bookGalaxyLocal Group of GalaxiesGalaxyAnd adjacentAndromeda galaxy、Magellanic Clouds 50 galaxies formed a smaller group, including the Milky Way.All galaxies in the Local Group of Galaxies cover an area about 10 million light-years in diameter.The local galaxy group belongs to the largerVirgo supercluster 。[1]
The Local Group of Galaxies is a typicalOpen galaxy clusterThere is no obvious trend of gathering towards the center.Member galaxyAbout 50.GalaxyandAndromeda galaxyThey are the largest two of the member galaxies of the local galaxy group, and they are generally located in the center of the local galaxy group.Except the Milky Way and Andromeda Galaxy, most of the member galaxies areDwarf galaxy。
The radius of the local galaxy group is about one millionSecond gapWith a mass of about 6.5 trillionSolar massMost of them are concentrated in the Milky Way and Andromeda Galaxy.There is not much gas in the group, accounting for aboutTotal mass2%.
The so-called local galaxy group refers to the general name of galaxies in space with a radius of about one million seconds (more than 3 million light years), including the Milky Way where the Earth is located. Some people also define the center of the local galaxy group as the Milky Way andAndromeda galaxy(M31).Known local galaxy groupMember galaxyAnd about 50 possible member galaxies.All galaxies in the Local Group of Galaxies cover an area about 10 million light-years in diameter (please refer to 1E23m for a detailed concept of this distance).The local galaxy group belongs to the largerVirgo supercluster 。
The mass of other members of the local galaxy group is far less than that of these large onessubgroup。The local galaxy group is a huge open group, and has no tendency to concentrate toward the center.However, members three and five of them are grouped into subgroups, at least withGalaxyandAndromeda galaxyIs the center of two subgroups.The total mass of the local galaxy group is 65600 trillion solar mass, and the sum of the masses of the Milky Way and Andromeda Galaxy accounts for the vast majority.
a little distanceGalaxy clusterThe spatial distribution ofvirgo cluster Higher level centeredGalaxy clusteringPhenomenon, with a size of about 100 million light-years and a length diameter of about 30-75 million seconds, including about 500 galaxy clusters andGalaxy cluster, calledLocal superclusterThe local galaxy group is a member of it.
It is speculated that the main members of the local galaxy groupAndromeda galaxyAnd our Milky Way will soon fall into the destiny of integration.However, since the two galaxies are 2.5 million light-years away, it may take a long time for the two galaxies to merge.But in the distant future, billions of years later, two giant galaxies will merge into one and grow into even larger galaxies.AndAndromeda galaxyAnd ourGalaxyLike merging, other galaxies may also be close to each other and merge into one.With the passage of billions of years, all the galaxies in the local galaxy group will merge with each other and eventually form a giant galaxy.The rotational motion of galaxies will gradually disappear with the merger, and eventually a hugeElliptical galaxy。
originalUMa dSph (Palomar 4) is a globular cluster of galaxies, previously classified as a globular dwarf galaxy in the constellation Ursa Major
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Local galaxy group
The general name of galaxies in space with a radius of about one million seconds (more than 3 million light years) centered on the Milky Way.Some people also define the center of the local galaxy group as the Milky Way andAndromeda galaxy(M31).There are about 500 known member galaxies and possible member galaxies of the local galaxy group.There are two giantSpiral galaxy(Galaxy and Andromeda), a medium-sized spiral galaxy（Triangular galaxy）, a dwarfBarred spiral galaxy（Large Magellanic Cloud）, may also include a lens typeGiant galaxy（Mafei 1）, the rest areDwarf elliptical galaxyandIrregular galaxy。
The local galaxy group is a typical open group, and has no tendency to concentrate toward the center.However, the members three and five of them converge into sub groups, and there are at least two sub groups centered on the Milky Way and Andromeda Galaxy.The total mass of the local galaxy group is 650000 trillion times the mass of the sun, and the sum of the masses of the Milky Way and Andromeda Galaxy accounts for most of it.The spatial distribution of close galaxy clusters shows thatvirgo cluster The cluster phenomenon of higher level galaxies at the center is about 100 million light-years in size and about 30-75 million seconds in length and diameter, including about 500 galaxy clusters and galaxy clusters, calledLocal superclusterThe local galaxy group is a member of it.
