In the spare time of checking the flow of information, Hua Feng informed Bai Feng and Yun Meng of the ins and outs of the whole matter, Bai Feng returned to his room after relieving his heart, while Yun Meng slowly cultivated by Hua Feng's side.

Sagittarius A has an extremely small scale, the size of an ordinary star, emits radio radiation of 2 x 10 (to the 34th power) Erg/s, and is located within 0.2 light-years of the Milky Way's dynamic center.

It is surrounded by moving ionized gases with speeds of up to 300 km/s, as well as strong sources of infrared radiation. The activity of all known stellar objects does not explain the singular properties of Sagittarius A, so Sagittarius A appears to be the best candidate for massive black holes. But because there is currently no conclusive evidence for massive black holes, astronomers are careful not to refer to massive black holes in conclusive language.

Our galaxy contains about 200 billion stars, of which about 100 billion stars, and the Sun is a typical one. The Milky Way is a fairly large barred spiral galaxy that consists of three parts, including a galactic disk containing a spiral arm, a galactic center with a central protrusion, and a halo part.

The spiral galaxy M83, which is similar in size and shape to our Milky Way. Outside the galactic disk is a spheroid body of sparse stars and interstellar material, called a halo, about 160,000 light-years in diameter.

The Milky Way also has a rotation. The solar system revolves around the center of the Milky Way at a speed of 250 km/s for about 220 million years. The Milky Way has two companion galaxies: the Large Magellanic Galaxy and the Small Magellanic Galaxy.

Astronomer Maria German believes that the study of the disk of the galaxy's star clusters shows that the inner cluster of stars in the Milky Way is older, while the outer stars are younger, and it can be speculated that the formation process of the Milky Way began from the interior and gradually evolved to a diameter of more than 100,000 light-years.

Scientists say the investigation also uncovered new evidence that the Milky Way also swallowed up many small galaxies as it grew, and that objects from other galaxies merged into the Milky Way's interior. [5] Stephen Hawking once claimed that his observations indicated that the center of the Milky Way was a massive black hole.

In June 2013, NASA unveiled the sharpest Milky Way image with a capacity of 160 million pixels and a capacity of 457MB.

The main part of the Milky Way's matter makes up a thin disk called a silver disk. The almost spherical part of the central bulge of the silver disk is called the nuclear sphere, and the stars are highly dense in the nuclear sphere region.

There is a small dense zone in the center of the nuclear sphere called the silver nucleus. Outside the silver disc is a larger, nearly spherical region in which the density of matter is much lower than in the silver disk, called the galactic halo. There is also a silver crown on the outside of the silver halo, and its material distribution is also roughly spherical.

In 2005, the structure of the Milky Way's spiral arm was observed. The Milky Way is supposed to be a huge barred spiral galaxy SBc (Spiral Arm Loose Barred Spiral Galaxy) with a total mass of 0.6 trillion to 3 trillion times the mass of the Sun, with about 100 billion stars.

Beginning in the 80s, astronomers suspected that the Milky Way was a barred spiral galaxy rather than an ordinary spiral galaxy. In 2005, the Spitzer Space Telescope confirmed this suspicion and also confirmed that the rod-like structure in the galactic core was larger than expected.

The Milky Way's disk is estimated to be 98,000 light-years in diameter, and the distance from the Sun to the center of the Milky Way is about 26,000 light-years.

The center of the Milky Way has a massive mass and compact structure, so it is suspected that it has supermassive black holes, because there are already many galaxies that are believed to have supermassive black holes in the core.

Like many typical galaxies, the speed of an object orbiting the center of the Milky Way is not determined by its distance from the center and the distribution of the Milky Way's mass. Leaving the core bulge or on the periphery, the typical velocity of the star is between 210~240 km/s.

Therefore, the period of these stars orbiting the Milky Way is only related to the length of their orbits. This is different from the solar system, where different orbital velocities correspond to different distances.

The Milky Way's rod-like structure, about 27,000 light-years long, lies at an angle of 44±10 degrees between the Sun and the center of the Milky Way, and is composed mainly of red stars, mostly old stars.

It is inferred that each of the spiral arms of the observed galactic spiral arm structure is given a numerical correspondence (like the spiral arms of all spiral galaxies), which can be divided into about a hundred segments. There are four main spiral arms that originate from the core of the galaxy, including:

2 a

D 8 - 3,000 parsec arm and Perseus spiral arm.

3 a

D 7 - Rectangular Ruler Spiral Arm and Cygnus Spiral Arm (together with the recently discovered extension - 6).

4 a

D 10 - Southern Cross Spiral Arm and Shield Seat Spiral Arm.

5 a

D 9 - Boat base and Sagittarius arm.

There are also two small spiral arms or branches, including:

11 - Orion spiral arm (including the Sun and the solar system - 12).

New research has found that the Milky Way may have only two main spiral arms, the Sagittarius and Histogram, which are mostly gas, with only a handful of stars dotted around.

The Gude Belt (this cluster) is a belt of bright stars that stretches out from one end of the Orion arm, the main members are B2~B5 type stars, there are also some O-type stars, diffuse nebulae and several star associations, the closest OB star association is the Scorpio-Centaur star association, about 400 light years away from the sun.

On the outside of the main spiral arm is the outer ring, or known as the Monocerosis ring, which was created by astronomer Brian Yanney (B. Brown).

ia

Ya

y) and Heidi Jo Newbe

g) is a ring of stars that orbit the Milky Way, including stars and gases that interacted with other galaxies billions of years ago.

The disk of the Milky Way is surrounded by a spherical silver halo with a diameter of 250,000~400,000 light years. Since the gas and dust on the disk absorb some wavelengths of electromagnetic waves, the composition of the silver halo is not clear. The disk (especially the spiral arm) is the active region where stars are born, but there is no such activity in the galactic halo, and open clusters are mainly found on the disk.

It is generally believed that most of the stars in the Milky Way are binary or clustered stars. A new discovery in 2006 suggests that two-thirds of the Milky Way's main-sequence stars are single. Most of the matter in the Milky Way galaxy is dark matter, and the dark silver halo formed has 0.6 trillion ~ 3 trillion solar masses, centered on the silver core.

The new discoveries have increased our understanding of the structure and dimensions of the Milky Way than was previously obtained from the disk of the Andromeda Galaxy (M31). Newly discovered evidence confirms that the outer ring is extended by the spiral arm of the constellation Cygnus, clearly supporting the possibility that the Milky Way disk extends outward. The discovery of the Sagittarius dwarf ellipsoid galaxy and the fragments of galaxies in orbit around the galactic pole suggest that it was torn apart by its interaction with the Milky Way. Similarly, the Dwarf Canis Major Galaxy also interacts with the Milky Way, causing the debris to surround the Milky Way on the disk.

9 January 2006, Ma

io Ju

IC and some at Princeton University have announced that the Sloan Digital Survey has discovered a large cloud structure in the Northern Hemisphere sky (spanning an area about the size of about 5,000 Full Moons) within the Milky Way, but it does not appear to fit all current models of the Milky Way. He converging some stars in a vertical line perpendicular to the disk where the spiral arms are located, possibly as a result of the merger of small dwarf galaxies with the Milky Way. This structure is located in the direction of the constellation Virgo, at a distance of about 30,000 light-years, and is tentatively known as the Virgo stellar jet.

On May 9, 2006, Da

iel Zucke

and Vasily Beloku

The OV announced that the Sloan Digital Survey has discovered two more dwarf galaxies in the constellations Canis and Pastorus.

The Milky Way's name comes from the fact that it is a band of light that spans the night sky. The name "Milky Way" is translated from the Latin via lactea, which in turn comes from the Greek γαλαξίας κύκλος (galaxías kýklos, "milky ci."

cle"). In 1610, Galileo Galilei used a telescope to first explain that the ring was formed by the aggregation of stars.

In 1785, F.W. Herschel was the first to study the structure of the Milky Way. He used the stellar counting method to conclude that the stars of the Milky Way are distributed in the shape of a flat disk, and the sun is located in the center of the disk.

In 1918, H. Shapley studied the spatial distribution of globular clusters and established a lenticular model of the Milky Way, with the Sun not centered.

In the 20s of the 20th century, the Shapley model was recognized. However, since interstellar extinction is not accounted for, the values of Shapley's model are inaccurate. The study of the structure of the Milky Way has traditionally been done with optical methods, but with certain limitations. Radio methods and infrared technology, which have been developed in recent decades, have become powerful tools for studying the structure of the Milky Way. On the basis of Shapley's model, we have a deep understanding of the structure of the Milky Way.

The silver disk is the main component of the Milky Way, and ninety percent of the detectable matter in the galaxy is within the range of the silver disk. The shape of the silver disc is like a thin lens, distributed around the silver core in an axisymmetric form, and its center thickness is about 10,000 light years, but this is the thickness of the slightly raised nuclear sphere, and the thickness of the silver disk itself is only 2,000 light years, and the diameter is nearly 160,000 light years, which is very thin in general.

Except for the silver core within the range of 1,000 parsecs that rotates around the center of the silver as a rigid body fixed axis, the rest of the silver disc rotates around the center of the silver in a poor way, that is, the farther away from the center of the silver, the slower it turns.

The matter in the silver disk is mainly in the form of stars, and the vast majority of interstellar matter, which accounts for less than 10% of the total mass of the Milky Way, is also scattered in the silver disk.

In addition to ionized hydrogen, molecular hydrogen and a variety of interstellar molecules, there are 10% of interstellar dust, and these solid particles with a diameter of about 1 micron are the main cause of interstellar extinction, most of which are concentrated near the galactic surface.