Active galaxies. Our Galaxy presentation for a lesson in astronomy (Grade 11) on the topic Download presentation on the topic of light of galaxies

Our Galaxy Physics. Astronomy. Grade 11 Teacher: Makarova Natalya Vladimirovna

One of the most remarkable objects in the starry sky is the Milky Way. The ancient Greeks called it the "milky circle". Already the first telescope observations made by Galileo showed that the Milky Way is a cluster of very distant and faint stars.

The Milky Way looks particularly impressive in the southern hemisphere. The southern part of the Milky Way

At the beginning of the 20th century, it became obvious that almost all of the visible matter in the Universe is concentrated in giant stellar-gas islands with a characteristic size from several parsecs to several tens of kiloparsecs. The Sun, together with the stars surrounding it, are also part of a spiral galaxy, always denoted with a capital letter: Galaxy. When we talk about the Sun as an object of the solar system, we also write it with a capital letter. The galaxy consists of a disk, a halo and a crown. The central, most compact region of the Galaxy is called the nucleus. The central, densest part of the halo within a few thousand light-years of the center of the Galaxy is called the bulge.

The galaxy emits in all ranges of electromagnetic radiation the Milky Way in various wavelength ranges

The distribution of stars in the Galaxy has two pronounced features: a very high concentration of stars in the galactic plane and a large concentration in the center of the Galaxy This is what our Galaxy looks like from the side

This is what our Galaxy looks like from above

In the Galaxy, every third star is a double, there are systems of three or more stars. More complex objects are also known - star clusters. Open star clusters meet near the galactic plane Open cluster M50 in the constellation Monoceros

Open clusters are made up of hundreds or thousands of stars. Their mass is small (100-1000 solar masses) Pleiades open cluster

Globular clusters stand out strongly against the stellar background due to the significant number of stars and a clear spherical shape. The diameter of globular clusters ranges from 20 to 100 pc. Globular cluster in the constellation Centaurus

Underwater corals? Enchanted castles? Space snakes? In fact, these mysterious dark columns are very dense gas and dust clouds of the M16 Eagle Nebula in the constellation Serpens.

The Great Nebula of Orion. This is a diffuse nebula

Central part of the Orion Nebula

Nebula Smoking Pipe

Planetary Nebula Cat's Eye

Eskimo planetary nebula

Cycle of gas and dust in the galaxy

Dark Horsehead Nebula

Layout of the Horsehead Nebula

Planetary nebula in the constellation Lyra

The center of the galaxy in infrared

The rotation of the Galaxy occurs clockwise, if you look at the Galaxy from its north pole, located in the constellation Coma Berenices. The angular velocity of rotation depends on the distance from the center and decreases with distance from the center. The Sun moves at a speed of 200 km / s around the center of the Galaxy and makes a complete revolution around the center in 220 million years

map of the milky way

"Galaxies and Stars" - Stages of star formation. Transformations. Giant clusters of stars. Gas cloud. Star. Andromeda's nebula. Galaxies and stars. Astronomical observations. Red giant. Age of the Metagalaxy. normal stars. A group of stars. Electrons. The current structure of the universe. Black hole. globular clusters.

"Types of galaxies" - Clusters of galaxies. Elliptical galaxies. spiral galaxies. Quasars and quasars. Active galaxies. Hubble tuning fork classification. Cloud. Distance to the galaxy. protogalactic clouds. Historical essay. Hubble law. Barred spiral galaxies. Local group of galaxies. The problem of the hidden mass of galaxies.

"Galaxies and Nebulae" - Butterfly Nebula. View from the Earth. Big. Launch of the Hubble Telescope. Nebula Ring. Nebula Cat's eye. Nebula Horsehead. A galaxy is a system of stars, interstellar gas, dust, and dark matter. . The Sombrero Galaxy. Andromeda Nebula as seen from Earth. Astronomy. By the early 1990s, there were no more than 30 galaxies.

"Types of galaxies" - Dwarf BCG galaxy. Leo 1 is a dwarf elliptical galaxy in the Local Group. Interacting Whirlpool galaxies. Interacting galaxy "Wheel". Elliptical galaxy M87. star clusters. Types of galaxies. This is what our Galaxy looks like from the side. Toward the center of the galaxy.

"The Origin of Galaxies and Stars" - The Lepton Era. The expansion of the universe. Explosion of galaxies. astronomical structures. Electroweak era. early universe. Hubble's law as a consequence of the homogeneity and isotropy of the universe. Hadron era. The age of the universe. Density of the Universe. Photon, atomic era. The visible universe. Expanding universe.

"Properties of galaxies" - General properties of galaxies. Types of spiral galaxies. spiral galaxies. Seyfert galaxies. Distances to nearby galaxies. Gravity-bound system. Radio galaxies. Diagram of a spiral galaxy. Large Magellanic Cloud. Andromeda. Elliptical galaxies. Galaxies. Andromeda's nebula.

There are 12 presentations in total in the topic

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Galaxies are giant stellar islands located outside of our star system (our Galaxy). They differ in their size, appearance and composition, conditions of formation and evolutionary changes.

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Democritus, an ancient Greek philosopher, believed that the Milky Way is a collection of faintly luminous stars. V. Herschel discovered many double, triple multiple stars. He presented a diagram of the structure of the Galaxy and its structure.

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I. Kant believed that our Galaxy does not include the entire stellar world and there are other stellar systems similar to it. E. Hubble discovered Cepheids in the Andromeda and Triangulum nebulae. His discoveries gave rise to a science called extragalactic astronomy.

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The distance from the center of the Galaxy to the Sun is 32,000 sv. years The diameter of the Galaxy is 100,000 sv. years The thickness of the galactic disk is 10,000 sv. years Mass - 165 billion solar masses Age of the Galaxy - 12 billion years

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The largest and smallest diameters of the bulge are respectively close to 20,000 and 30,000 sv. years The mass of the disk is 150 million times the mass of the Sun. The speed of rotation of the disk from the center is 200 - 240 m / s (at a distance of 2,000 light years. The rotation of the Sun around the center of the Galaxy is 200 - 220 km / s (one revolution in 200 million years). Satellites of the Galaxy: Large and Small Magellanic Clouds Large Magellanic Cloud Small Magellanic Cloud

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The location of the Sun in our Galaxy is rather unfortunate for studying this system as a whole: we are located near the plane of the stellar disk and it is difficult to determine the structure of the Galaxy from the Earth. In the area where the Sun is located, there is quite a lot of interstellar matter that absorbs light and the stellar disk is opaque.

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There are three main parts in the Galaxy - the disk, the halo and the crown. The central thickening of the disk is called the bulge.

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The halo consists mainly of very old, dim, low-mass stars. They occur both singly and in the form of globular clusters, which can include more than a million stars. The age of the population of the spherical component of the Galaxy exceeds 12 billion years. It is usually taken as the age of the Galaxy itself.

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Disk. The disk population is very different from the halo population. Near the plane of the disk, young stars and star clusters are concentrated, the age of which does not exceed several billion years. They form the so-called flat component. There are many bright and hot stars among them.

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The core of the central regions of the Galaxy is characterized by a strong concentration of stars: each cubic parsec near the center contains many thousands of them. The distance between stars is tens and hundreds of times less than in the vicinity of the Sun.

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I - Spherical II - Intermediate spherical III - Intermediate disc IV - Flat old V - Flat young

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Their diameter is 20-100 pc. Age 10 - 15 billion years Formed in the era of the formation of the Galaxy itself.

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Found near the galactic plane. Consist of hundreds or thousands of stars. There are also young (blue) stars in them.

What are galaxies? Galaxies are large star systems in which stars are connected to each other by gravitational forces. Based on the theory of the expanding Universe, scientists have established that galaxies began to emerge from gas and dust nebulae 10 billion years ago. There are galaxies containing trillions of stars. The smallest galaxies contain a million times fewer stars and are more like globular clusters in the Milky Way, only much larger. In addition to ordinary stars, galaxies include interstellar gas, dust, and various "exotic" objects: white dwarfs, neutron stars, black holes. In the centers of many bright galaxies there is a cluster called the nucleus, and inside the nuclei of some galaxies there are nucleoli - cores. The nature of nuclei differs sharply from the nature of other parts of galaxies. Active processes associated with the release of energy are observed in them. Known galaxies with unusually active processes in the nuclei. Gas in galaxies is not only scattered between stars, but also forms huge clouds (up to millions of solar masses), bright nebulae around hot stars, and dense and cold gas and dust nebulae. Large star systems have masses of hundreds of billions of solar masses. The smallest of the dwarf galaxies "weigh" only 100 thousand times more than the Sun. Thus, the mass interval of galaxies is much wider than that of stars: the "heaviest" and the "lightest" stars differ in mass by less than 1000 times. The appearance and structure of star systems are very different, and in accordance with this, galaxies are divided into morphological types.

Milky Way There are about 100 billion stars in our Galaxy, most of which are concentrated in a thin disk with a diameter of about 100 thousand light years and a thickness of about 3 thousand light years. They revolve around the center of the Galaxy in almost circular orbits. In particular, the Sun is rushing at a speed of about 200 km/s. Another 10 billion stars form a galactic "halo" - a giant sphere that surrounds the disk. Interstellar space is filled with gas and dust, and the main part of this interstellar medium also moves in circular orbits around the center of the Galaxy and, to an even greater extent than stars, is concentrated in its disk. As in the atmospheres of planets, the interstellar medium is densest "at the bottom" - in the plane of the galactic disk - and as you move away from it, the density decreases. However, up to 10% of the interstellar medium is located outside the disk and is carried at speeds exceeding the orbital motion by up to 400 km/s. These are high speed clouds. Their history began in the mid-1950s, when Guido Münch from the California Institute of Technology discovered dense clumps of gas above the plane of the Galaxy, where by all the rules they should not be: with distance from the plane, the gas pressure drops (as in the atmosphere of a planet) , so the clumps should quickly dissipate. In 1956, Lyman Spitzer (Jr.) of Princeton University proposed that the clumps are kept from expanding by the pressure of the hot gaseous corona surrounding the Milky Way, a galactic-scale version of the solar corona.

Classifications of galaxies According to the classification proposed by Hubble, in 1925 there are several types of galaxies: 1. elliptical (E), 2. lenticular (S 0), 3. ordinary spiral (S), 4. crossed spiral (SB), 5. irregular (ir).

Elliptical galaxies are a class of galaxies with a clearly defined spherical structure and decreasing brightness towards the edges. They rotate relatively slowly, a noticeable rotation is observed only in galaxies with significant compression. In such galaxies there is no dusty matter, which in those galaxies in which it is present, is visible as dark stripes against a continuous background of the stars of the galaxy. Therefore, outwardly elliptical galaxies differ from each other mainly in one feature - greater or lesser compression. The share of elliptical galaxies in the total number of galaxies in the observed part of the universe is about 25%.

Spiral galaxies are so named because they have bright, stellar-derived arms within the disk that extend almost logarithmically from the bulge (an almost spherical bulge at the center of the galaxy). Spiral galaxies have a central cluster and several spiral arms, or arms, which are bluish in color because they contain many young giant stars. These stars excite the glow of diffuse gaseous nebulae scattered along with dust clouds along the spiral arms. The disk of a spiral galaxy is usually surrounded by a large spheroidal halo (luminous ring around an object; an optical phenomenon) consisting of old second-generation stars. All spiral galaxies rotate at significant speeds, so stars, dust and gases are concentrated in a narrow disk. The abundance of gas and dust clouds and the presence of bright blue giants speak of active star formation processes occurring in the spiral arms of these galaxies. Many spiral galaxies have a bar (bar) in the center, from the ends of which spiral arms extend. Our Galaxy also belongs to barred spiral galaxies.

Lenticular galaxies are an intermediate type between spiral and elliptical. They have a bulge, halo, and disk, but no spiral arms. There are about 20% of them among all star systems. In these galaxies, the bright main body, the lens, is surrounded by a faint halo. Sometimes the lens has a ring around it.

Irregular galaxies are galaxies that show neither a spiral nor an elliptical structure. Most often, such galaxies have a chaotic shape without a pronounced core and spiral branches. In percentage terms, they make up one quarter of all galaxies. Most irregular galaxies in the past were spiral or elliptical, but were deformed by gravitational forces.

OUR GALAXY-Milky Way In 1609, when the great Italian Galileo Galilei was the first to point a telescope into the sky, he immediately made a great discovery: he figured out what the Milky Way is. With his primitive telescope, he was able to separate the brightest clouds of the Milky Way into individual stars! But behind them he distinguished dimmer clouds, but he could not solve their riddle, although he correctly concluded that they should also consist of stars. Today we know that he was right.

The Milky Way is made up of 200 billion stars. And the Sun with its planets is only one of them. At the same time, our solar system is removed from the center of the Milky Way by about two-thirds of its radius. We live on the outskirts of our galaxy. The Milky Way is in the shape of a circle. In the center of it, the stars are denser and form a huge dense cluster. The outer borders of the circle are visibly smoothed and become thinner at the edges. When viewed from the side, the Milky Way probably resembles the planet Saturn with its rings.

Structure of Our Galaxy Dimensions of the Galaxy: Dimensions of the Galaxy: - the diameter of the disk of the Galaxy is about 30 kpc (light years), - the diameter of the disk of the Galaxy is about 30 kpc (light years), - the thickness is about 1000 light years. - thickness - about 1000 light years. Our galaxy side view.

Scheme Structure of the Galaxy The galaxy rotates around the center. The sun makes one revolution around the center of the galaxy in 200 million years. The galaxy revolves around the center. The sun makes one revolution around the center of the galaxy in 200 million years. Model Rotation of the Galaxy.

View of Our Galaxy from other planets The galaxy contains two main subsystems nested one inside the other. The galaxy contains two main subsystems nested one inside the other. 1. Halo - its stars are concentrated towards the center of the galaxy. The central, densest part of the halo is the bulge. 1. Halo - its stars are concentrated towards the center of the galaxy. The central, densest part of the halo is the bulge. 2. Star disk - two plates folded with edges. The Sun is located in the stellar disk between the spiral arms. 2. Star disk - two plates folded with edges. The Sun is located in the stellar disk between the spiral arms.

Open Star Cluster Every third star in the Galaxy is a binary one, there are systems of three or more stars. More complex objects are also known - star clusters. In the Galaxy, every third star is a double, there are systems of three or more stars. More complex objects are also known - star clusters.

Globular Star Clusters Globular clusters stand out strongly against the stellar background due to the significant number of stars and a clear spherical shape. Globular clusters stand out strongly against the stellar background due to a significant number of stars and a clear spherical shape. Globular cluster in the constellation Centaurus.

Interstellar Matter The space between stars is filled with rarefied matter, radiation and magnetic field. The space between stars is filled with rarefied matter, radiation and magnetic field. If the concentration of these substances becomes large, then we can see various types of nebulae. If the concentration of these substances becomes large, then we can see various types of nebulae. Gas and dust clouds of the M16 Eagle nebula in the constellation Serpens. Dark Nebula Horsehead

Elliptical Galaxies The stars of elliptical galaxies revolve around the center of the galaxy very slowly (the rotation speed usually does not exceed several tens of km/s). impulse. They make up about 25% of the total number of high-luminosity galaxies. They are usually denoted by the letter E (English elliptical). The stars of elliptical galaxies revolve around the center of the galaxy very slowly (the rotation speed usually does not exceed several tens of km/s). impulse. They make up about 25% of the total number of high-luminosity galaxies. They are usually denoted by the letter E (English elliptical). Elliptical Galaxy M87

Spiral Galaxies In 1845, the English astronomer Lord Ross discovered a whole class of "spiral nebulae". The nature of these nebulae was established only at the beginning of the 20th century. The flat disc shape is due to rotation. In 1845, the English astronomer Lord Ross discovered a whole class of "spiral nebulae". The nature of these nebulae was established only at the beginning of the 20th century. The flat disc shape is due to rotation. Spiral galaxy NGC2997 Spiral galaxy M104 Sombrero

Irregular Galaxies In the study of the sky with the help of telescopes, many irregular, ragged galaxies have been discovered. About half of the matter in them is interstellar gas. When studying the sky with the help of telescopes, many irregular, ragged galaxies were discovered. About half of the matter in them is interstellar gas. Irregular galaxies NGC1313

Quasars In 1960, scientists turned their attention to star-shaped objects, sources of powerful radio emission. After analyzing the spectra of these sources, it was found that they are at a distance of more than a billion light years. Such objects were called quasars. In 1960, scientists drew attention to star-shaped objects, sources of powerful radio emission. After analyzing the spectra of these sources, it was found that they are at a distance of more than a billion light years. Such objects have been called quasars.