Probability distributions for the magnification of quasars due to microlensing

Gravitational microlensing can magnify the flux of a lensed quasar considerably and therefore possibly influence quasar source counts or the observed quasar luminosity function. We present a large number of distributions of magnification probabilities due to gravitational microlensing for finite sources, with a reasonable coverage of microlensing parameter space (i. e. , surface mass density, external shear, mass spectrum of lensing objects). These probability distributions were obtained from smoothing two-dimensional magnification patterns with Gaussian source profiles. We explored different source sizes ranging from ~10¹4^ cm to 5 x 10¹6^ cm (for typical lens and source distances). The probability distributions show a large variety of shapes. We present coefficients of fitted slopes for large magnifications. The data for the probability distributions are accessible in digital form.