Where Science Meets Art
Photograph by NASA/HST/Daniel Wang, University of Massachusetts
This spattering of purples and reds is a composite of x-ray and optical images from Chandra and the Hubble Space Telescope of NGC 4631—a spiral galaxy strikingly similar to our own Milky Way. Hubble reveals gas ionized and shaped by massive stars (colored red), and Chandra detects ghostly purple and blue x-ray energy. "This image provides long-sought evidence that a spiral galaxy is not just a disk of stars," says Chandra spokesman Wallace Tucker, "but that it is enveloped in hot gas." This finding should quell debate over the presence of multimillion-degree gas within other galaxies, including our own.