Chandra Release - July 19, 2001

Visual Description: NGC 4631

The image is a multiwavelength astronomical image of a spiral galaxy named NGC 4631. This galaxy is located in the constellation Canes Venatici, approximately 25 million light-years away from Earth.  The image features red, white and blue colors.  The overall structure of the galaxy can be described as a spiral pattern, reminiscent of a pinwheel. This image shows the central region of the spiral galaxy as seen edge-on from NASA's Chandra X-ray Observatory  and Hubble Space Telescope. The Chandra data (shown in deep blue, almost purple) provide the first unambiguous evidence for a halo of hot gas surrounding a galaxy that is very similar to our Milky Way. The arm-like structure stretching across the middle of the image and the extended faint filaments (colored in red-orange) represent the observation from Hubble that reveals giant bursting bubbles created by clusters of massive stars. Scientists have debated for over 40 years whether the Milky Way has an extended corona, or halo, of hot gas. Observations of NGC 4631 and similar galaxies provide astronomers with an important tool in understanding our own galactic environment.