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Related papers: Luminosity variation in (de)focusing microlensing

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In this paper, we investigate the influence of the plasma surrounding the gravitational lens on the effect of microlensing. In presence of plasma around the lens, the deflection angle is determined by both the gravitational field of the…

General Relativity and Quantum Cosmology · Physics 2020-01-01 Oleg Yu. Tsupko , Gennady S. Bisnovatyi-Kogan

We investigate gravitational microlensing of point-like lenses surrounded by diffuse gas clouds. Besides gravitational bending, one must also consider refraction and absorption phenomena. According to the cloud density, the light curves may…

Astrophysics · Physics 2009-11-07 V. Bozza , Ph. Jetzer , L. Mancini , G. Scarpetta

If a source star is gravitationally microlensed by a multiple lens system, the resulting light curve can have significant deviations from the standard form of a single lens event. The chance to produce significant deviations becomes…

Astrophysics · Physics 2009-11-07 Cheongho Han

If a gravitational microlensing event is caused by a widely separated binary lens and the source approaches both lens components, the source flux is successively magnified by the individual lenses: double microlensing events. If events are…

Astrophysics · Physics 2009-11-07 Cheongho Han , Byeong-Gon Park , Wonyong Han , Young Woon Kang

The detection of microlensing events from stars in the Large Magellanic Cloud and in the Galactic bulge raise important constraints on the distribution of dark matter and on galactic structure, although some events may be due to a new type…

Astrophysics · Physics 2020-11-25 David Valls-Gabaud

If a microlensing event is caused by a star, the event can exhibit change in color due to the light from the lens. In the previous and current lensing surveys, the color shift could not be used to constrain the lens population because the…

Astrophysics · Physics 2009-11-13 Byeong-Gon Park , Cheongho Han

Foundations of standard theory of microlensing are described, namely we consider microlensing stars in Galactic bulge, the Magellanic Clouds or other nearby galaxies. We suppose that gravitational microlenses lie between an Earth observer…

Astrophysics · Physics 2007-05-23 A. F. Zakharov

The gravitational field of a galaxy can act as a lens and deflect the light emitted by a more distant object such as a quasar. Strong gravitational lensing causes multiple images of the same quasar to appear in the sky. Since the light in…

Instrumentation and Methods for Astrophysics · Physics 2017-10-06 Hyungsuk Tak , Kaisey Mandel , David A. van Dyk , Vinay L. Kashyap , Xiao-Li Meng , Aneta Siemiginowska

It is estimated that a star brighter than visual magnitude 17 is undergoing a detectable gravitational microlensing event, somewhere on the sky, at any given time. It is assumed that both lenses and sources are normal stars drawn from a…

Astrophysics · Physics 2009-10-30 Robert J. Nemiroff

Gravitational lensing allows us to probe the structure of matter on a broad range of astronomical scales, and as light from a distant source traverses an intervening galaxy, compact matter such as planets, stars, and black holes act as…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-09 Hugh Garsden , Geraint F. Lewis

When traveling from their source to the observer, gravitational waves can get deflected by massive objects along their travel path. When the lens is massive enough and the source aligns closely with the line-of-sight to the lens, the wave…

General Relativity and Quantum Cosmology · Physics 2022-12-28 Justin Janquart , Anupreeta More , Chris Van Den Broeck

The bending of lightrays by the gravitational field of a ``lens'' that is moving relative to the observer is calculated within the approximation of weak fields, small angles and thin lenses. Up to first order in $v/c$ -- and assuming the…

Astrophysics · Physics 2009-11-07 Simonetta Frittelli

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

As the gravitational wave detector network is upgraded and the sensitivity of the detectors improves, novel scientific avenues open for exploration. For example, tests of general relativity will become more accurate as smaller deviations…

General Relativity and Quantum Cosmology · Physics 2024-12-05 Mick Wright , Justin Janquart , Nathan K. Johnson-McDaniel

Point lens microlensing events with impact parameter close to the source stellar radius allow the observer to study the surface brightness profile of the lensed source. We have examined the effect of photospheric star spots on multicolour…

Astrophysics · Physics 2009-11-07 M. A. Hendry , H. M. Bryce , D. Valls-Gabaud

We investigate the chance of detecting proto-planetary or debris disks in stars that induce microlensing events (lenses). The modification of the light curves shapes due to occultation and extinction by the disks as well as the additional…

Earth and Planetary Astrophysics · Physics 2015-05-13 M. Hundertmark , F. V. Hessman , S. Dreizler

We investigate the pattern of anomalies in the light curves of caustic-crossing binary microlensing events induced by spot(s) on the lensed source star. For this purpose, we perform simulations of events with various models of spots. From…

Astrophysics · Physics 2009-11-07 Heon-Young Chang , Cheongho Han

To generate the standard microlensing light curve one assumes that the relative motion of the source, the lens, and the observer is linear. In reality, the relative motion is likely to be more complicated due to accelerations of the…

Astrophysics · Physics 2009-11-07 M. C. Smith , S. Mao , B. Paczynski

Gravitational weak lensing by large scale structures is view as a tool to probe the bias relation between the mass and the light distributions. It is explained how a particular statistic can be used to deproject the 2D mass distribution…

Astrophysics · Physics 2007-05-23 L. Van Waerbeke