English
Related papers

Related papers: Extended-Source Effect and Chromaticity in Two-Poi…

200 papers

Microlensing of stars in strongly lensed galaxies can lead to temporary extreme magnification factors ($\mu\!>\!1000$), enabling their detection at high redshifts. Following the discovery of Icarus, several stars at cosmological distances…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-03 J. M. Palencia , J. M. Diego , B. J. Kavanagh , J. Martinez

The observed enhancement of the Fe K$\alpha$ line in three gravitationally lensed QSOs (MG J0414+0534, QSO 2237+0305, H1413+117) is interpreted in terms of microlensing, even when equivalent X-ray continuum amplification is not observed. In…

Observations of microlensing transit events can be used to measure the limb darkening of the lensed star. We discuss the advantages and drawbacks of several microlensing light curve inversion methods. The method of choice in this work is…

Astrophysics · Physics 2009-11-07 David Heyrovsky

The total amplification of a source inside a caustic curve of a binary lens is no less than 3. Here we show that the infimum amplification 3 is satisfied by a family of binary lenses where the source position is at the mid-point between the…

Astrophysics · Physics 2016-08-30 Sun Hong Rhie

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

Over the past decade, microlensing has developed into a powerful tool to study stellar astrophysics, especially stellar atmospheres, stellar masses, and binarity. I review this progress. Stellar atmospheres can be probed whenever the source…

Astrophysics · Physics 2016-08-30 Andrew Gould

We investigate the finite source size effect in the context of the wave optics in the gravitational lensing. The magnification of an extended source is presented in an analytic manner for the singular isothermal sphere lens model as well as…

Astrophysics · Physics 2009-11-11 Norihito Matsunaga , Kazuhiro Yamamoto

In this paper we analyze the biasing effect of point sources, either thermal Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that the…

Astrophysics · Physics 2008-11-26 Daniel Babich , Elena Pierpaoli

Quasar microlensing offers a unique opportunity to resolve tiny sources in distant active galactic nuclei and study compact object populations in lensing galaxies. We therefore searched for microlensing-induced variability of the…

The Hubble Deep Field (North) and the flanking fields are used investigate the occurrence of multiple weak lensing deflections along the line of sight in relatively deep imaging data (z_lens ~ 0.6, z_source ~ 1.2). Ray tracing simulations…

Astrophysics · Physics 2009-11-10 Tereasa G. Brainerd

One possibility for detecting low-amplitude pulsational variations is through gravitational microlensing. During a microlensing event, the temporary brightness increase leads to improvement in the signal-to-noise ratio, and thereby better…

Solar and Stellar Astrophysics · Physics 2021-09-01 Sedighe Sajadian , Richard Ignace , Hilding Neilson

The two outer triangular caustics (regions of infinite magnification) of a close binary microlens move much faster than the components of the binary themselves, and can even exceed the speed of light. When $\epsilon > 1$, where $\epsilon c$…

Astrophysics · Physics 2009-10-31 Zheng Zheng , Andrew Gould

Source blending in microlensing experiments is known to modify the Einstein time of the observed events. In this paper, we have conducted Monte-Carlo calculations, using the analytical relationships derived by Han (1999) to quantify the…

Astrophysics · Physics 2009-11-11 Yann Alibert , Gilles Chabrier , Gerard Massacrier

This paper extends the method introduced in Rivi et al. (2016b) to measure galaxy ellipticities in the visibility domain for radio weak lensing surveys. In that paper we focused on the development and testing of the method for the simple…

Instrumentation and Methods for Astrophysics · Physics 2018-04-16 Marzia Rivi , Lance Miller

In the presence of strong clustering, low-resolution surveys measure the summed contributions of groups of sources within the beam. The counts of bright intensity peaks are therefore shifted to higher flux levels compared to the counts of…

A comprehensive new approach is presented for deriving probability densities of physical properties characterizing lens or source that constitute an observed galactic microlensing event. While previously encountered problems are overcome,…

Astrophysics · Physics 2009-11-11 M. Dominik

The phenomenon of microlensing has successfully been used to detect extrasolar planets. By observing characteristic, rare deviations in the gravitational microlensing light curve one can discover that a lens is a star--planet system. In…

Earth and Planetary Astrophysics · Physics 2014-04-15 Krzysztof Rybicki , Łukasz Wyrzykowski

We use spectroscopic observations of the gravitationally lensed systems SDSS0924+0219(BC), Q1355-2257(AB), and SDSS1029+2623(BC) to analyze microlensing and dust extinction in the observed components. We detect chromatic microlensing…

Astrophysics of Galaxies · Physics 2020-02-10 K. Rojas , V. Motta , E. Mediavilla , J. JimÉnez-Vicente , E. Falco , C. Fian

We have worked out simple analytical formulae that accurately approximate the relationship between the position of the source with respect to the lens center and the amplification of the images, hence the lens cross section, for realistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Lapi , M. Negrello , J. Gonzalez-Nuevo , Z. -Y. Cai , G. De Zotti , L. Danese

Flux magnification is an interesting complement to shear-based lensing measurements, especially at high redshift where sources are harder to resolve. One measures either changes in the source density (magnification bias) or in the shape of…

Astrophysics of Galaxies · Physics 2015-12-09 Hendrik Hildebrandt