Observational Characteristics of Giant Pulses and Related Phenomena

Evidence now exists that at least 14 pulsars emit distinctive pulses that are stronger and narrower than the average pulse. I review observations of these pulses in an effort to determine which sources share a common emission-mechanism. All of the giant pulses emitted by millisecond pulsars have power-law energy-statistics and occur in narrow phase-windows that coincide with those of X-ray emission. The giant pulses of millisecond pulsars therefore probably originate from a single process. They are always unresolved at microsecond timescales, and therefore the emission is likely to arise from the superposition of a small number of nano-shots. Most are actually very weak when compared to the average pulse. They are only ``giant'' when examined in terms of their ultra-high brightness temperatures. Giant pulses from other sources have a variety of widths, shapes, and energy distributions. The giant pulses from the Crab pulsar have intrinsic sub-microsecond timescales like the giant pulses of the millisecond pulsars, and therefore probably originate from the same mechanism. Other phenomena, such as giant micro-pulses from young pulsars and giant pulses from slow pulsars have not been shown to have such short timescales. These phenomena likely arise from other mechanisms.