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Related papers: Microlensing of an Elliptical Source by a Point Ma…

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The breaks and truncations in the luminosity profile of face-on spiral galaxies offer valuable insights in their formation history. The traditional method of deriving the surface photometry profile for face-on galaxies is to use elliptical…

Astrophysics of Galaxies · Physics 2016-11-15 S. P. C. Peters , P. C. van der Kruit , R. S. de Jong

A fast and practical method is described for calculating the microlensed flux variance of an arbitrary source by uncorrelated stars. The required inputs are the mean convergence and shear due to the smoothed potential of the lensing galaxy,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jeremy Goodman , Ai-Lei Sun

The aim of this paper is to study the astrometric trajectory of microlensing events with an extended lens and/or source. We consider not only a dark lens but also a luminous lens as well. We find that the discontinuous finite-lens…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 C. -H. Lee , S. Seitz , A. Riffeser , R. Bender

We generalize to elliptical models the argument of Kuijken (1997), which connects the microlensing optical depth towards the Galactic bulge to the Galactic rotation curve. When applied to the latest value from the MACHO collaboration for…

Astrophysics · Physics 2009-10-31 James Binney , Nicolai Bissantz , Ortwin Gerhard

At present, microlensing light curves from different telescopes and filters are photometrically aligned by fitting them to a common model. We present a second method based on photometry of common field stars. If two spectral responses are…

Earth and Planetary Astrophysics · Physics 2014-11-20 Andrew Gould , Subo Dong , David P. Bennett , Ian A. Bond , Andrzej Udalski , Szymon Kozlowski

We describe the methodology and compute the illumination of geometrically thin accretion disks around black holes of arbitrary spin parameter $a$ exposed to the radiation of a point-like, isotropic source at arbitrary height above the disk…

Astrophysics · Physics 2019-08-19 Keigo Fukumura , Demosthenes Kazanas

We propose a method that can determine the ellipticities of source stars of microlensing events produced by binary lenses. The method is based on the fact that the products of the caustic-crossing timescale, $\Delta t$, and the cosine of…

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

We report on a program of spectroscopic observations of gravitationally-lensed QSOs with multiple images. We seek to establish whether microlensing is occurring in each QSO image using only single-epoch observations. We calculate flux…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 V. Motta , E. Mediavilla , E. Falco , J. A. Munoz

The statistics of gravitationally lensed arcs, which can be used for a variety of cosmological tests, are sensitive to the intrinsic shapes of the source galaxies. I present an analytic formalism that makes it simple to include elliptical…

Astrophysics · Physics 2009-11-06 Charles R. Keeton

Most research on astrophysical lensing has been conducted using the geometric optics framework, where there exists a clear concept of lensing images. However, wave optics effects can be important for coherent sources, e.g. pulsars, fast…

Instrumentation and Methods for Astrophysics · Physics 2024-10-29 Xun Shi

Source extension is a reformulation of inverse problems in wave propagation, that at least in some cases leads to computationally tractable iterative solution methods. The core subproblem in all source extension methods is the solution of a…

Numerical Analysis · Mathematics 2022-04-01 William W. Symes

Analysing extended emission in photometric observations of star-forming regions requires maps free from compact foreground, embedded, and background sources, which can interfere with various techniques used to characterise the interstellar…

Instrumentation and Methods for Astrophysics · Physics 2025-04-02 M. Madarász , G. Marton , I. Gezer , S. Lehner , J. Roquette , M. Audard , D. Hernandez , O. Dionatos

The current weak lensing measurements of the large scale structure are mostly related to statistical study of background galaxy ellipticities. We consider a possibility to extend lensing studies with intrinsically unresolved sources and…

Astrophysics · Physics 2008-11-26 Asantha Cooray

We demonstrate the integration of Nd3+ doped Barium-Titanium-Silicate microsphere lasers with a Silicon Nitride photonic platform. Devices with two different geometrical configurations for extracting the laser light to buried waveguides…

We investigate the extended source size effects on gravitational lensing in which a lens consists of a smooth potential and small mass clumps (``substructure lensing''). We first consider a lens model that consists of a clump modeled as a…

Astrophysics · Physics 2009-11-10 Kaiki Taro Inoue , Masashi Chiba

We study the colour changes induced by blending in a wormhole-like microlensing scenario with extended sources. The results are compared with those obtained for limb darkening. We assess the possibility of an actual detection of the colour…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Diego F. Torres , Ernesto F. Eiroa , Gustavo E. Romero

Gravitational lensing is the phenomenon arising when light rays are deflected by the mass between the source and the observer. Largely magnified and highly distorted images of background galaxies are formed by these angular deflections if…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Atınç Çağan Şengül

We present a new method to derive reliable photometry of extended spherically symmetric sources from {\it HST} images (WFPC2, ACS/WFC and NICMOS/NIC2 cameras), extending existing studies of point sources and marginally resolved sources. We…

Astrophysics · Physics 2012-01-30 P. Anders , M. Gieles , R. de Grijs

We demonstrate an efficient method to compute the strong-gravitational-lensing deflection angle and magnification for any elliptical surface-density profile. This method solves a numerical hurdle in lens modelling that has lacked a general…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-10 Anowar J. Shajib

The strong galaxy-galaxy lensing produces highly magnified and distorted images of background galaxies in the form of arcs and Einstein rings. Statistically, these effects are quantified, for example, in the number counts of highly luminous…

Astrophysics of Galaxies · Physics 2019-03-08 Vanessa P. de Freitas , Martin Makler , Habib S. Dúmet-Montoya