Figure 12-14 X-rays Emitted by Heated Gas An artist’s illustration of a black hole and a normal star shown in blue. Gas is being pulled away from the star and falling onto a red disk spinning around the black hole. Some of this gas is heated as it spirals toward the black hole, generating X-ray amounts of light along the way. (NASA/CXC/M. Weiss; X-ray spectrum: NASA/CXC/U. Michigan/J. Miller et al.)