Related papers: Microlensing of Circumstellar Disks
Observations of caustic-crossing galaxies at redshift $0.7<z<1$ show a wealth of transient events. Most of them are believed to be microlensing events of highly magnified stars. Earlier work predicted such events should be common near the…
We present an efficient method for computing lightcurves of an elliptical source which is microlensed by a point mass. The amplification of an extended source involves a two-dimensional integral over its surface brightness distribution. We…
The optical depth to microlensing toward M31 due to known stars in the disk of M31 itself is $\tau\sim 2\times 10^{-7}e^{-r/d}$ where $d$ is the disk scale length and $r$ is the distance along the major axis. Thus, there can be significant…
It is well known that the polarization signal in microlensing events of hot stars is larger than that of main-sequence stars. Most hot stars rapidly rotate around their stellar axes. The stellar rotation makes ellipticity and…
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 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…
The current modelling of single microlensing light curves neglects the possibility that only a fraction of the light is due to the lensed star, the remaining being due to a close, unresolved blend, which may be related or unrelated to the…
The observed spectra of the microlensed sources towards the Galactic bulge may be used as a tool for studying the kinematics and extinction effects in the Galactic bulge. In this paper, we first investigate the expected distribution of the…
This paper presents first results on the line profile shapes from a circumstellar envelope in bulk motion as modified by a microlensing event. Only geometrically and optically thin spherical shells in uniform expansion or rotation are…
The magnification induced by gravitational microlensing is sensitive to the size of a source relative to the Einstein radius, the natural microlensing scale length. This paper investigates the effect of source size in the case where the…
Multiply-imaged quasars and AGNs observed in the mid-infrared (MIR) range are commonly assumed to be unaffected by the microlensing produced by the stars in their lensing galaxy. In this paper, we investigate the validity domain of this…
We consider small-scale spheroidal clusters of weakly interacting massive particles in our Galaxy as non-compact gravitational microlenses and predict the appearance of caustics in the plane of a lensed source. The crossing of these…
Recent observations of lensed galaxies at cosmological distances have detected individual stars that are extremely magnified when crossing the caustics of lensing clusters. In idealized cluster lenses with smooth mass distributions, two…
Under the current microlensing planet search strategy of monitoring events caused by stellar-mass lenses, only planets located within a narrow region of separations from central stars can be effectively detected. However, with the dramatic…
The gravitational microlensing as a unique astrophysical tool can be used for studying the atmosphere of stars thousands of parsec far from us. This capability results from the bending of light rays in the gravitational field of a lens…
We propose an observational test that can break the degeneracy of two main classes of microlensing models to the Magellanic Clouds: (a) the lenses are located in the Galactic halo, and (b) the lenses are located in the LMC disk. The source…
We explore the detection condition of a wide-separation planet through the perturbation induced by the planetary caustic for various microlensing parameters, especially for the size of the source stars. By constructing the fractional…
A new window to observing individual stars and other small sources at cosmological distances was opened recently, with the detection of several caustic-crossing events in galaxy cluster fields. Many more such events are expected soon from…
Effects of macro-and microlensing on the spatial and temporal characteristics of images of remote sources, observed through the inner regions of lensing galaxies are discussed. A particular attention was given to the case, when microlenses,…
The simple physics of microlensing provides a well-understood tool with which to probe the atmospheres of distant stars in the Galaxy and Local Group with high magnification and resolution. Recent results in measuring stellar surface…