Search for Isolated Black Holes: Past, Present, Future

Abstract

The critical property of a black hole is the presence of an event horizon. It may be detected only by means of a detailed study of the emission features of its surroundings. The temporal resolution of such observations has to be comparable to <em>r<sub>g </sub>/c</em>, which is in the 10<sup>−6</sup>–10 s range, depending on the mass of the black hole. At SAO RAS we have developed the MANIA hardware and software complex, based on the panoramic photon counter, and we use it in observations on the 6m telescope for searching and investigating the optical variability of various astronomical objects on time scales of 10<sup>−6</sup>–10<sup>3</sup> s. We present here the hardware and methods used for these photometric, spectroscopic and polarimetric observations, together with the principles and criteria for object selection. The list of objects includes objects with featureless optical spectra (DC white dwarfs, blazars) and long microlensing events.