The images below have all been made using SAOImageDS9. They can be interactively created from the DS9 GUI or from the command line as shown.
ds9 -rgb -red -url http://ds9.si.edu/download/data/crab_2mass.fits -scale mode 99 -green -url http://ds9.si.edu/download/data/crab_chandra.fits -scale linear -blue -url http://ds9.si.edu/download/data/crab_dss2.fits -scale linear
The Crab Nebula is the remnant of a supernova explosion that was seen on Earth in 1054 AD. It is 6000 light years from Earth. At the center of the bright nebula is a rapidly spinning neutron star, or pulsar that emits pulses of radiation 30 times a second.
This RGB composite image is composed from data at three different wave lengths. Infared data from 2MASS displayed in red, X-Ray data from Chandra displayed in green, and optical data from DSS2 displayed in blue.
Data Credits: NASA/2MASS/CXC/DSS2
ds9 -rgb -red -url http://ds9.si.edu/download/data/casa_low.fits -log -smooth -green -url http://ds9.si.edu/download/data/casa_mid.fits -log -smooth -blue -url http://ds9.si.edu/download/data/casa_high.fits -log -smooth
This RGB composite image shows a beautiful X-ray view of Cassiopeia A (Cas A), a supernova remnant located in our Galaxy about 11,000 light years away. These are the remains of a massive star that exploded about 330 years ago, as measured in Earth's time frame. At the center of the image is a neutron star, an ultra-dense star created by the supernova.
In this RGB composite the low energy X-rays from Chandra are shown in red, mid range energy X-rays are shown in green and high energy X-rays are shown in blue.
Data Credits: NASA/CXC
Eagle Nebula "Pillars of Creation"
ds9 -rgb -red -url http://ds9.si.edu/download/data/673nmos.fits -zscale -green -url http://ds9.si.edu/download/data/656nmos.fits -zscale -blue -url http://ds9.si.edu/download/data/502nmos.fits -zscale -rotate 270 -zoom to fit
At the center of the Eagle Nebula, towers of dust and gas form the stunning feature known as the 'Pillars of Creation'.
Imaged by Hubble's WFPC2 camera, this RGB composite image is composed of lower frequency optical data in red, mid range frequency optical data in green, and higher frequency optical data in blue.
Data Credits: NASA/STSci