Why are some galaxies spiral shaped?

You Know what surprised me the most? The fact that we perceive the surrounding world as it is. Animals, plants, the laws of physics and the cosmos are perceived by many people as something so mundane and boring that they invent fairies, ghosts, monsters and sorcery. Agree, this is surprising, because the very fact of our existence is magic. Look at those giraffes, well as such things with a long neck did it happen? And the platypus, echidna, porcupines and all the other animals? I think you know what I mean. The same applies to space. Isn't it amazing the very existence of planets, stars and galaxies? And isn't it great that we can learn them? So, milky Way galaxy (which is our Sun and the Earth) – one of billions of galaxies in the vastness of the infinite Universe, but we know what shape and what form are most galaxies in the observable Universe. In this article, you will learn something amazing about the world in which we live – namely, why are some galaxies spiral-shaped?

What is a galaxy?

In space, everyone manages the force of gravity. If it is not, that the vast infinitely expanding – and even acceleration – of the Universe would be no galaxy. After the Big Bang, which occurred 13.8 billion years ago, continued to expand, it gradually cools down. After the end of the dark ages – beginning with the condensation of neutral gas, gradually began to form clumps of matter.

In fact, the galaxy is a large gravitationally bound systems of clusters of matter, stars, clouds of gas and dust, dark matter and planets. In this case, all objects in the galaxy move relative to a common center of mass of a supermassive black hole located in the center of galaxies. Strange, isn't it? Therefore, scientists are trying to learn as much as possible about this mysterious place.

What are the forms of the galaxy?

You May be surprised, but a detailed study of galaxies began only in 1920-ies of the last century. While the stars and planets have never been deprived of human attention, the beginning of extragalactic astronomy put an outstanding scientist Edwin Hubble. He proved that many nebulae, which conducted observations astronomers were other galaxies, consisting of countless stars. Hubble studied more than a thousand galaxies and determined the distances to some of them. Moreover, it was Edwin Hubble first identified three main types of galaxies: spiral, elliptical and irregular. It turned out that spiral galaxies in the Universe occur most frequently. Heck, more than half of galaxies – spiral, the Andromeda galaxy and galaxy Triangle. But why?

the Magnetic fields – the key to unlocking the secrets of spiral galaxies

Scientists are still puzzled by spiral galaxies and how they acquire their shape, with graceful sleeves full of stars. In fact, a spiral galaxy is the iconic form of the most galaxies in the Universe. In trying to understand why astronomers observing spiral galaxies, which differ from the milky Way. Recently, researchers using the stratospheric Observatory infrared astronomy, SOFIA watched the galaxy M77, also known as NGC 1068 and presented the results in a new study to be published soon .

As reported by the authors in the official press release, the magnetic fields play an important role in the formation of spiral galaxies such as M77. Magnetic fields are invisible, but can affect the evolution of galaxies. Today, scientists understand pretty well how gravity affects galactic structure, but the role of magnetic fields in these processes have yet to learn.

the Sleeves of the spiral galaxies seem to be full of stars

M77 is a spiral galaxy, which lies about 47 million light-years from Earth. The researchers came to the conclusion that M77 is an active galactic nucleus, is two times more massive than Sagittarius A* – black hole in the center of the milky Way. For its size M77 more than the milky Way: its radius is about 85,000 light years, and the radius of the milky Way – about 53 000. However, in the galaxy M77, there are about 300 billion stars in the milky Way, they are about from 250 billion to 400. M77 spiral arms filled with regions of intense star formation, called star flashes. The magnetic field lines closely follow the spiral arms, although to see them in a normal telescope can not. Fortunately, it can make SOFIA a result, astronomers have learned that the existence of magnetic fields supports the widespread theory that explains how the sleeves of spiral galaxies acquire their form. Itcalled «theory of density waves».

the Hubble Space telescope allowed us to look into the abyss of the cosmic ocean

So, galactic sleeves is the visible part of the density waves, and stars move in and out of them. Thus, the sleeves of spiral galaxies are not permanent structures, made of stars, although they look that way. Observations using SOFIA have shown that the magnetic field lines stretch along the entire sleeve galaxy M77 at a distance of 24,000 light years. According to the results of gravitational forces that helped create the spiral shape of the galaxy, how would compress the magnetic field, thus confirming the theory of density waves. Clean space madness, is not it?

However, the study only deals with one spiral galaxy, so that astronomers have a lot of work. While it remains unknown what role can play the magnetic field lines in the structure of other galaxies, including irregular, but despite the huge number of questions we have already learned much about the world in which they live and these .

is the galaxy