More on the Milky Way
Heart of the Milky Way: The center of the Milky Way is unlike any other part of the Galaxy. It is a bar-shaped bulge of old red and yellow stars with comparatively little gas. Until recently, what lay at the center of this bulge was a mystery, because huge clouds of gas and dust block the view of optical telescopes. Now radio and infrared telescopes have revealed some of the amazing features that lie there, including rings or jets of gas moving at a considerable speed, and areas of powerful magnetism. Toward the core, the temperature starts to climb. Together, these things indicate that the center is a very disturbed and energetic place. The activity is stirred partly by a recent bout of star formation and partly by energy released by gas falling into a massive black hole. Magnetic Structures: The innermost 100 light-years are dominated by magnetic fields a thousand times stronger than those found elsewhere in the Milky Way. These are obvious in the filaments making up the Arc. This is part of the Radio Lobe, a vast region of magnetized gas in the shape of a chimney. Within this magnetized region are many strange objects unique to this part of the galaxy, such as the Mouse, which is probably a neutron star speeding through space. The Radio Lobe has a tail which is 100 light-years long. The origin of the magnetic fields is unknown. Central Spiral: The central 10 light-years consist of three regions: Sagittarius A West, Sagittarius A*, and the central star cluster. Sagittarius A West looks like a tiny spiral galaxy, but the smaller spiral arms are streams of gas falling inward, while the two main arms are parts of a tilted spinning disk of hot gas. The rate at which the disk spins shows that the material inside it has a mass equal to 5 million suns. Within Sagittarius A west is the central star cluster, which contains 2.5 million stars. Right at the center is Sagittarius A*, a black hole with a mass of 2.5 million Suns. It is not active at the moment, but it was once. If enough gas exists to “feed” and fuel it, it may become active again in the future.
Structure of the galactic center: The center is the place where the Milky Way’s biggest and heaviest objects conjugate. At its core is a star cluster, many of whose members are red supergiants moving rapidly under the influence of strong gravity, and an intense radio source called Sagittarius A*. The high speed of the stars proves that Sagittarius A* is a massive black hole.
Central Galactic Features
Galaxies | Milky way | More on Milky Way | The Local Group | Types of Galaxies | Structure of galaxies | AGN and Quasars
|
