This Spitzer false-color image is a composite of data from the 24 micron
channel of Spitzer's multiband imaging photometer (red), and three channels
of its infrared array camera: 8 micron (yellow), 5.6 micron (blue), and 4.8
micron (green). Stars are most prominent in the two shorter wavelengths,
causing them to show up as turquoise. The supernova remnant is most
prominent at 24 microns, arising from dust that has been heated by the
supernova shock wave, and re-radiated in the infrared. The 8 micron
data shows infrared emission from regions closely associated with the
optically emitting regions. These are the densest regions being encountered
by the shock wave, and probably arose from condensations in the
surrounding material that was lost by the supernova star before it exploded.
The composite above (PIA06908, PIA06909, and PIA06910 represent views of Kepler's supernova remnant
taken in X-rays, visible light, and infrared radiation.
Each top panel in the composite above shows the entire remnant. Each color
in the composite represents a different region of the electromagnetic
spectrum, from X-rays to infrared light. The X-ray and infrared data
cannot be seen with the human eye. Astronomers have color-coded those
data so they can be seen in these images.
The bottom panels are close-up views of the remnant. In the bottom, center
image, Hubble sees fine details in the brightest, densest areas of gas.
The region seen in these images is outlined in the top, center panel.
The images indicate that the bubble of gas that makes up the supernova
remnant appears different in various types of light. Chandra reveals the
hottest gas [colored blue and colored green], which radiates in X-rays.
The blue color represents the higher-energy gas; the green, the
lower-energy gas. Hubble shows the brightest, densest gas [colored
yellow], which appears in visible light. Spitzer unveils heated dust
[colored red], which radiates in infrared light.
