The Role of Scan Statistics in High-Energy Astrophysics

Astronomers often face with the problem of recognizing activity periods of celestial sources. Once an activity period is found during the operations of the observing telescope, quasi-simultaneous multiwavelength monitor of the celestial source activity is often performed through alert dissemination and target-of-opportunity (ToO) programs. In some other cases, astronomers are interested in studying the physical characteristics of several activity periods of a single celestial source or of a class of sources of interest. The current generation of x- and gamma-ray telescopes usually provides the arrival time of collected photons; also some extremely fast optical instrumentation is able to record photon-by-photon events, and it has been a couple of years now that fast optical sensitive planes are available at the loci of 1–4 m class telescopes to the astronomers community on a regular basis during the biannual cycles of observations. In spite of this, scan statistics were not applied to solve the problems of recognizing activity periods of celestial sources. In this chapter, we address the astrophysical problem in a general way, and we identify some fields for which scan statistics will provide improvement to the current knowledge of astrophysical sources.