ﻻ يوجد ملخص باللغة العربية
A comprehensive new approach is presented for deriving probability densities of physical properties characterizing lens or source that constitute an observed galactic microlensing event. While previously encountered problems are overcome, constraints from event anomalies and model parameter uncertainties can be incorporated into the estimate. Probability densities for given events need to be carefully distinguished from the statistical distribution of the same parameters among the underlying population from which the actual lenses and sources are drawn. Using given model distributions of the mass spectrum, the mass density, and the velocity distribution of Galactic disk and bulge constituents, probability densities of lens mass, distance, and the effective lens-source velocities are derived, where the effect on the distribution that arises from additional observations of annual parallax or finite-source effects, or the absence of significant effects, is shown. The presented formalism can also be used to calculate probabilities for the lens to belong to one or another population and to estimate parameters that characterize anomalies. Finally, it is shown how detection efficiency maps for binary-lens companions in the physical parameters companion mass and orbital semi-major axis arise from values determined for the mass ratio and dimensionless projected separation parameter, including the deprojection of the orbital motion for elliptical orbits. Compared to the naive estimate based on typical values, the detection efficiency for low-mass companions is increased by mixing in higher detection efficiencies for smaller mass ratios (i.e. smaller masses of the primary).
The mass of the lenses giving rise to Galactic microlensing events can be constrained by measuring the relative lens-source proper motion and lens flux. The flux of the lens can be separated from that of the source, companions to the source, and unre
We present an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are located in Galactic globular clusters. We find that in four cases some eve
We investigate the effects of the Kepler rotation of lens binaries on the binary-microlensing events towards the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). It is found that the rotation effects cannot always be neglected when
We present the analysis of the light curves of 9 high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2009-BLG-1
In this note we perform an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are located in Galactic globular clusters. We find that in four c