Spiral Galaxy ESO 510-13

Figure Obtained from: Astronomy Picture of the Day

          The picture above was obtained but Astronomy Picture of the Day. It was posted on March 4^th 2012.  This shows a spiral galaxy edge on and it has a distinctive warped appearance. A galaxy is a collection of millions, billions, or even trillions of stars gas and dust that are gravitational bound. The material rotates around a center.  The center of the galaxy is the location of a supermassive black hole. Like our Milky Way Galaxy this galaxy is spiral. As well from the edge on view one can see the dimensions of the galaxy. The length of the galaxy is enormous compared to the thickness of the galaxy.  The dark bands that are shown in the figure above are where the gas and dust as well as some stars are located.  As well there is a large part of the galaxy that we are not able to see. This is the large amount of dark matter that is located at the edge of the visible galaxy and it expands out to large distances.  This dark matter is what allows deviations in Kepler’s third law. If the orbit of the stars around the galactic center follows Kepler’s third law then the further the star is away from the center the slower it orbits of the stars around the center are. However, this is not true for galaxies. The speed of rotation increases up until a certain point and then it stays relatively constant as you move away from the galactic centers. This change is caused by the sheer amount of dark matter that surrounds the galaxy. But why is this galaxy warped? It is also important to note that the disks of galaxies are thin and flat but not solid. It is thought that some wraps result from interactions or collisions between galaxies.  It however, is not completely known, and it is also thought that our galaxy is thought to have a small warp.