A race of aliens exists on a distant planet whose biological functioning depends on absorbing a specific type of energy. They have what is essentially an antenna through which they passively absorb the energy. However, it is possible for them to absorb "tainted" energy, which has a negative effect. A little will make them sick, a moderate amount will cause them pain and render them unconscious, and a large amount will cause their antenna to literally explode, leaving them in excruciating pain for the final minutes or hours of their lives.
These aliens are also telepathic. However, unlike, for example, Betazoids, they do not simply "speak" a verbal language into each other's minds. Instead, they are capable of transmitting hundreds of images, sounds, and emotions to each other instantaneously. This is their primary means of communication.
What type of energy are they absorbing? What makes it "clean" or "tainted", and how is it changed between the two states? Given your answer and the information above and below, what other traits would the aliens possess?
- Telepathy may or may not operate through the same antenna that absorbs energy. In either case, the aliens are still capable of telepathy after tainted energy causes their antenna to explode, assuming they are disciplined enough to focus through the pain.
- Each alien has one antenna. It is shaped like a funnel on the top of their head and curves outward, almost to the point of touching itself and forming a taurus.
- The nature of how their bodies make use of absorbed energy means that they don't require sleep.
- They do have mouths, but biologically speaking, they don't need them. They can eat, but they don't need to, and even if they do, they still require absorbed energy. They have vocal cords, but no verbal language. They can mimic any sound they hear and enjoy using their "voices" as musical instruments.
- The type of energy does not have to be something that does or could exist, so long as its properties are explainable and predictable. However, some resemblance to known principles of physics is a plus.
- Humans will eventually discover this energy source after colonizing another planet (not the aliens' home world). The energy they produce will be tainted. An alien engineer will be able to modify their energy source. After he does, it will not produce any energy at all unless a "filter" is in place to keep the energy clean.
- In the absence of a filter, an alien can keep the power source working by allowing the energy to pass through his own body. (Note that this is not true filtration, as their bodies can't filter out tainted energy they absorb. Rather, their bodies are in some way rearranging, modifying or amplifying the energy in a way that baffles the human engineers.)
- Humans are incapable of receiving telepathic communication from the aliens. However, devices can be made that can record the images and sounds.
- A material exists which blocks the energy, both clean and tainted. The aliens can use it for protection, but not indefinitely (as they can't absorb clean energy while using it).
- While an untreated exploding antenna is always fatal to an adult, an infant or very young child may be able to heal enough to survive, but he will never be at full strength or health. Both children and adults can be fully healed by a medical procedure.
- The aliens possess wings. Other than that and the other conditions listed, they appear more or less humanoid.