Finite-source and finite-lens effects in astrometric microlensing
نویسندگان
چکیده
منابع مشابه
Finite Source Effects in Microlensing Events
The computation of the magnification of a finite source by an arbitrary gravitational lens can be reduced from a two-dimensional to a one-dimensional integral using a generalization of Stoke’s theorem. For a large source lensed by a planetarysystem whose planet lies at the position where one of the two images would be in the absence of a planet, the integral can be done analytically. If the pla...
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Extended source size effects have been detected in photometric monitoring of gravitational microlensing events. We study similar effects in the centroid motion of an extended source lensed by a point mass. We show that the centroid motion of a source with uniform surface brightness can be obtained analytically. For a source with circularly symmetric limb-darkening profile, the centroid motion c...
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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 evaluating the amplification can be implemented into a light-curve fitting routine using the Levenberg-Marquardt algorithm. We compare the accuracy and computat...
متن کاملAstrometric Microlensing of Stars
Due to dramatic improvements in the precision of astrometric measurements, the observation of light centroid shifts in observed stars due to intervening massive compact objects (‘astrometric microlensing’) will become possible in the near future. Upcoming space missions, such as SIM and GAIA, will provide measurements with an accuracy of 4–60 μas depending on the magnitude of the observed stars...
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It has been recognized that the arc statistics of gravitational lensing is a useful probe of the density profile of clusters of galaxies. We examine several systematic effects which are important in predicting the number of arcs, with particular attention to the difference between tangential and radial arcs. First we derive an analytic expression of the cross section for radial arcs taking acco...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2010
ISSN: 0035-8711
DOI: 10.1111/j.1365-2966.2010.17049.x