Structure of cluster of galaxies
||Updated June 01, 2013|
Galaxy clusters are the biggest structures of the Universe. They are constituted by hundreds of galaxies bound together by their own gravitational attraction. Between the galaxies we find some matter constituted by warm gas there, forming a plasma, the temperature of which reaches 10 to 100 million degrees. This plasma is a strong transmitter of X-rays. The spectrum analysis of these X-rays informs about the temperature of the heap and about its dynamics. Galaxy groups form in the crossings of the strands which compose this cosmic cobweb. The Universe being constituted by matter distributed along its immense strands between which are vast bubbles empty of matter. The matter passes by along strands and converges on the knots of the cloth to form groups, then galaxy groups. Galaxy groups are not constituted that of galaxies, they are filled with extremely warm gas (10-100 million degrees) and of weak density (1 000 particles/m3). This gas is distributed in a much more diffuse and more vast way than the galaxies.
These gases fill the space between the galaxies and constitute the essential of the groups, representing a mass more important than the galaxies themselves. In these temperatures, it is totally ionized, it is about a plasma.
Image: Image of the density of a thin slice of the universe. The structure spiderweb clusters of galaxies seems to bind all these clusters by filaments of matter.
The Milky Way and the Big Nebula of Andromeda have satellite galaxies. These two huge spirals belong to an even bigger grouping of 20 galaxies among which M31, M33, Maffei I and Maffei II, the Big and the Small Cloud of Magellan, conscript Groups it local. All these galaxies move around a common center situated between our Galaxy and the Nebula of Andromeda. All the observers know the biggest and the most brilliant of all: M31, in the constellation of Andromeda. The most known heap of galaxies are Virgo, Pegasus I, Pisces, Cancer, Perseus, Coma, Ursa Major III, Hercules, Pegasus, Heap A, Centaurus, Ursa Major I, Leo, Gemini, Corona Borealis, Heap B, Bootes, Ursa Major II, Hydra II Distant from 2,5 million light years, it is the closest galaxy but especially it is the only one who is visible in the bare eye, on dark night. We can consider the Local Group, or the other groups looking like it as heap containing a number relatively restricted by objects. Galaxy groups can be more important. If we come down until the magnitude 21, there would so be 75 million galaxies among which our.
The local group is a part of an enormous complex of 10000 galaxies assembled in heap extending over some 200 million years lights, conscript local super clusters or super clusters of the Virgo. The super clusters of the Virgo and super clusters of the Hydra and the centaur fall themselves towards another big conglomeration of galaxy groups which we call the Big Attractor. Galaxy comes from Greek " galactos " which wants to say milk. Of our ground base, we participate in a fantastic cosmic ballet: the Earth propels us in 30 km/s around the Sun which splits the space in 230 km/s around the Milky Way.
Image: few galaxies in our Local Group of galaxies. Author Richard Powell.
The heap of the Virgo (Virgo) is a massive group of galaxies which dominates the super clusters of the Virgo. It is the closest heap of galaxies of our Galaxy, the Milky Way.
Image: The group of galaxies Virgo, dominated by M86 (at the top), M84 (to the right), NGC 4388 below and NGC 4387 in the middle.
The heap of Coma is a galaxies group, spherical, very dense in its center.
Image: Galaxies group Coma
The super clusters of Coma (Bernice's Hair) is one of galaxies group the most known.
The group of galaxies Fornax is in about 65 million light years of the Earth. The galaxies of the heart of the heap Fornax seem to move in the direction of a common point, attracted by the dominant gravity of invisible structures of dark matter of this region.
Image: The group of galaxies Fornax of the look-out observatory Chandra reveals emissions with high energy of several huge galaxies close to the center of the heap Fornax and an immense diffuse cloud of warm gas emitting X-rays.
On the photo above, the blue objects are galaxies and the yellow objects are stars in the foreground.
Image: clusters Shapley A3558
The group of galaxies of the Hydra, nicknamed so because of the constellation which accommodates it, covers approximately 10 million light years and contains more than 100 brilliant galaxies.
Image: Galaxies group Hydra
Clusters of galaxies Hydra or Abell 1060
This group of galaxies is probably in the process of fusion. This amazing set of three galaxies is known group NGC 7771 lies about 200 million light-years away in the constellation Pegasus.
Among the billions of stars that merge into a single galaxy, probably few stars collide with each other due to the vast "empty" space. Red regions of galaxies are regions of star formation. The blue areas are hot young stars that have already formed. One can also observe regions of dust around galaxies that show the incredible amount of matter that exists around.
Image: The cluster of galaxies NGC 7771, includes NGC 7769 galaxy bottom left image, the large galaxy NGC 7771 on the right and the small galaxy NGC 7770 above NGC 7771. credit & copyright: Kent Biggs
Stephan's Quintet is a group of galaxies, that is a group of very close galaxies some of the others. It contains normally 5 main galaxies but only 4 are visible on this image. The galaxies incur because of their strong mass and it is likely that they will merge one day. The galaxies are strongly perturbed by the effect of their gravitational interaction.
Image: The group of galaxies of Stefan's Quintet or ESO 3598. Well known by the amateurs, the group of the Quintet is situated in the constellation of Pegasus, about a distance about 340 million light years of the Milky Way and was discovered in 1877 by the French astronomer Edouard Stephan, since the look-out observatory of Marseille.
Perseus galaxy cluster or Abell 426
The Perseus cluster (Abell 426) is part of the Perseus-Pisces Supercluster (Pisces-Perseus) in the constellation of Perseus, 250 million light years. It contains about 190 galaxies and the Perseus-Pisces Supercluster contains about 1000 galaxies. This is one of the biggest visible sky objects. Almost all visible spots on the image are galaxies. The Perseus cluster is one of the closest galaxy clusters. The first star map belongs to our own Galaxy, the Milky Way, they are distinguished by their diffraction spikes. At the center of the cluster, the main galaxy of the cluster NGC 1275 can be seen, this is the largest galaxy visible on the left of the image. The galaxy NGC 1275 is a prodigious source of X-radiation and radio.
Image: The Perseus cluster of galaxies, or Abell 426. The Perseus cluster is part of the Perseus-Pisces Supercluster in the constellation of Perseus, located about 250 million light years.
Seyfert Sextet cluster
Seyfert Sextet is a group of galaxies located about 200 million light-years, in the head of the constellation Serpens. The constellation Serpens is the only constellation divided into two parts, the head and the tail, separated by the constellation Ophiuchus. The cluster galaxies Seyfert Sextet actually contains only 4 galaxies in gravitational interaction.
The galaxy NGC 6027a bottom of the image is a spiral galaxy in vertical position. The beautiful spiral galaxy NGC 6027d, the only galaxy seen from above, a small galaxy is more distant than others and is not part of the cluster of Sextet Syfert, it is likely that this group of galaxies, except NGC 6027d, bound by gravity in a confined space, merged into one large galaxy in the next billion years. Each of interacting galaxies has a width of about 35 000 light-years.
Image: This image from the Hubble Space Telescope, shows us the Seyfert Sextet is a group of galaxies in the constellation Serpens about 200 million light years.
Cluster of galaxies Abell 2744
The Hubble Space Telescope still amazes us with this cluster of galaxies Abell 2744 is the most massive and deepest ever photographed all clusters of galaxies. This photograph shows some of the youngest galaxies ever detected in the deep cosmos. The immense gravity of the cluster Abell 2744 distorts space so that the image we see is distorted by the curvature, as through a lens we see the magnified galaxies that are much farther behind Abell 2744.
Long exposure Hubble images will be combined with Spitzer and Chandra X-ray Observatory NASA to provide new insights into the origin and evolution of galaxies and their black holes companions.
Image: This long exposure of the galaxy cluster Abell 2744 is performed by the Hubble Space Telescope. The image of the cluster massive galaxies (foreground) is the deepest ever made. The farthest galaxies around 12 billion years, they were born shortly after the Big Bang.