One of the components of the general background cosm. email magn. radiation. R. i. uniformly distributed over the celestial sphere and corresponds in intensity to the thermal radiation of an absolutely black body at a temperature of approx. 3 K, discovered Amer. scientists A. Penzias and ... Physical Encyclopedia
RELICT radiation, filling the Universe with cosmic radiation, the spectrum of which is close to the spectrum of an absolutely black body with a temperature of about 3 K. It is observed at waves from several mm to tens of cm, almost isotropically. Origin... ... Modern Encyclopedia
Background cosmic radiation, the spectrum of which is close to the spectrum of a completely black body with a temperature of approx. 3 K. It is observed at waves from several mm to tens of cm, almost isotropically. The origin of relic radiation is associated with the evolution of ... Big Encyclopedic Dictionary
background radiation- Background cosmic radio emission, which was formed in the early stages of the development of the Universe. [GOST 25645.103 84] Subjects conditions physical space. space EN relic radiation … Technical Translator's Handbook
Background cosmic radiation, the spectrum of which is close to the spectrum of a black body with a temperature of about 3°K. It is observed at wavelengths from a few millimeters to tens of centimeters, almost isotropically. The origin of the relic radiation ... ... encyclopedic Dictionary
Electromagnetic radiation that fills the observable part of the Universe (See Universe). R. i. existed already in the early stages of the expansion of the Universe and played an important role in its evolution; is a unique source of information about her past... Great Soviet Encyclopedia
CMB radiation- (from lat. relicium remnant) cosmic electromagnetic radiation associated with the evolution of the Universe, which began its development after the "big bang"; background cosmic radiation, the spectrum of which is close to the spectrum of a completely black body with ... ... Beginnings of modern natural science
Background space radiation, the spectrum of which is close to the spectrum of an absolutely black body with a temperature of approx. 3 K. Observed on waves from several. mm to tens of cm, almost isotropically. R.'s origin and. associated with the evolution of the universe, to paradise in the past ... ... Natural science. encyclopedic Dictionary
Thermal background cosmic radiation, the spectrum of which is close to the spectrum of an absolutely black body with a temperature of 2.7 K. The origin of R. i. associated with the evolution of the Universe, which in the distant past had a high temperature and radiation density ... ... Astronomical dictionary
Cosmology Age of the Universe Big Bang Cosmic distance Relic radiation Cosmological equation of state Dark energy Hidden mass Friedmann Universe Cosmological principle Cosmological models Formation ... Wikipedia
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- A set of tables. Evolution of the Universe (12 tables), . Educational album of 12 sheets. Article - 5-8676-012. astronomical structures. Hubble law. Friedman model. Periods of evolution of the Universe. early universe. primary nucleosynthesis. Relic…
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MICROWAVE BACKGROUND
(relic radiation) - cosmic. radiation that has a spectrum characteristic of absolutely black body at temp. approx. 3 K; determines the intensity of the background radiation of the Universe in the range of centimeter, millimeter and submillimeter radio waves. It is characterized by the highest degree of isotropy (the intensity is almost the same in all directions). Opening M. f. and. [BUT. Penzias (A. Penzias), P. Wilson (R. Wilson), 1965] confirmed the so-called. hot universe theory, gave the most important experiment. evidence in favor of the concept of the isotropy of the expansion of the Universe and its homogeneity on large scales (see. Cosmology).
According to the theory of the hot Universe, the substance of the expanding Universe had a much higher density in the past than it does today and an extremely high temperature. At T> 10 8 K primary plasma, consisting of protons, helium ions and electrons, continuously emitting, scattering and absorbing photons, was in full thermodynamic. equilibrium with radiation. In the course of the subsequent expansion of the Universe, the rate of plasma and radiation fell. The interaction of particles with photons no longer had time to noticeably affect the emission spectrum during the characteristic expansion time ( optical thickness universe by bremsstrahlung by this time has become much less than unity). However, even in the complete absence of interaction between radiation and matter, during the expansion of the Universe, the black-body radiation spectrum remains black-body, only its rate decreases. While the temperature exceeded 4000 K, the primary substance was completely ionized, the range of photons from one scattering event to another was much less event horizon in the Universe. At T< 4000 К произошла рекомбинация протонов и электронов, плазма превратилась в смесь нейтральных атомов водорода и гелия. Вселенная стала полностью прозрачной для излучения. В ходе её дальнейшего расширения темп-pa излучения продолжала падать, но чернотельный характер излучения сохранился как реликт или "память" о раннем периоде эволюции мира. Это излучение было обнаружено сначала на волне 7,35 см, а затем и на др. волнах (от 0,6 мм до 50 см).
Temp-pa M. f. and. with an accuracy of 10% was equal to 2.7 K. Cp. the photon energy of this radiation is extremely small - 3000 times less than the photon energy of visible light, but the number of photons M. f. and. very large. For each atom in the Universe, there are ~ 10 9 photons M. f. and. (cf. 400-500 photons / cm 3).
Along with the direct method for determining the temperature of M. f. i. - according to the energy distribution curve in the radiation spectrum ( see Planck's radiation law) - there is also an indirect method - according to the population of the lower. energy levels of molecules in the interstellar medium. At absorption of a photon M. f. and. the molecule moves from the main state to excited. The higher the radiation rate, the higher the density of photons with energy sufficient to excite molecules, and the greater their fraction is at the excited level. According to the number of excited molecules (level populations), one can judge the temperature of the exciting radiation. Thus, the observations of optical absorption lines of interstellar cyanogen (CN) show that its lower. the energy levels are populated as if the CN molecules are in a three-degree black-body radiation field. This fact was established (but not fully understood) as early as 1941, long before the discovery of M. f. and. direct observations.
No stars and radio galaxies, no hot intergalaxies. gas, nor the re-emission of visible light by interstellar dust, can produce radiation approaching M. f. in properties. and.; the total energy of this radiation is too high, and its spectrum does not resemble either the spectrum of stars or the spectrum of radio sources (Fig. 1). This, as well as the almost complete absence of intensity fluctuations over the celestial sphere (small-scale angular fluctuations), proves the cosmological. relic origin M. f. and.
Rice. 1. Spectrum of microwave background radiation of the Universe [intensity in erg/(cm 2 *s*sr*Hz)]. Experiment. points are plotted with indication of measurement errors. The points CN, CH correspond to the results of determining the upper limit (shown by the arrow) of the radiation temperature from the level population of the corresponding interstellar molecules.
Fluctuations of M. f. and. Detection of small differences in the intensity of M. f. and., received from different parts of the celestial sphere, would allow us to draw a number of conclusions about the nature of the primary perturbations in matter, which subsequently led to the formation of galaxies and clusters of galaxies. Modern galaxies and their clusters were formed as a result of the growth of matter density inhomogeneities, insignificant in amplitude, that existed before the recombination of hydrogen in the Universe (see Fig. Primary fluctuations in the Universe). For any cosmological model, one can find the law of growth of the amplitude of inhomogeneities in the course of the expansion of the Universe. If you know what were the amplitudes of the inhomogeneity of the substance at the time of recombination, you can determine how long they could grow and become about unity. After that, regions with a density much higher than the average should have separated from the general expanding background and given rise to galaxies and their clusters (see Fig. Large-scale structure of the Universe). Only relic radiation can "tell" about the amplitude of the initial density inhomogeneities at the moment of recombination. Since, before recombination, radiation was rigidly bound to matter (electrons scattered photons), inhomogeneities in the spatial distribution of matter led to inhomogeneities in the radiation energy density, i.e., to a difference in radiation temperature in regions of the Universe with different density. When, after recombination, the substance ceased to interact with radiation and became transparent to it, M. f. and. was supposed to preserve all the information about density inhomogeneities in the Universe during the recombination period. If heterogeneities existed, then the pace-pa M. f. and. should fluctuate depending on the direction of observation. However, experiments to detect the expected fluctuations have not yet yielded measurable values. They make it possible to show only the top, the limits of fluctuation values. In small corners scales (from one arc minute to six degrees of arc) fluctuations do not exceed 10 -4 K. Searches for fluctuations M. f. and. are also complicated by the fact that the contribution to the background fluctuations is given by discrete cosmic. radio sources, the radiation of the Earth's atmosphere fluctuates, etc. Experiments at large angles. scales also showed that the temperature of M. f. and. practically does not depend on the direction of observation: deviations do not exceed 4 * 10 -3 K. The data obtained made it possible to reduce the estimate of the degree of anisotropy of the expansion of the Universe by a factor of 100 compared to the estimate from direct observations of "receding" galaxies.
M. f. and. as "new air". M. f. and. isotropic only in the coordinate system associated with "receding" galaxies, in the so-called. comoving frame of reference (this frame is expanding along with the Universe). In any other coordinate system, the radiation intensity depends on the direction. This fact opens up the possibility of measuring the speed of the Sun relative to the coordinate system associated with M. f. and. Indeed, due to affect doppler photons propagating towards a moving observer have a higher energy than those catching up with him, despite the fact that in the system associated with M. f. i.e., their energies are equal. Therefore, the radiation rate for such an observer turns out to depend on the direction: where is the average sky radiation rate, is the observer's speed, is the angle between the velocity vector and the direction of observation.
Rice. 2. Distribution of the brightness of the microwave background radiation on the celestial sphere. The numbers characterize the deviations from the average microwave background temperature over the entire sphere in mK.
The anisotropy of the relic radiation associated with the motion of the solar system relative to the field of this radiation has been firmly established by now (Fig. 2), it has a dipole character; in the direction of the constellation Leo temp-pa M. f. and. by 3.5 * 10 -3 K exceeds the average, and in the opposite direction (the constellation of Aquarius) by the same amount below the average. Consequently, the Sun (together with the Earth) moves relative to M. f. and. at a speed of approx. 400 km/s towards the constellation Leo. The accuracy of observations is so high that experimenters fix the speed of the Earth around the Sun, which is 30 km/s. Accounting for the speed of the Sun around the center of the Galaxy makes it possible to determine the speed of the Galaxy relative to M. f. and. It is km/s. In principle, there is a method that makes it possible to determine the velocities of rich galaxy clusters relative to the background radiation (see Fig. clusters of galaxies).
Spectrum M. f. and. On fig. 1 shows the existing experiments. data on M. f. and. and the Planck energy distribution curve in the equilibrium radiation spectrum of a blackbody with a temperature of Experiment. points are in good agreement with the theoretical curve, which is a strong confirmation of the model of the hot Universe.
Note that in the range of centimeter and decimeter waves, measurements of the temperature of M. f. and. possible from the surface of the earth. In the millimeter and especially in the submillimeter ranges, atmospheric radiation interferes with observations of M. f. and., therefore, measurements are carried out by broadband bolometers mounted on balloons (cylinders) and rockets. Valuable data on the spectrum of M. f. and. in the millimeter range obtained from observations of the absorption lines of molecules interstellar medium in the spectra of hot stars. It turned out that the main contribution to the energy density M. f. and. gives radiation with a wavelength of 6 to 0.6 mm, the temperature of which is close to 3 K. In this wavelength range, the energy density of M. f. i.eV/cm 3 .
One of the experiments to determine the fluctuations of M. f. and., its dipole component and the top, the boundaries of the quadrupole radiation was carried out on the satellite "Prognoz-9" (USSR, 1983). Angle the resolution of the equipment was approx. The registered thermal contrast did not exceed K.
Many of the cosmological theories and theories of galaxy formation, which consider the processes annihilation. matter and antimatter, dissipation of developed turbulence, large-scale potential movements, evaporation of primary black holes low mass, the decay of unstable elementary particles, then predict the release of energy in the early stages of the expansion of the universe. At the same time, any release of energy at the stage when the temperature M. f. and. changed from 3·10 8 K to 3 K, it should have noticeably distorted its black-body spectrum. T. o., spectrum M. f. and. carries information about the thermal history of the universe. Moreover, this information turns out to be differentiated: the release of energy at each of the three stages of expansion
Calls specific. spectrum distortion. At the first stage, the spectrum is most distorted in the LW region, at the second and third - in the short-wavelength region. The recombination process itself contributes to the distortion of the spectrum in the HF region. Photons emitted during recombination have an energy of approx. 10 eV, which is tens of times higher than cf. energy of photons of equilibrium radiation of that epoch (at K). There are very few such energetic photons (out of their total number). So recombinationradiation, arising during the formation of neutral atoms, should have strongly distorted the spectrum of M. f. and. on the waves
The substance of the Universe could experience another heating during the formation of galaxies. Spectrum M. f. Compton effect). Particularly strong changes occur in this case in the HF region of the spectrum. One of the curves demonstrating the possible distortion of the spectrum of M. f. i., shown in Fig. 1 (dashed curve). Available changes in the spectrum of M. f. and. showed that the secondary heating of matter in the Universe occurred much later than recombination.
photon increases many times, and the radio photon turns into an x-ray photon. radiation, while the energy of the electron changes insignificantly. Since this process is repeated many times, the electron gradually loses all the energy. Observed from satellites and rockets roentgen. the background radiation appears to be partly due to this process.
Protons and superhigh-energy nuclei are also affected by M.f. photons. and .: in collisions with them, the nuclei split, and collisions with protons lead to the birth of new particles (electrop-positron pairs, pions, etc.). As a result, the energy of protons rapidly decreases to a threshold value, below which the production of particles becomes impossible according to the laws of conservation of energy and momentum. It is with these processes that the practice is associated. absence in space beams of particles with energy 
as well as a small number of heavy nuclei.
Lit.: Zel'dovich Ya. B., "Hot Model" of the Universe, UFN, 1966, v. 89, p. 647; Weinberg S., The first three minutes, trans. from English, M., 1981. P. A. Sunyaev.
- - 1) the process of excitation of electromagnetic waves in the environment by oscillating charged particles; 2) electromagnetic waves themselves are also called radiation in the process of their propagation in a particular medium ...
The Beginnings of Modern Natural Science
BACKGROUND radiation in astrophysics is diffuse and practically isotropic electromagnetic radiation of the Universe. The spectrum of background radiation extends from long radio waves to gamma rays. A contribution to the background radiation can come from distant sources that are indistinguishable separately and diffuse matter (gas, dust) that fills outer space. The most important component of background radiation is relic radiation.
BACKGROUND RADIATION - radiation that is present in the environment under normal conditions. It should be taken into account when measuring radiation from any particular source.
CMB radiation
Relief radiation (or cosmic microwave background radiation from _en. cosmic microwave background radiation). The term "relic radiation", which is usually used in Russian-language literature, was introduced by the Soviet astrophysicist I.S. Shklovsky - cosmic electromagnetic radiation with a high degree of isotropy and with a spectrum characteristic of an absolutely black body with a temperature of 2.725 K.
The existence of the CMB was predicted theoretically within the framework of the Big Bang theory. Although many aspects of the original Big Bang theory have now been revised, the fundamentals that made it possible to predict the temperature of the CMB remain unchanged. It is believed that the relict radiation has been preserved from the initial stages of the existence of the Universe and evenly fills it. Its existence was experimentally confirmed in 1965. Along with the cosmological redshift, the CMB is regarded as one of the main confirmations of the Big Bang theory.
The nature of radiation
According to the Big Bang theory, the early Universe was a hot plasma consisting of photons, electrons and baryons. Thanks to the Compton effect, photons constantly interacted with the rest of the plasma particles, experiencing elastic collisions with them and exchanging energy. Thus, the radiation was in a state of thermal equilibrium with matter, and its spectrum corresponded to the spectrum of an absolutely black body.
As the Universe expanded, the cosmological redshift caused the plasma to cool and, at a certain stage, it became energetically preferable for electrons to form atoms by combining with protons - hydrogen nuclei and alpha particles - helium nuclei. This process is called recombination. This happened at a plasma temperature of about 3,000 K and an approximate age of the universe of 400,000 years. From that moment on, photons ceased to be scattered by now neutral atoms and were able to move freely in space, practically without interacting with matter. The observed sphere corresponding to a given moment is called the last scattering surface. It is the most distant object that can be observed in the electromagnetic spectrum.
Universe, not distorted by nearby sources (Earth's atmosphere, radiation from the Galaxy, etc.). It is F. to. and. would have to perceive devices with a wide field of view, taken out into the space between galaxies. Unfortunately, such an experiment is impossible. Astronomers study F. c. and., using ground-based and extra-atmospheric instruments. In this regard, the separation of the background component from the diffuse (scattered) radiation of the local and galactic. nature is a difficult task.
Often the background is called. all interferences that make it difficult to extract a signal from a discrete object: own. instrument noise, x-ray reports. counters caused by the presence of space. rays, diffuse radiation falling into the field of view of the instrument (in particular, it can also be F. to. and. when observing sources with small angular sizes), etc. It should be emphasized the difference between F. to. and. from the concept of the background in a certain sense.
F.'s research to. and. represents themselves. interest, because it carries information about the radiation that fills the entire Universe, i.e. information about the Universe as a whole. Besides, F. to. and. may contain the radiation of a large number of individually indistinguishable discrete sources and the measurement of F. to. and. gives some estimates of their properties.
Historically, the first problem associated with F. to. And., was the problem of the brightness of the night sky in the visible range. In connection with it, the simplest cosmological problem was formulated. test, which entered the history of science under the name. Olbers paradox, or photometric paradox: in an infinite homogeneous stationary Universe, on any line of sight, we must see the surface of a star, i.e., the entire sky must have a brightness comparable to the brightness of the solar disk. It is obvious that such a model of the Universe is in conflict with our everyday experience - the brightness of the night sky in the visible range is very low. Olbers' paradox is resolved in modern. evolutionary models of the universe. Galaxies were born ca. 10 billion years ago, the number of stars in the universe is so small that the cosmological. horizon ( ct~10 28 cm) the fraction of the sky covered by stars is negligible. In addition, the radiation of stars at large distances is shifted to the IR range due to redshift and does not contribute to the observed sky brightness in the visible range.
Accurate knowledge of the brightness of the night sky (more precisely, optical F.C.I., the intensity of which is at least a hundred times less than the brightness of the night sky, the main contribution to which is given by atmospheric glow, zodiacal light and light stars of the Galaxy) imposes severe restrictions on specific models of the evolution of galaxies, on the duration of the bright phase of their evolution at the stage of the "young galaxy", etc.
Astronomers are interested not only in the value of the brightness of the sky in a particular range of wavelengths e-magn. spectrum, but also ang. fluctuations in the background radiation intensity. In an isotropically expanding universe, the background radiation must be isotropic: its intensity must not depend on direction. The isotropy of the true background facilitates its separation from local sources of diffuse radiation. At the same time, if the main the source of the background is the radiation of discrete sources, then at very small angles. sizes, when in the field of view of the device falls into cf. order of one source, the background intensity should fluctuate strongly when moving from one area of observation in the sky to another. These fluctuations can be used to judge spaces. distribution of sources, as well as their distribution along the flow.
Analysis of the nature of F. to. and. shows that in most ranges of the spectrum, its intensity is determined by many. distant discrete sources of radiation. In a number of F.'s ranges to. and. not related to discrete sources. Its existence is either a property of the Universe as a whole (the so-called relic radiation), or a consequence of the presence in the intergalactic. space of the radiating substance (hot intergalactic gas, cosmic rays).
On fig. 1 and in table. data on measurements and estimates of the intensity of F. to. and.
Rice. 1. Spectrum of electromagnetic background radiation Universe. The solid line is the results of observations, the dashed line is the theoretical estimates; Iv in erg (cm 2. s. Hz. sr) -1.
Energy density and number of photons of background radiation in different ranges
Only in the optical and radio ranges of observation F. to. and. can be produced from the surface of the Earth. Research in UV, X-ray. and g-bands of the spectrum became possible only thanks to the success of extra-atmospheric astronomy.
F.'s allocation to. and. against the background of the radiation of the Galaxy turned out to be a difficult task. On fig. Figure 2 shows the relationship between the diffuse radiation of the Galaxy and the F. to. and.
radio band. L o n w o w o f r a d i o d i o n e ( v<600 МГц; l>50 cm). Radio telescopes receive both FCT and synchrotron radiation from relativistic electrons in the interstellar medium of the Galaxy, which makes it difficult to isolate FCT. Synchrotron radiation from the Galaxy is extremely unevenly distributed over the sky. Of interest is the area in the sky with min. brightness temperature T b equal to 80 K at a frequency of 178 MHz. It is clear that this is the top. limit on the brightness temperature F. to. and. at this frequency. Select extragalactic components is possible only if the emission spectrum of the Galaxy differs from the spectrum of the F. to. and. Unfortunately, they are close enough. Careful analysis shows that the background brightness temperature at a frequency of 178 MHz is close to 30 K, and the spectral index coincides with cf. spectral index of radiation radio galaxies a=0.75. This allows you to find the brightness temperature and the intensity of the F. to. and. at any wavelength in the meter range T b 30 (l/1.7m) 2.75 K, Iv= 3 . 10 -19. (l/1.7m) 0.75 erg (
see 2. s. Hz. cf) -1 . Coincidence of spectral indices F. to. and. and radio galaxies led to the assumption that long-wave F. to. and. represents the total radiation of distant powerful discrete sources of radio emission: radio galaxies and quasars. However, observed in the vicinity of our Galaxy of spaces. density of radio galaxies and their radio luminosity (see. Luminosity) turned out to be insufficient to explain the intensity of F. to. and. It was only after careful calculations of weak (and, therefore, distant) radio sources that it was possible to advance in resolving this issue. The dependence of the number of sources on the flux turned out to be much steeper than expected. This suggests that earlier, when the Universe was much younger, there were much more powerful radio sources than now (more precisely, there were more radio sources for a given number of galaxies). There was a cosmological evolution of radio sources. Distant powerful radio galaxies and quasars are observed today as weak radio sources. It turned out that these are the many sources define F. to. and. in the region of long radio waves.
Rice. 2. Ratio of the energy densities of the background radiation of the universe and diffuse radiation halactic origin; r in eV / cm 3.
infrared range(10 12 Hz< v<3 10 14 Гц; 1 мкм
The sensitivity of modern instrumentation is insufficient for non-intermediates. observations of infrared F. to. and. On fig. 1, 2 and the table shows the results of theoretical. estimates of the total radiation of quasars and galactic nuclei based on observational data on infrared radiation from individual sources and data on their density in the Universe. Visible Range<
1 µm). For allocation of visible F. to. and. from the observed diffuse radiation, it is necessary to subtract the radiation from relatively nearby sources: atmospheric emission, zodiacal light(the light of the Sun scattered on interplanetary dust), the integral light of the stars of the Galaxy. Atmospheric emission becomes insignificant for observations outside the Earth's atmosphere. In ground-based observations, to exclude it, a correction is introduced based on studies of the transmission of the atmosphere at different angles to the zenith. The contribution of the zodiacal light can, in principle, be taken into account by launching a cosmic devices perpendicular to the plane of the ecliptic at a distance of ~ 1 AU. i.e., to a region where there is practically no interplanetary dust. Another, now more accessible, way is to use models of the luminescence of zodiacal dust, as well as in observations of the visible F. to. and. in the Fraunhofer lines, where the solar radiation is weak and therefore the zodiacal light is weakened. Intensive studies are being carried out on the properties of zodiacal light from rockets and satellites with the aim of isolating the visible F. to. and. The third factor can be estimated from the function of luminosity and space. distribution of stars in the galaxy. This factor contributes Ch. uncertainty in the study of extragalactic. optical component. sky glow.
During observations from the Earth, no traces of the isotropic visible component of the F. to. and. Top. the limit turned out to be about 100 times less than the total observed sky brightness in the visible range. Knowing the emission spectrum galaxies, their density in space and distances to galaxies, it is possible to calculate their integral radiation. At the same time, it turns out that contribution to the visible F. to. and. give the rules. galaxies (more precisely, the radiation of their constituent stars).
It should also be taken into account that if the intergalactic space is filled with stars, clusters of stars or dwarf galaxies, they are almost impossible to detect with modern. the level of observation technology. In this regard, the contribution of these "luminous" objects to cf. the density of matter in the universe is unknown. Here the upper bounds turn out to be useful. limit of intensity F. to. and. in the visible range. If these invisible objects have the mass - luminosity ratio the same as for galaxies on average, then using the experiment. data, it can be shown that the mass of luminous bodies in the Universe is small for the Universe to be closed (see Fig. Cosmology).
UV range. This region of the spectrum can be conditionally divided into two parts: the first is available for observations from satellites and rockets, the second is fundamentally inaccessible for direct observations from the solar system.
Range available for observation. The brightness of the sky in the UV region of the spectrum is determined by the radiation of hot stars in our Galaxy. Obviously, the higher the temperature T surface of a star, the more photons it emits in the UV range. The number of stars with a given temperature decreases rapidly with increasing T. Therefore, the total radiation of the stars of the Galaxy also rapidly decreases with decreasing wavelength. So, according to measurements on space. stations "Venus", the integral luminosity of our Galaxy (excluding the unknown contribution of its core) in the band 1225-1340 is estimated at 10 40 -10 41 erg / s, which is only 10 -3 -10 -4 of its luminosity in the visible range. Therefore, it was expected that the selection of extragalactic component in the UV range will be lighter than in the visible, and that it will carry information in the main. about non-stellar sources - the nuclei of galaxies, quasars, intergalactic. gas. True, powerful radiation due to the re-emission of the line by interplanetary hydrogen also falls into the UV range accessible for observations. L a solar origin. However, this radiation can be excluded by filters. Despite all attempts to single out the metagalactic UV radiation has not yet succeeded. Only the top was experimentally established. the limits of its intensity (according to the minimum observed brightness of the sky and up to the contribution of cosmic rays to instrument counts).
By analogy with our Galaxy, it would be natural to assume that everything is normal. galaxies radiate little in UV rays, and that the intensity of this component of the F. to. small. However, an unexpectedly large flux of UV radiation was detected from the region of the nucleus of the M31 galaxy (Andromeda Nebula) and from a number of other galaxies. Important sources of F. to. and. in the UV range of the spectrum, according to observations from a specialist. satellites must be quasars.
Studying ultra-violet F. to. and. important for determining the number and properties of hot intergalactic. gas, which, perhaps, determines the density of matter in the universe. In particular, the red-shifted cosmological space falls into the band highlighted by the existing filters. shifted emission line L a of the most common element in the Universe, hydrogen, if it is located at a distance not exceeding 600 Mpc (at the Hubble constant Absence in the spectra of distant quasars of the absorption band corresponding to L a , speaks of a negligible density of neutral intergalactic. hydrogen, i.e., a high degree of ionization of intergalactic. gas 
, where n H and n P is the number of hydrogen atoms and protons in 1 cm 3 intergalactic. space.
Range not available for direct observa tions. This region of the spectrum is fundamentally inaccessible for direct observations from outside the solar system due to the absorption of photons of UV radiation by neutral interstellar hydrogen. There is only an indirect method for estimating the intensity of ionizing F. to. Background UV radiation should create zones of hydrogen ionization around galaxies, similar to HII zones that exist around hot stars. Obviously, if the background level were very high, then UV photons could ionize the entire interstellar gas. In fact, radio surveillance 21 cm hydrogen radio lines led to the discovery of a neutral gas far beyond the optical. boundaries of galaxies. The density of hydrogen there is extremely low, and the fact that it is not ionized speaks of the low intensity of the ultraviolet FK, its top. the limit is 100 times lower than in the neighboring observed range. Hydrogen at the periphery of galaxies turned out to be 100 times more sensitive detector than counters on satellites and rockets. The resulting limit is not so low: it corresponds to 10,000 ionizing photons falling on 1 cm 2 of the surface of galaxies in 1 s.
X-ray range Observations from rockets, satellites and cylinders showed that the radiation in the class-sich. x-ray areas 
highly isotropic, i.e., has an extragalactic nature. Only in the region of soft x-rays. rays (for photons with energy e<250 эВ) обнаруживается сильная
зависимость интенсивности диффузного излучения от галактич. координат. Спектр
рентг. Ф. к. и. оказался степенным. Исследования практически всего неба при
помощи приборов на спутниках позволили оценить амплитуду (<3%) мелкомасштабных
угл. флуктуации рентг. Ф. к. и. Эти наблюдения важны для космологии: в принципе,
наблюдения дипольной анизотропии рентг. фона позволят уточнить скорость движения
Солнечной системы относительно системы координат, в к-рой изотропно фоновое
излучение, создаваемое далёкими источниками. Наблюдения изотропии рентг. фона
могут дать ценную информацию об однородности и изотропии Вселенной.
The main sources of X-rays. F. to. and. are still unknown. Apparently, these are the nuclei of galaxies, hot intergalactic. gas in clusters of galaxies and quasars (ordinary galaxies provide no more than 1% of the observed X-ray background). With deep surveys of a number of sky areas with the Einstein X-ray. observatory (from the satellite HEAO-B, USA, 1978), up to ten roentgens were found at each square degree. sources. Their detailed analysis in Opt. range showed that 20-30% of them are quasars, 20-30% are distant galaxies, 20-30% are stars of our Galaxy. However, the radiation of these objects can provide no more than 50% of the intensity of the F. to. and. in roentgen. range. Some of the weak X-rays. sources cannot be identified with either optical or radio objects. X-ray launches are planned. satellites, to-rye will have to take a map of the entire sky in the range from 0.5 to 1.5 keV and put on it several. hundreds of thousands of roentgens. sources.
Origin of X-rays. F. to. and. may be due to the scattering of low-frequency photons by relativistic cosmic electrons. rays (reverse Compton effect). With such scattering, the energy of photons increases many times and they fall into the x-ray. range. In the nuclei of galaxies, apparently, multiple Compton scattering by thermal electrons is effective, leading to the formation of a hard X-ray. radiation in a hot nonrelativistic Maxwellian plasma. Another important mechanism of X-ray radiation. photons is the bremsstrahlung of the hot gas.
Gamma range Like the x-ray. radiation, g-radiation can arise under the inverse Compton effect and as bremsstrahlung of relativistic electrons during their interaction with a gas. In addition, g-photons can also be produced in other processes. These include, first of all, collisions of protons in space. rays with atomic nuclei of the interstellar medium, leading to the birth of p 0 -mesons; annihilation of protons and antiprotons, accompanied by the production and subsequent decay of p 0 -mesons into two g-photons; in addition, excitation by nonthermal particles and subsequent radiation of nuclei, annihilation of electrons and positrons. Since the cross sections and probabilities of all these processes are fairly well known, theorists calculated in advance the expected fluxes from discrete sources of gamma radiation, the flux of y-radiation from the plane of our Galaxy, and estimated the intensity of the gamma radiation background.
The Universe is transparent to hard g-radiation up to redshift values z~100. Therefore, according to the observed intensity F. to. one can draw an important conclusion about the amount of antimatter in the Universe: it is unlikely that there would be as much antimatter in the Universe as there is matter (see Fig. Baryon asymmetry of the Universe). Indeed, during the time corresponding to the change z from 0 to 100 (during this time, the cosmic microwave background radiation cools by about 100 times - from 300 K to 2.7 K), annihilated no more than one millionth of the matter of the Universe. Otherwise, the intensity of the background g-radiation would be much higher than the observed one. It can be expected that the high penetrating power of g-radiation will make g-astronomy a powerful tool for studying the evolution of the Universe.
Lit.: Longhair M.S., Sunyaev R.A., Electromagnetic radiation in the Universe, "UFN", 1971, v. 105, p. 41. R. A. Sunyaev.
This article was written by Vladimir Gorunovich for this site and the Wikiknowledge site.
CMB radiation(source) or more correctly background cosmic microwave radiation (English cosmic microwave background radiation) - cosmic electromagnetic radiation coming not from the stars of the Universe, with a spectrum characteristic of an absolutely black body with a temperature of 2.725 K and with a high degree of isotropy. The radiation maximum falls at a frequency of 160.4 GHz, which corresponds to a wavelength of 1.9 mm.
The existence of background cosmic (relic) radiation was predicted theoretically within the framework of the Big Bang hypothesis. Within the framework of this hypothesis, it is assumed that the relict radiation has been preserved from the initial stages of the existence of the Universe and fills it evenly. Along with the cosmological redshift, background cosmic (relic) radiation is considered by some physicists as one of the confirmations of the Big Bang hypothesis.
Currently, physics claims that the background cosmic (relic) radiation has sources other than the Big Bang. Therefore, the historical name of this radiation incorrectly reflects its nature and is misleading. This is also evidenced by the fact that the very existence of the "Big Bang" in the history of the universe is now rejected by physics as not corresponding to nature and its laws.
The existence of background cosmic (relic) radiation was experimentally confirmed in 1965.
- 1 Cosmic background radiation and the Big Bang hypothesis
- 2 Cosmic background radiation and field theory
- 3 Background cosmic radiation and classical electrodynamics
- 4 Background cosmic radiation and the law of conservation of energy
- 5 Natural sources of cosmic background radiation
- 6 Natural mechanism of formation of the main component of background cosmic radiation
- 7 CMB: Summary
1. Background cosmic radiation and the Big Bang hypothesis
According to the Big Bang hypothesis, the early Universe was a hot plasma consisting of protons, neutrons, electrons and photons (ie, baryons, one of the leptons and photons). It is argued that due to the Compton effect, photons constantly interacted with other plasma particles (protons, neutrons and electrons), experiencing elastic collisions with them and exchanging energy. Thus, the radiation had to be in a state of thermal equilibrium with matter, and its spectrum should correspond to the spectrum of an absolutely black body.
As the expansion of the Universe is assumed by the Big Bang hypothesis, the cosmological redshift (as expected) should have caused the plasma to cool, and at a certain stage it should have become energetically preferable for electrons to combine with protons (hydrogen nuclei) and alpha particles (helium nuclei), and form atoms. This process is called recombination. This could happen at a plasma temperature of about 3000 K and an estimated approximate age of the universe of 400,000 years. From that moment on, photons, as expected, ceased to be scattered by now neutral atoms and were able to move freely in space, practically without interacting with matter. The observed sphere corresponding to a given moment is called the last scattering surface in the Big Bang hypothesis. It is assumed that this is the most distant object that can be observed in the electromagnetic spectrum. As a result of the further expected expansion of the Universe, the radiation temperature has decreased and is now 2.725 K. (Data taken from Wikipedia and slightly modified).
And now a little criticism from the point of view of physics.
Neutrons (hidden behind the wording "baryons") are unstable elementary particles and after a time (about 1000 seconds), each neutron will decay into a proton, an electron and an electron antineutrino. Thus, this "cocktail" should consist of protons, electrons, photons and electron antineutrinos. In the process of neutron decay, the electron antineutrino, as an elementary particle with the smallest rest mass, will take a significant part of the decay energy. Then, as a result of collisions in intergalactic space with another antineutrino, both particles will pass into excited states with subsequent emission of low-energy photons - background cosmic radiation. So ignorance of the Big Bang hypothesis of the laws of nature does not exempt this hypothesis from their action.
And from protons and electrons it turns out - only hydrogen. As a result, a hydrogen Universe should be obtained, in the "relic" radiation of which spectral lines of hydrogen should be present. Helium atoms have nothing to create from, if you do not resort to stars and their thermonuclear reactions. But then the 400,000 years allotted by the hypothesis for the formation of helium by stars will be clearly not enough.
No one has proved the expansion of the Universe - this is just an assumption based on a one-sided interpretation of the redshift in favor of the Doppler effect and ignoring the interactions of elementary particles. It is also a fairy tale statement that after 400,000 years, photons were able to move freely in space, practically without interacting with matter. Here they forgot about antineutrinos, resulting from the decay of neutrons, and about photon-neutrino interactions, ignored by the standard model. They also forgot about the interactions of the antineutrinos themselves. And, finally, physics has not found evidence that there was a Big Bang in the history of the Universe.
Now why did it happen, or more precisely, why instead of the Big Bang theory, an erroneous hypothesis turned out.
In physics, one must be extremely careful in choosing the foundation of the theory being developed. Having laid the erroneous standard model in the foundation of the theory being developed, the authors took the wrong path and created an erroneous hypothesis. And this is not their fault that they believed the sweet-voiced speeches of the supporters of the standard model - but their misfortune. One should have first wondered if the Standard Model has too many arbitrary parameters that are excellently used to fit new experimental data. And if you still pay attention to the manipulation of the laws of nature, then everything will become clear. But there was no New Physics at that time and we had to take what was - the standard model.
So the mistake in choosing the foundation naturally led to an erroneous result. For physics, all this is obvious, but perhaps for cosmology it is new. And if so, then cosmology will have to undergo a course in respecting the laws of nature with a strict teacher called "Nature", as it was once with physics. True, it should be noted that a small part of physics (physics of elementary particles), with persistence worthy of a better application, tries to control the law of conservation of energy contrary to nature. And what came out of this prank is now clearly visible: fabulous "theories".
Thus, background cosmic radiation, mistakenly called "relic", was not created by the Big Bang and it must have other sources in nature .
2. Background cosmic radiation and field theory
The field theory of elementary particles as one of the sources of background cosmic radiation suggests the interaction of neutrinos (antineutrinos), emitted in gigantic quantities by stars. Since neutrinos, due to their extreme lightness (no more than 0.052 eV), carry away a significant part of the energy of thermonuclear fusion, they move at relativistic speeds and easily leave not only the star system, but also the galaxy. Colliding in intergalactic space with neutrinos from other stars, elementary particles pass into excited states. Then, after a certain time, the excited neutrinos pass into states with lower energy with the emission of low-energy photons. In this case, the emission of photons occurs in intergalactic space. Thus, the illusion of the appearance of electromagnetic radiation from nothing (apparent violation of the law of conservation of energy) or from the distant past (Big Bang) is created.
The next source of background cosmic radiation is the interaction of a photon with a neutrino. Photons of the light, ultraviolet or infrared range, colliding with a neutrino, give it a small, but non-zero, part of their energy. As a result, on the one hand, the neutrino passes into an excited state, followed by the emission of a quantum of microwave radiation, and on the other hand, the energy of the colliding photon decreases - i.e. redshift is created. Therefore, the redshift formation mechanism is one of the sources of background cosmic radiation.
Another source of background cosmic radiation is the annihilation reactions of pairs of elementary particles - this is the annihilation of a pair of "neutrino-antineutrino", here you can also add a pair of "electron-positron".
Thus, background cosmic (relic) radiation should include electromagnetic radiation of excited neutrinos (antineutrinos) , during their transitions to states with lower energy. Today, physics is unable to measure either the rest mass of the electron and muon neutrinos, or the energy of their excited states. Therefore, physics today cannot unambiguously say whether the background cosmic (relic) radiation is mainly the result of neutrino collisions, or whether it has other significant components.
3. Background cosmic radiation and classical electrodynamics
Classical electrodynamics states that any electromagnetic radiation, including background cosmic radiation, can only be created if the laws of electromagnetism, as well as other laws of nature, are complied with. This radiation can be created only by electromagnetic fields of elementary particles or their compounds (atoms, molecules, ions, etc.). In this case, the created radiation will interact with the electromagnetic fields of other elementary particles always and regardless of the "stage of creation of the Universe". - If there is a Universe, then, therefore, there are laws of the Universe, including the laws of electromagnetism, as an integral part of the Universe.
The cooling of a plasma in thermal equilibrium is possible only if the kinetic energy is spent, for example, on the formation of new "particle-antiparticle" pairs. But then, along with matter, antimatter will also be created with all the ensuing consequences and future universal cataclysms. And the expansion of the Universe must not be postulated, but proved.
The Big Bang article showed the contradictions between classical electrodynamics and the Big Bang hypothesis. Hence, background cosmic (relic) radiation must have natural sources other than the Big Bang .
4. Background cosmic radiation and the law of conservation of energy
According to the law of conservation of energy (which continues to operate in nature), electromagnetic radiation (which includes cosmic background radiation) cannot be created from forms of energy that do not exist in nature as a result of a hypothetical Big Bang, as well as as a result of hypothetical quantum fluctuations in a vacuum. Background cosmic radiation must have natural sources , for example: interactions, reactions and transformations of elementary particles (radiated by stars).
5. Natural sources of background cosmic radiation
Since the possibility of the Big Bang is rejected by physics, the background cosmic radiation cannot be relic radiation. Therefore, background cosmic radiation must have natural sources.
Among the possible natural sources of background cosmic radiation, physics suggests the following sources:
- radiation of excited neutrinos (both electronic and muon),
- annihilation reaction of a pair of electron neutrinos-antineutrinos,
- decay reactions of muon neutrino into electron with emission of photons (neutrino oscillations),
- radiation of individual atoms or molecules,
- radiation of neutrino gas molecules (bound states of several electron neutrinos).
In this case, the neutrino will go into excited states both from a collision with another neutrino, and from the passage of photons of the visible, ultraviolet, infrared and other ranges through the neutrino, for which the photon energy exceeds the value of the neutrino excitation energy. Thus, the source of neutrino excitation is also the light coming from distant galaxies, i.e. red shift.
6. The natural mechanism of formation of the main component of the background cosmic microwave radiation (article in development)
Today, physics has established the natural mechanism for the formation of the main component of the background cosmic microwave radiation and, therefore, one of its main natural sources.
In order to understand this, let's look at the map of cosmic background radiation (genuine, without adjustment for "cosmic background radiation"), placed at the beginning of the article (at the top). As you can see, it is cut in half by a red horizontal strip, reflecting the fact that the largest recorded radiation comes from our galaxy. Consequently, in our galaxy there are natural processes that create background cosmic radiation. Similar processes take place in other galaxies, as well as (more weakly) in intergalactic space.
And now let's ask ourselves a question: as a result of which this radiation can arise in interstellar, or intergalactic space. To do this, let's pay attention to the "elusive" elementary particle and its molecular compounds, poorly studied by physics.
According to the field theory of elementary particles, an electron neutrino should interact with other electron neutrinos by its electromagnetic fields. An example of the potential energy of interaction of a pair of electron neutrinos lying in the same plane with antiparallel spins is shown in the figure.
The figure shows the presence of a potential well with a depth of 1.54×10 -3 ev with a minimum at a distance of 8.5×10 -5 cm. As you can see, a pair of electron neutrinos should have a bound state with zero spin with an energy of the order 3 ev (a more precise value can be determined using quantum mechanics).
This bound state will resemble a hydrogen molecule, with the difference that in this “molecule” (ν e2) neutrinos interact with their electromagnetic fields. As a result of the extremely low value of the binding energy, the ν e2 molecule will be stable under conditions close to absolute cold and in the absence of collisions with other electron neutrinos and not only.
Electronic neutrinos can also form more complex bound states, with a higher binding energy, for example, ν e4 (etc.). As a result, the Universe should have a neutrino form of matter in the form of a neutrino gas, consisting mainly of molecules ν e2 , much less often ν e4 .
And this neutrino gas will interact both with light (creating a redshift) and with electron neutrinos emitted in huge quantities by stars. As a result of this interaction, the molecular compounds of electron neutrinos are broken into pieces. And during the reverse process - the fusion of a pair of electron neutrinos into a molecular compound, energy is released in the form of microwave electromagnetic radiation with a wavelength corresponding to the main component of the background cosmic microwave radiation (996). In addition, when a pair of molecules ν e2 merge into a molecule ν e4 even more energy is released, which corresponds to part of the spectrum 34 in the figure.
Thus, the background cosmic microwave radiation (erroneously called "cosmic microwave background radiation") has lost its divine origin and acquired natural sources..
7. CMB: Summary
The background cosmic microwave radiation, historically (erroneously) called relic must have natural sources . One such source is neutrino interactions.
In general, it is necessary to study in detail the entire spectrum of background cosmic radiation (in the entire frequency range, not limited to microwave frequencies) and determine its components, as well as their possible sources, rather than writing new biblical tales now about the creation of the Universe. For all sorts of "scientific" fairy tales, there is a great place in children's literature, unless, of course, the latter wants to kick them in the ass, as it did recently, and physics will continue to do.
Vladimir Gorunovich
