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An intervening galaxy acts as a gravitational lens and produces multiple images of a single source such as a remote galaxy. Galaxies have peculiar speeds in addition to the bulk motion arising due to the expansion of the universe. There is…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-23 Gihan Weerasekara , Thulsi Wickramasinghe , Chandana Jayaratne

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

I show how weak gravitational lensing can be used to image the 3-D mass distribution in the Universe. An inverse relation to the lensing equation, relating the lensing potential evaluated at each source to the full 3-D Newtonian potential,…

Astrophysics · Physics 2007-05-23 A. N. Taylor

We propose a possible measurement of the time variability of the vacuum energy using strong gravitational lensing events. As an example we take an Einstein cross lens HST 14176+5226 and demonstrate that the measurement of the velocity…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Toshifumi Futamase , Shijun Yoshida

(abridged) Some difficulties in determining the physical properties that lead to observed anomalies in microlensing light curves, such as the mass and separation of extra-solar planets orbiting the lens star, or the relative source-lens…

Astrophysics · Physics 2009-11-13 M. Dominik

We explore the distribution of mass about the expected sites of galaxy formation in a high-resolution hydrodynamical simulation of a LCDM cosmology which includes cooling, star-formation and feedback. We show that the evolution of the…

Astrophysics · Physics 2007-05-23 Martin White , Lars Hernquist , Volker Springel

We conduct gravitational microlensing experiments in a galaxy taken from a cosmological N-body simulation. Hypothetical observers measure the optical depth and event rate toward hypothetical LMCs and compare their results with model…

Astrophysics · Physics 2009-10-30 Lawrence M. Widrow , John Dubinski

As observers of the universe we are physical systems within it. If the universe is very large in space and/or time, the probability becomes significant that the data on which we base predictions is replicated at other locations in…

High Energy Physics - Theory · Physics 2015-05-18 Mark Srednicki , James Hartle

In this paper we investigate the properties of astrometric microlensing of distant radio sources (QSOs and radio galaxies) due to MACHOs, and discuss their implications for VERA (VLBI Exploration of Radio Astrometry). First we show that in…

Astrophysics · Physics 2015-06-24 Mareki Honma

Many gravitationally lensed quasars exhibit flux ratio "anomalies" that cannot be explained under the hypothesis that the lensing potential is smooth on scales smaller than one kpc. Micro-lensing by stars is a natural source of granularity…

Astrophysics · Physics 2007-05-23 Paul L. Schechter , Joachim Wambsganss

Measurements of the Hubble-Lema\^{i}tre constant ($H_0$) require us to estimate the distance and recession velocity of galaxies independently. Gravitational clustering that leads to the formation of galaxies and the large scale structure…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 Swati Gavas , J S Bagla , Nishikanta Khandai

We explore the usefulness of future gravitational microlensing surveys in the study of binary properties such as the binary fraction and the distributions of binary separation and mass ratio by using the binary sample detectable through a…

Astrophysics · Physics 2008-11-26 Cheongho Han

Galaxy lenses are frequently modeled as an elliptical mass distribution with external shear and isothermal spheres to account for secondary and line-of-sight galaxies. There is statistical evidence that some fraction of observed quads are…

Astrophysics of Galaxies · Physics 2021-04-14 Matthew R. Gomer , Liliya L. R. Williams

We present a percent-level accurate model of the line-of-sight velocity distribution of galaxies around dark matter halos as a function of projected radius and halo mass. The model is developed and tested using synthetic galaxy catalogs…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Han Aung , Daisuke Nagai , Eduardo Rozo , Brandon Wolfe , Susmita Adhikari

In this article, we have investigated the possibility to distinguish between different galactic models through the microlensing parallax studies. We show that a systematic search for parallax effects can be done using the currently running…

Astrophysics · Physics 2007-05-23 S. Rahvar , M. Moniez , R. Ansari , O. Perdereau

The luminosity variation of a stellar source due to the gravitational microlensing effect can be considered also if the light rays are defocused (instead of focused) toward the observer. In this case, we should detect a gap instead of a…

In this article we review the astrophysical application of gravitational microlensing. After introducing the history of gravitational lensing, we present the key equations and concept of microlensing. The most frequent microlensing events…

Instrumentation and Methods for Astrophysics · Physics 2016-03-21 Sohrab Rahvar

Recently, it has been shown that it is possible to reconstruct the projected mass distribution of a cluster from weak lensing provided that both the geometry of the universe and the probability distribution of galaxy redshifts are known;…

Astrophysics · Physics 2007-05-23 Marco Lombardi , Giuseppe Bertin

The event reconstruction in high energy neutrino telescopes is based on the expression of the time delay distribution of the detected photons propagating to some distance from their emission point through a uniform and scattering medium.…

Astrophysics · Physics 2007-05-23 George Japaridze , Mathieu Ribordy

In the present paper we develop an algorithm allowing to calculate line-of-sight velocity dispersions in an axisymmetric galaxy outside of the galactic plane. When constructing a self-consistent model, we take into account the galactic…

Astrophysics · Physics 2009-11-11 Elmo Tempel , Peeter Tenjes
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