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Many synoptic surveys are observing large parts of the sky multiple times. The resulting lightcurves provide a wonderful window to the dynamic nature of the universe. However, there are many significant challenges in analyzing these light…

Applications · Statistics 2016-02-04 Julian Faraway , Ashish Mahabal , Jiayang Sun , Xiaofeng Wang , Yi , Wang , Lingsong Zhang

Time-delay cosmography in strongly lensed quasars offer an independent way of measuring the Hubble constant, $H_0$. However, it has been proposed that the combination of microlensing and source-size effects, also known as microlensing time…

Astrophysics of Galaxies · Physics 2021-03-24 J. H. H. Chan , K. Rojas , M. Millon , F. Courbin , V. Bonvin , G. Jauffret

We present an extended optical monitoring of the quadruply-imaged gravitationally lensed quasar QSO 2237+0305, the Einstein Cross, including observations from different observatories in both hemispheres and using a new photometric…

The central regions of the gravitationally lensed quasar Q2237+0305 can be indirectly resolved on nano-arcsecond scales if viewed spectrophotometricly during a microlensing high magnification event (HME). Q2237+0305 is currently being…

Astrophysics · Physics 2009-10-31 J. S. B. Wyithe , E. L. Turner , R. L. Webster , E. Agol

Microlensing in Q2237+0305 between 1985 and 1995 (eg. Irwin et al. 1989; Corrigan et al. 1991; Ostensen et al. 1996) has been interpreted in two different ways; as microlensing by stellar mass objects of a continuum source having dimensions…

Astrophysics · Physics 2009-10-31 J. S. B. Wyithe , R. L. Webster , E. L. Turner

We define a second-order moment of the observational differential microlensing curves that can be used to impose constraints on physical properties of lensed quasars. We show that this quantity is sensitive both to variations in the source…

Astrophysics of Galaxies · Physics 2021-05-11 Eduardo Guerras , Xinyu Dai , Evencio Mediavilla

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…

Astrophysics · Physics 2009-11-07 Eric Agol

Several macrolensed systems exhibit photometric variability consistent with microlensing due to objects of stellar mass located in the lens. The degree of microlensing amplification is dependent upon the size of the source, with smaller…

Astrophysics · Physics 2016-08-30 G. F. Lewis , M. J. Irwin , P. C. Hewett

Gravitationally lensed quasars offer a unique opportunity to study cosmological and extragalactic phenomena, using reliable light curves of the lensed images. This requires accurate deblending of the quasar images, which is not trivial due…

Instrumentation and Methods for Astrophysics · Physics 2025-04-24 Favio Neira , Frédéric Courbin , Frédéric Dux , Georgios Vernardos

Quasar microlensing can be used to constrain important astrophysical properties, such as the accretion disk size and the amount of stars in the lensing galaxy. The associated brightness variations over time, in particular high magnification…

Astrophysics of Galaxies · Physics 2025-09-09 Favio Neira , Timo Anguita , Georgios Vernardos

We analyze the lightcurve of the microlensing event OGLE-2003-BLG-175/MOA-2003-BLG-45 and show that it has two properties that, when combined with future high resolution astrometry, could lead to a direct, accurate measurement of the lens…

Astrophysics · Physics 2009-11-10 H. Ghosh

It is demonstrated that the 1988-90 microlensing events in image A of Q2237+0305 reported by Racine (1992) do not exclude microlensing models with very low average mass, making the source radius larger than the projected Einstein radius…

Astrophysics · Physics 2007-05-23 S. V. H. Haugan

We present a method for computing the probability distribution of microlensed light curve derivatives both in the case of a static lens with a transverse velocity, and in the case of microlensing that is produced through stellar proper…

Astrophysics · Physics 2009-10-31 J. S. B. Wyithe , R. L. Webster , E. L. Turner

A detailed description of the apparent light curves of microlensed SNe Ia as extended and expanding sources is presented. We show that microlensing amplification can have significant effects on supernova observation. A model light curve is…

Astrophysics · Physics 2007-05-23 Hamed Bagherpour , R. Kantowski , David Branch , Dean Richardson

A fast and practical method is described for calculating the microlensed flux variance of an arbitrary source by uncorrelated stars. The required inputs are the mean convergence and shear due to the smoothed potential of the lensing galaxy,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jeremy Goodman , Ai-Lei Sun

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…

Astrophysics · Physics 2009-10-30 M. A. Hendry , I. J. Coleman , N. Gray , A. M. Newsam , J. F. L. Simmons

In quasars which are lensed by galaxies, the point-like images sometimes show sharp and uncorrelated brightness variations (microlensing). These brightness changes are associated with the innermost region of the quasar passing through a…

High Energy Astrophysical Phenomena · Physics 2016-04-08 Mihai Tomozeiu , Irshad Mohammed , Manuel Rabold , Prasenjit Saha , Joachim Wambsganss

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…

General Relativity and Quantum Cosmology · Physics 2018-05-01 Naoki Tsukamoto , Yungui Gong

We introduce a method to constrain the characteristic angular size of the brightest cosmic-ray sources observed above 57 \times 1018 eV. By angular size of a source, we mean the effective angular extent over which cosmic-rays from that…

High Energy Astrophysical Phenomena · Physics 2011-09-28 Patrick Younk

High amplification events (HAEs) are common phenomena in extragalactic gravitational lens systems (GLSs), where the multiple images of a distant quasar are observed through a foreground galaxy. There is a considerable brightness…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-03 A. N. Alexandrov , V. M. Sliusar , V. I. Zhdanov