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Related papers: Microlensing under Shear

200 papers

A detailed analysis is presented of gravitational microlensing by intervening compact objects of the black hole shadows imaged by the Event Horizon Telescope (EHT). We show how the center, size, and shape of the shadow depend on the…

Astrophysics of Galaxies · Physics 2024-05-14 Himanshu Verma , Joseph Silk

The expansion of the universe causes spacetime curvature, distinguishing between distances measured along and transverse to the line of sight. The ratio of these distances, e.g. the cosmic shear distortion of a sphere defined by…

Astrophysics · Physics 2009-11-07 Eric V. Linder

The tilt, rotation, or offset of each CCD with respect to the focal plane, as well as the distortion of the focal plane itself, cause shape distortions to the observed objects, an effect typically known as field distortion (FD). We point…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Jun Zhang , Fuyu Dong , Hekun Li , Xiangchong Li , Yingke Li , Dezi Liu , Wentao Luo , Liping Fu , Guoliang Li , Zuhui Fan

It is now routine to measure the weak gravitational lensing shear signal from the mean ellipticity of distant galaxies. However, conversion between ellipticity and shear assumes local linearity of the lensing potential (ie that the spatial…

Astrophysics · Physics 2010-11-11 Richard Massey , David M. Goldberg

Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source-scaling…

Astrophysics · Physics 2008-11-26 Jun Zhang , Lam Hui , Albert Stebbins

Astrometric microlensing will offer in the next future a new channel for investigating the nature of both lenses and sources involved in a gravitational microlensing event. The effect, corresponding to the shift of the position of the…

Solar and Stellar Astrophysics · Physics 2017-05-10 A. A. Nucita , F. De Paolis , G. Ingrosso , M. Giordano , L. Manni

The current modelling of single microlensing light curves neglects the possibility that only a fraction of the light is due to the lensed star, the remaining being due to a close, unresolved blend, which may be related or unrelated to the…

Astrophysics · Physics 2009-10-30 Przemyslaw Wozniak , Bohdan Paczynski

The passage of stars through the beam of a lensed quasar can induce violent fluctuations in its apparent brightness. The fluctuations observed in the Huchra lens, (2237+0305), are taken to be the first evidence of this ``microlensing''…

Astrophysics · Physics 2015-06-24 G. F. Lewis , M. J. Irwin

As gravitational lensing measurements become increasingly precise, it becomes necessary to include ever higher order effects in the theoretical calculations. Here we show how the difference between the shear and the reduced shear manifest…

Astrophysics · Physics 2008-11-26 Martin White

Cosmic shear has been identified as the method with the most potential to constrain dark energy. To capitalise on this potential it is necessary to measure galaxy shapes with great accuracy, which in turn requires a detailed model for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 L. M. Voigt , S. L. Bridle , A. Amara , M. Cropper , T. D. Kitching , R. Massey , J. Rhodes , T. Schrabback

We introduce a new method for constraining the redshift distribution of a set of galaxies, using weak gravitational lensing shear. Instead of using observed shears and redshifts to constrain cosmological parameters, we ask how well the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 D. Wittman , W. A. Dawson

Measurement of the gravitational distortion of images of distant galaxies is rapidly becoming established as a powerful probe of the dark mass distribution in clusters of galaxies. With the advent of large mosaics of CCD's these methods…

Astrophysics · Physics 2007-05-23 Nick Kaiser , Gordon Squires , Greg Fahlman , David Woods , Tom Broadhurst

Here, we study the microlensing of radially pulsating stars. Discerning and characterizing the properties of distant, faint pulsating stars is achievable through high-cadence microlensing observations. Combining stellar variability period…

Solar and Stellar Astrophysics · Physics 2020-04-22 Sedighe Sajadian , Richard Ignace

We propose and discuss a new experimental approach to measure the centroid shift induced by gravitational microlensing in the images of lensed quasars (astrometric microlensing). Our strategy is based on taking the photocenter of a region…

Astrophysics of Galaxies · Physics 2024-06-18 R. Forés-Toribio , E. Mediavilla , J. A. Muñoz , J. Jiménez-Vicente , C. Fian , C. del Burgo

In future high-cadence microlensing surveys, planets can be detected through a new channel of an independent event produced by the planet itself. The two populations of planets to be detected through this channel are wide-separation planets…

Earth and Planetary Astrophysics · Physics 2009-07-22 Cheongho Han

The microlensing monitoring programs have studied large numbers of standard light curves which seem to be due to lensing by a dark point mass. Theory predicts that many microlensing events should display significant deviations from the…

Astrophysics · Physics 2009-10-30 Rosanne Di Stefano , Rosalba Perna

We study a general elliptical potential of the form $\psi(x^2+y^2/q^2)~ (0<q\le 1)$ plus an additional shear (with an arbitrary direction) as models for the observed quadruple lenses. It is shown that a minimum additional shear is needed…

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

As the volume and quality of modern galaxy surveys increase, so does the difficulty of measuring the cosmological signal imprinted in galaxy shapes. Weak gravitational lensing sourced by the most massive structures in the Universe generates…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-04 Benjamin Remy , Francois Lanusse , Jean-Luc Starck

For cosmic shear to become an accurate cosmological probe, systematic errors in the shear measurement method must be unambiguously identified and corrected for. Previous work of this series has demonstrated that cosmic shears can be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Jun Zhang , Wentao Luo , Sebastien Foucaud