MASS ESTIMATES OF DARK MATTER BODIES FROMTHE TIMESCALE OF QUASAR VARIATION

摘要

This paper sets out to measure the timescale of quasar variability with a viewto new understanding of the size of accretion discs in active galactic nuclei. Wecombine data from two large scale monitoring programmes to obtain Fourierpower spectra of light curves covering nearly three orders of magnitude infrequency in blue and red passbands. If the variations are interpreted as dueto gravitational microlensing, then timescale measurements in the observer'sframe imply a minimum mass for the microlensing bodies of around 0.4Mo.