Chandra Release - December 10, 2007

Visual Description: Whirlpool Galaxy (M51)

 A composite image of the Whirlpool Galaxy (also known as M51) is shown, which features a dramatic spiral galaxy. The dominant colors in this image are purple and pink with bright wisps of red and blue. The structure of the galaxy is a strong spiral shape, with a very large bright spot in its middle. X-ray data from NASA's Chandra X-ray Observatory reveals point-like sources (in purple) scattered throughout that are black holes and neutron stars in binary star systems. Chandra also detects a soft diffuse glow (in purple) of hot gas that permeates the space between the stars. Optical data from the Hubble Space Telescope (in green) and infrared emission from the Spitzer Space Telescope (in red) both highlight the long lanes in the spiral arms that consist of stars and gas laced with dust. A view of M51 with the GALEX telescope shows hot, young stars that produce lots of ultraviolet energy (blue dots and streaks throughout). The textbook spiral structure of the object is thought to be the result of an interaction M51 is experiencing with its close galactic neighbor, NGC 5195, which is seen just at the top as another large bright white spot with some areas of green. Some simulations suggest M51's sharp spiral shape was partially caused when NGC 5195 passed through its main disk about 500 million years ago. This gravitational tug of war may also have triggered an increased level of star formation in M51.