What is a Radio Transient?
The SKA will be able to survey the sky at a rate faster than any survey telescope that has ever existed. It will perform Continuum Surveys looking at vast swathes of the radio sky from the Southern Hemisphere, making a detailed map as the thousands of telescopes work in unison. During the course of these continuum surveys however, so called transient events will occur.
Transient events when we think about galactic scales over which the SKA will be looking at the sky are events which change rapidly, unleashing typically vast amounts of energy as they do so. Events such as Gamma Ray Bursts or Supernovae. Typically these events are only visible for short periods of time, sometimes in multiple wavelengths across the electromagnetic spectrum.
Transient events such as GRB (Gamma Ray Bursts) are some of the most violent events in the Universe. Unleashing huge amounts of energy, they can be detected out for many billions of light years. The SKA’s survey capability will be able to detect these, allowing the SKA to perform more targeted observations of the specific events, and also alert other telescopes in a range of frequencies to also observe them.
Already under way with SKA pathfinder and precursor telescopes such as MeerKat in South Africa, the ThunderKAT project (The Hunt for Dynamic and Explosive Radio Transients with MeerKAT), these transient surveys will form a core function of the SKA when fully operational
Exploration of the transient Universe is an exciting and fast-emerging area within radio astronomy. Known transient phenomena range in time scales from below even one nanosecond through to several years, which is still a short period of time in the cosmological scale of things
The shorter the better
Of particular interest are very short transient events the detections of which involve considerable signal processing and data management challenges, which will be perfectly suited to the capabilities of the SKA
With its wider field of view and higher sensitivity, the SKA, holds great potential to revolutionise this relatively new and exciting field, thereby opening up incredible new science avenues in astrophysics.