Illustration of a crystal gamma-ray detector. The electrons expelled by gamma-rays act like a trigger on an alarm, letting the detector know when gamma rays are passing through. The American physicist Arthur Holly Compton discovered that gamma rays would expel electrons as they moved through a detector. The first gamma-ray satellite, Explorer XI, was launched in 1961, a year before Compton's death. The Compton Gamma Ray Observatory, launched in 1991 and still orbiting the Earth today, was named in his honor.
Most objects give off several frequencies of energy simultaneously.
Your body, for instance, glows in thermal infrared down to radio. But in order to get astronomical data about different wavelengths, scientists have to use several different types of telescopes. There is no such thing as an 'all-wave' telescope. The problem with having one telescope able to detect the entire electromagnetic spectrum lies in the differences in detection techniques. Different energy wavelengths interact with matter in different ways.