Autoionization refers to a process in which an atom or molecule absorbs energy and subsequently emits an electron, resulting in the formation of an ion. This phenomenon occurs when an electron in a high-energy state in an atom or molecule spontaneously moves to a lower energy state, releasing excess energy as an electron. Autoionization is commonly studied in the field of atomic and molecular physics, as it plays a crucial role in processes such as photoionization, collisional ionization, and other types of ionization processes. Researchers study autoionization to gain a better understanding of the electronic structure and dynamics of atoms and molecules, as well as to develop applications in various fields such as spectroscopy, laser physics, and plasma physics.