Gravitational Microlensing near Caustics. I. Folds
نویسندگان
چکیده
منابع مشابه
Gravitational Microlensing Near Caustics I: Folds
We study the local behavior of gravitational lensing near fold catastrophes. Using a generic form for the lensing map near a fold, we determine the observable properties of the lensed images, focusing on the case when the individual images are unresolved, i.e., microlensing. Allowing for images not associated with the fold, we derive analytic expressions for the photometric and astrometric beha...
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We present a rigorous, detailed study of the generic, quantitative properties of gravitational lensing near cusp catastrophes. Concentrating on the case when the individual images are unresolved, we derive explicit formulas for the total magnification and centroid of the images created for sources outside, on, and inside the cusped caustic. We obtain new results on how the image magnifications ...
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Calculations are presented detailing the gravitational lens diffraction due to the steep brightness gradient of the limb of a stellar source. The lensing case studied is the fold caustic crossing. The limb diffraction signal greatly exceeds that due to the disk as a whole and should be detectable for white dwarf sources in our Galaxy and its satellites with existing telescopes. Detection of thi...
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To maximize the number of planet detections, current microlensing follow-up observations are focusing on high-magnification events which have a higher chance of being perturbed by central caustics. In this paper, we investigate the properties of central caustics and the perturbations induced by them. We derive analytic expressions of the location, size, and shape of the central caustic as a fun...
متن کاملMicrolensing of Elliptical Sources by Fold Caustics
We consider the problem of an elliptical background source crossing a linear gravitational lensing fold caustic. We derive a simple expression for the light curve of a source with a uniform surface brightness that is accurate to third order in the ellipticity e (yielding brightness errors of . 1% for e . 0.3). We then consider caustic crossings of a rotating star, an oblate giant extrasolar pla...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2002
ISSN: 0004-637X,1538-4357
DOI: 10.1086/341063