Related papers: Microlensing of an Elliptical Source by a Point Ma…
We consider microlensing of an elliptical source crossing a fold caustic. We derive a simple expression for the light curve of a source with uniform surface brightness that is accurate to third order in the ellipticity e (yielding errors of…
Extended source effects can be seen in gravitational lensing events when sources cross critical lines. Those events probe the stellar intensity profile and could be used to measure limb darkening coefficients to test stellar model…
The goal of this paper is to provide a numerically fast and stable description for the microlensing amplification of an extended source (either uniform or limb-darkened) that holds in any amplification regime. We show that our method of…
Microlensing promises to be a powerful tool for studying distant galaxies and quasars. As the data and models improve, there are systematic effects that need to be explored. Quasar continuum and broad-line regions may respond differently to…
The method devised by Lewis et al. (1993) for calculating the light curve of a microlensed point source is expanded to two dimensions to enable the calculation of light curves of extended sources. This method is significantly faster than…
We present a method to compute the magnification of a finite source star lensed by a triple lens system based on the image boundary (contour integration) method. We describe a new procedure to obtain continuous image boundaries from…
We investigate the feasibility of reconstructing the radial intensity profile of extended stellar sources by inverting their microlensed light curves. Using a simple, linear, limb darkening law as an illustration, we show that the intensity…
We investigate the microlensing effects on a source star surrounded by a circumstellar disk, as a function of wavelength. The microlensing light curve of the system encodes the geometry and surface brightness profile of the disk. In the…
We have developed a code to compute multi-colour microlensing lightcurves for extended sources, including the effects of limb darkening and photospheric star spots as a function of spot temperature, position, size and lens trajectory. Our…
The contouring methods described by Lewis et al. (1993) and Witt (1993) are very efficient and elegant for obtaining the magnification of a point source moving along a straight track in the source plane. The method is, however, not very…
The availability of a robust and efficient routine for calculating light curves of a finite source magnified due to bending its light by the gravitational field of an intervening binary lens is essential for determining the characteristics…
During microlensing events with a small impact parameter, the amplification of the source flux is sensitive to the surface brightness distribution of the source star. Such events provide a means for studying the surface structure of target…
We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…
We can survey an Ellis wormhole which is the simplest Morris-Thorne wormhole in our galaxy with microlensing. The light curve of a point source microlensed by the Ellis wormhole shows approximately $4\%$ demagnification while the total…
There is increasing interest in extended source effects in microlensing events, as probes of the unresolved sources. Previous work has either presumed a uniform source, or else required an approximate or numerical treatment of the…
If gravitational microlensing occurs in a binary-source system, both source components are magnified, and the resulting light curve deviates from the standard one of a single source event. However, in most cases only one source component is…
In a line caustic crossing microlensing event, the caustic line moving across the surface of the source star provides a direct method to measure the integrated luminosity profile of the star. Combined with the enormous brightening at the…
In the smooth mass distribution model, the critical curve represents a line with magnification divergence on the image plane in a strong gravitational lensing system. Considering the microlensing effects caused by discrete masses, the…
We explore the sensitivity of two-point-mass gravitational microlensing to the extended nature of the source star, as well as the related sensitivity to its limb darkening. We demonstrate that the sensitive region, usually considered to be…
Recent surveys monitoring millions of light curves of resolved stars in the LMC have discovered several microlensing events. Unresolved stars could however significantly contribute to the microlensing rate towards the LMC. Monitoring…