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Related papers: Microlensing of an Elliptical Source by a Point Ma…

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We study the gravitational microlensing of various static and spherically symmetric non-singular black holes (and horizonless, non-singular compact objects of similar size). For pointlike sources we extend the parametrized post-Newtonian…

General Relativity and Quantum Cosmology · Physics 2026-02-05 Jens Boos , Hao Hu

Extended dark matter (DM) substructures may play the role of microlenses in the Milky Way and in extragalactic gravitational lens systems (GLSs). We compare microlensing effects caused by point masses (Schwarzschild lenses) and extended…

Astrophysics of Galaxies · Physics 2022-09-07 E. Fedorova , V. M. Sliusar , V. I. Zhdanov , A. N. Alexandrov , A. Del Popolo , J. Surdej

Gravitational microlensing is a new technique for studying the surfaces of distant stars. A point mass lens, usually a low-mass star from the disk, will typically resolve the surface of a red giant in the Galactic bulge, as well as amplify…

Astrophysics · Physics 2007-05-23 Dimitar D. Sasselov

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…

Astrophysics · Physics 2015-06-24 Shude Mao , Hans J. Witt

We have worked out simple analytical formulae that accurately approximate the relationship between the position of the source with respect to the lens center and the amplification of the images, hence the lens cross section, for realistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Lapi , M. Negrello , J. Gonzalez-Nuevo , Z. -Y. Cai , G. De Zotti , L. Danese

The extended source effect on microlensing magnification is non-negligible and must be taken into account for in an analysis of microlensing. However, the evaluation of the extended source magnification is numerically expensive because it…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 Sunao Sugiyama

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…

Instrumentation and Methods for Astrophysics · Physics 2022-08-15 Ashish Kumar Meena , Ofir Arad , Adi Zitrin

We present an algorithm to estimate fast and accurate depth maps from light fields via a sparse set of depth edges and gradients. Our proposed approach is based around the idea that true depth edges are more sensitive than texture edges to…

Computer Vision and Pattern Recognition · Computer Science 2021-07-08 Numair Khan , Min H. Kim , James Tompkin

We present an algorithm capable of detecting diffuse, dim sources of any size in an astronomical image. These sources often defeat traditional methods for source finding, which expand regions around points of high intensity. Extended…

Instrumentation and Methods for Astrophysics · Physics 2016-01-05 T. Butler-Yeoman , M. Frean , C. P. Hollitt , D. W. Hogg , M. Johnston-Hollitt

We introduce a new method of searching for and characterizing extra-solar planets. We show that by monitoring the center-of-light motion of microlensing alerts using the next generation of high precision astrometric instruments the…

Astrophysics · Physics 2009-10-31 Neda Safizadeh , Neal Dalal , Kim Griest

The large number of microlensing events discovered towards the Galactic Bulge bears the promise to reconstruct the stellar mass function. The more interesting issue concerning the mass function is certainly to probe its low mass end.…

Astrophysics · Physics 2009-10-31 C. Alard

We present new methods for uniformly sampling the solid angle subtended by a disk. To achieve this, we devise two novel area-preserving mappings from the unit square $[0,1]^2$ to a spherical ellipse (i.e. the projection of the disk onto the…

We discuss distortion in microlensing-induced light curves which are considered to be curves due to single-point-mass lenses at a first glance. As factors of the distortion, we consider close binary and planetary systems, which are the…

Astrophysics · Physics 2009-10-31 Kohkichi Konno , Yasufumi Kojima

Plasma lensing is the refraction of low-frequency electromagnetic rays due to free electrons in the interstellar medium. Although the phenomenon has a distinct similarity to gravitational lensing, particularly in its mathematical…

Astrophysics of Galaxies · Physics 2019-08-07 Xinzhong Er , Adam Rogers

Microlensing of extended stellar sources in the LMC and Galaxy by low mass lenses can produce variable polarisation. The characteristics of the polarisation and flux profiles can provide considerable information about the lens geometry, and…

Astrophysics · Physics 2015-06-24 J. F. L. Simmons , A. M. Newsam , J. P. Willis

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…

Astrophysics · Physics 2009-11-11 Geraint F. Lewis , Rodrigo Gil-Merino

Gravitational Microlensing has been used as a powerful tool for astrophysical studies and exoplanet detections. In the gravitational microlensing, we have two images with negative and positive parities. The negative-parity image is a…

Earth and Planetary Astrophysics · Physics 2016-05-11 Sohrab Rahvar

Recent discussion of the effects of finite source size on high magnification microlensing events due to MACHOs motivates a study into the feasibility of observing such effects and extracting the source radius. Simulated observations are…

Astrophysics · Physics 2009-10-28 Eric Peng

In this paper, we investigate the color changes of gravitational microlensing events caused by the two different mechanisms of differential amplification for a limb-darkened extended source and blending. From this investigation, we find…

Astrophysics · Physics 2009-10-31 Cheongho Han , Seong-Hong Park , Jang-Hae Jeong

We present a fast algorithm to produce light curves of distant stars undergoing microlensing near critical curves. The need of these type of algorithms is motivated by recent observations of microlensing events of distant stars at high…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 J. M. Diego