singularities in physics: what do they mean?

Les singularités en physique : que signifientelles ?

IN BRIEF Gravitational singularity: a region of spacetime where the laws of physics become imprecise. Involves mathematical limits according to the Einstein theory. References to the Penrose theorems and Hawking regarding black holes. Singularities are points where certain physical parameters reach infinity. The hidden singularity implies that physical laws break down. Interest in cosmology to … Read more