X-ray/Ultraviolet composite NGC 4631
This image shows the spiral galaxy NGC 4631 as seen edge-on from NASA's Chandra X-ray Observatory and Ultraviolet Imaging Telescope (UIT). The Chandra data (shown in blue and purple) provide the first unambiguous evidence for a halo of hot gas surrounding a galaxy that is very similar to our Milky Way. The orange color in the middle of the image represents ultraviolet radiation as observed by UIT, tracing massive stars in the galaxy. 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 the understanding our own galactic environment.
(Credit: X-ray: NASA/CXC/UMass/D.Wang et al., UV: NASA/GSFC/UIT)

Scale: Image is 8.2 arcmin on a side.

Black-and-white optical image
This is an optical image of the spiral galaxy NGC 4631. The two boxes on this image represent the areas covered by the X-ray/ultraviolet and the X-ray/optical composites.
(Credit: NOAO/AURA/NSF)

Scale: Image is 8.2 arcmin on a side.

NGC 4631 Composite (3 panel)
This three-panel image puts the black-and-white optical view, the X-ray/ultraviolet composite, and the X-ray and H-alpha emission composite into context with one another.
(Credit: Left panel: NOAO/AURA/NSF Middle panel: X-ray: NASA/CXC/UMass/D.Wang et al., UV: NASA/GSFC/UIT Right panel: X-ray: NASA/UMass/D.Wang et al., Optical: NASA/HST/D.Wang et al.)

Scale: Central Region: 2.5 arcmin on a side.
Whole Galaxy: 8.2 arcmin on a side.

NGC 4631 Composite (Stacked)
This image shows the black-and-white optical view, the X-ray/ultraviolet composite, and X-ray and H-alpha emission composite as they appear when overlaid with one another.
(Credit: X-ray: NASA/CXC/UMass/D.Wang et al., Optical: NASA/HST/D.Wang et al., UV: NASA/GSFC/UIT Black&White Optical: NOAO/AURA/NSF)

Scale: Central Region: 2.5 arcmin on a side.
Whole Galaxy: 8.2 arcmin on a side.

NGC 4631 X-ray (Whole Field)
This Chandra image displays X-rays emitted by the spiral galaxy NGC 4631 in the energy range of 0.3 through 7 keV.
(Credit: NASA/CXC/UMass/D.Wang et al.)

Scale: 8.2 arcmin on a side.

NGC 4631 X-ray (Center)
This Chandra X-ray image shows the central region of NGC 4631 as seen in 0.3-0.9 keV range of the electromagnetic spectrum.
(Credit: NASA/CXC/UMass/D.Wang et al.)

Scale: 2.5 arcmin on a side.

Ultraviolet NGC 4631

This image shows the spiral galaxy NGC 4631 in ultraviolet radiation by the Ultraviolet Imaging Telescope (UIT).
(Credit: NASA/GSFC/UIT)

Chandra X-ray Image with Scale Bar

Scale bar = 30 arcsec
(Credit: X-ray: NASA/CXC/UMass/D.Wang et al., Optical: NASA/HST/D.Wang et al.)