Consolidation has been the general rule for many of our industries. That is, at inception any given industry is composed of many manufacturers. With time consolidation occurs. The automobile industry started at the very end of the nineteenth century and subsequently grew to include hundreds of different brands (or marques). Over the course of time, many of these manufacturers failed and some merged to become larger entities. (Studebaker, anyone?) Finally, as the industry becomes mature, only a few large manufacturers are left. Ford now not only encompasses Lincoln and Mercury, it also includes Jaguar, Volvo, Land Rover and a controlling interest in Mazda. So it has been in other industries such as personal computers and telecommunications. And so it is, it seems, with galaxies.
Apparently, and without prior recognition by scientists, our own Milky Way is being merged with another galaxy.
WASHINGTON, Jan. 9 – A previously unrecognized galaxy appears to be merging with the Milky Way, bringing hundreds of thousands of stars into our home galaxy that no one has noticed until now, astronomers said Monday. …
Robert H. Lupton of Princeton University told a meeting of the American Astronomical Society that the large, faint collection of stars rises almost perpendicular to the flat, spiral disk of the Milky Way. The most likely interpretation of the structure, the astronomer said, is that it is a dwarf galaxy that has been merging with our galaxy.
Talk about mergers, this makes Ford’s activities pale into insignificance. The Milky Way includes some 200 billion stars and measures 100,000 lightyears across.
The discovery was made through the Sloan Digital Sky Survey, in operation for more than 5 years. Link From the Survey’s about page:
The Sky Survey will systematically map one-quarter of the entire sky, producing a detailed image of it and determining the positions and absolute brightnesses of more than 100 million celestial objects. It will also measure the distance to a million of the nearest galaxies, giving us a three-dimensional picture of the universe through a volume one hundred times larger than that explored to date. The Sky Survey will also record the distances to 100,000 quasars, the most distant objects known, giving us an unprecedented hint at the distribution of matter to the edge of the visible universe.
By systematically and sensitively observing such a large fraction of the sky, the Sky Survey will have a significant impact on astronomical studies as diverse as the large-scale structure of the universe, the origin and evolution of galaxies, the relation between dark and luminous matter, the structure of our own Milky Way, and the properties and distribution of the dust from which stars like our sun were created. It will represent a new reference point, a field guide to the universe at the millenium, which will be used by scientists for decades to come.
The project is being done through the cooperation of several groups using the telescope at Apache Point Observatory in Sunspot, New Mexico.
