Chandra view of the halo around NGC 5746
Credit: Credit: X-ray: NASA/CXC/U. Copenhagen/K.Pedersen et al; Optical: Palomar DSS

Falling In

Spiral galaxies are believed to form in a manner similar to the stars they contain: huge clouds of gas gravitationally collapse, and swirl together forming the beautiful spiral patterns we see in our own Milky Galaxy, and others. This process has never been directly observed, but astronomers and computer modellers think that evidence of this infall should be observable as remnant hot gas halos around the galaxy. While hot halos have been observed around some spirals, those halos are associated with strong stellar winds and supernovae in star forming galaxies. But a recent Chandra image of the spiral galaxy NGC 5746 helps support galaxy formation theories. NGC 5746 does not show evidence of strong star formation, yet Chandra has detected a weak halo surrounding it. The image above is a composite of an optical image, with the X-ray halo detected by Chandra in blue.

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Page Author: Dr. Michael F. Corcoran
Last modified Friday, 20-Apr-2012 15:25:29 EDT