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A Bayesian statistical formalism is developed to quantify the level at which the mass function slope (alpha) and the projected cumulative mass fraction (f) of (CDM) substructure in strong gravitational-lens galaxies, with arcs or Einstein…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Vegetti , L. V. E. Koopmans

Microlensing observations of the Q0957+561 A,B have consistently shown evidence for structure in the quasar that has not been evident in available microlensing models, where the luminous source has been consistently modeled as a single…

Astrophysics · Physics 2009-11-07 Rudolph Schild , Viktor Vakulik

We argue that gravitational microlensing is a feasible technique for measuring the mass function of brown dwarf stars in distant galaxies. Microlensing surveys of the bulge of M31, and of M87 in the Virgo cluster, may provide enough events…

Astrophysics · Physics 2009-10-31 E. A. Baltz , J. Silk

We introduce a new scheme to study the nature of the central engine in a lensed QSO. The compact emission regions could have different sizes in different optical wavelengths, and our framework permits to obtain the source size ratios when a…

Astrophysics · Physics 2009-11-10 L. J. Goicoechea , V. Shalyapin , J. Gonzalez-Cadelo , A. Oscoz

Lensing flux-ratio anomalies are most likely caused by gravitational lensing by small-scale dark matter structures. These anomalies offer the prospect of testing a fundamental prediction of the cold dark matter (CDM) cosmological model: the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-20 D. D. Xu , Dominique Sluse , Liang Gao , Jie Wang , Carlos Frenk , Shude Mao , Peter Schneider

When a gravitationally lensed source crosses a caustic, a pair of images is created or destroyed. We calculate the mean number of such pairs of micro-images $<n>$ for a given macro-image of a gravitationally lensed point source, due to…

Astrophysics · Physics 2016-08-30 Jonathan Granot , Paul L. Schechter , Joachim Wambsganss

Each strongly lensed image of a quasar behind a lensing galaxy (or galaxy cluster) is composed of a swarm of micro-images. This is a result of microlensing due to stellar-scale substructure in the lens. The presence of microlenses forms a…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-05 Ashish Kumar Meena , Prasenjit Saha

The micro-arcsecond scale structure of the seemingly point-like images in lensed quasars, though unobservable, is nevertheless much studied theoretically, because it affects the observable (or macro) brightness, and through that provides…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Prasenjit Saha , Liliya L. R. Williams

In a line caustic crossing microlensing event, the caustic line moving across the surface of the source star provides a direct method to measure the integrated luminosity profile of the star. Combined with the enormous brightening at the…

Astrophysics · Physics 2007-05-23 Sun Hong Rhie , David P. Bennett

We investigate the statistics of flux anomalies in gravitationally lensed QSOs as a function of dark matter halo properties such as substructure content and halo ellipticity. We do this by creating a very large number of simulated lenses…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 R. Benton Metcalf , Adam Amara

The flux-ratio anomalies observed in multiply-lensed quasar images are most plausibly explained as the result of perturbing structures superposed on the underlying smooth matter distribution of the primary lens. The cold dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 D. D. Xu , Shude Mao , Andrew Cooper , Liang Gao , Carlos Frenk , Raul Angulo , John Helly

The analysis of the high magnification events in the A and C components of the quadruple gravitational lens QSO2237+0305 observed by OGLE and GLITP collaborations in V band was carried out. The significant light amplifications of the…

Astrophysics · Physics 2007-05-23 Ekaterina Koptelova , Elena Shimanovskaya

(Abridged) In this paper we refine the theory of microlensing for a planar distribution of point masses. We derive the macroimage magnification distribution P(A) at high magnification (A-1 >> tau^2) for a low optical depth (tau << 1) lens…

Astrophysics · Physics 2009-10-28 Lev Kofman , Nick Kaiser , Man Hoi Lee , Arif Babul

We measure the average deflection of cosmic microwave background photons by quasars at $\langle z \rangle =1.7$. Our sample is selected from the Sloan Digital Sky Survey to cover the redshift range $0.9\leq z\leq2.2$ with absolute i-band…

Astrophysics of Galaxies · Physics 2019-04-03 J. E. Geach , J. A. Peacock , A. D. Myers , R. C. Hickox , M. C. Burchard , M. L. Jones

We use the microlensing variability observed for nine gravitationally lensed quasars to show that the accretion disk size at 2500 Angstroms is related to the black hole mass by log(R_2500/cm) = (15.6+-0.2) + (0.54+-0.28)log(M_BH/10^9M_sun).…

Astrophysics · Physics 2015-05-13 Christopher W. Morgan , C. S. Kochanek , Nicholas D. Morgan , Emilio E. Falco

Weak gravitational lensing allows one to reconstruct the spatial distribution of the projected mass density across the sky. These "mass maps" provide a powerful tool for studying cosmology as they probe both luminous and dark matter. In…

We present the main results of the first long-term spectrophotometric monitoring of the ``Einstein cross'' Q2237+0305 and of the single-epoch spectra of the lensed quasar J1131-1231. From October 2004 to December 2006, we find that two…

Astrophysics · Physics 2009-04-14 D. Sluse , A. Eigenbrod , F. Courbin , D. Hutsemékers , J. -F. Claeskens , G. Meylan , E. Agol , J. Surdej

Using infrared spectra of the z = 1.693 quadruply lensed quasar HE0435-1223 acquired in 2009 with the spectrograph SINFONI at the ESO Very Large Telescope, we have detected a clear microlensing effect in images A and D. While microlensing…

Astrophysics of Galaxies · Physics 2014-05-28 L. Braibant , D. Hutsemékers , D. Sluse , T. Anguita , C. J. García-Vergara

We use the microlensing variability observed for eleven gravitationally lensed quasars to show that the accretion disk size at a rest-frame wavelength of 2500 Angstroms is related to the black hole mass by log(R_{2500}/cm)=(15.78\pm0.12) +…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Christopher W. Morgan , C. S. Kochanek , Nicholas D . Morgan , Emilio E. Falco