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We have developed a new technique called Direct Shear Mapping (DSM) to measure gravitational lensing shear directly from observations of a single background source. The technique assumes the velocity map of an un-lensed, stably-rotating…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-26 Catherine O. de Burgh-Day , Edward N. Taylor , Rachel L. Webster , Andrew M. Hopkins

In this paper a new fractal image compression algorithm is proposed in which the time of encoding process is considerably reduced. The algorithm exploits a domain pool reduction approach, along with using innovative predefined values for…

Computer Vision and Pattern Recognition · Computer Science 2015-01-20 H. Miar Naimi , M. Salarian

The growing rate of increase in the number of the discovered extra-solar planets which has consequently raised the enthusiasm to explore the universe in hope of finding earth-like planets has resulted in the wide use of Gravitational…

Earth and Planetary Astrophysics · Physics 2009-11-24 Karan Molaverdikhani , Maryam Tabeshian

We infer gravitational lensing shear and convergence fields from galaxy ellipticity catalogs under a spatial process prior for the lensing potential. We demonstrate the performance of our algorithm with simulated Gaussian-distributed…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Michael D. Schneider , Karen Y. Ng , William A. Dawson , Philip J. Marshall , Joshua Meyers , Deborah J. Bard

To maximize the number of planet detections by increasing efficiency, current microlensing follow-up observation experiments are focusing on high-magnification events to search for planet-induced perturbations near the peak of lensing light…

Astrophysics · Physics 2009-11-10 Cheongho Han

Like light, gravitational waves can be gravitationally lensed by massive astrophysical objects. Strong gravitational lensing by galaxies and galaxy clusters is anticipated to become observable in the coming years. This phenomenon will…

General Relativity and Quantum Cosmology · Physics 2025-06-03 Leo C. Y. Ng , Justin Janquart , Hemantakumar Phurailatpam , Harsh Narola , Jason S. C. Poon , Chris Van Den Broeck , Otto A. Hannuksela

Single-photon Lidar (SPL) offers unprecedented sensitivity and time resolution, which enables Satellite Laser Ranging (SLR) systems to identify space debris from distances spanning thousands of kilometers. However, existing SPL systems face…

Data Analysis, Statistics and Probability · Physics 2024-01-10 Xialin Liu , Jia Qiang , Genghua Huang , Liang Zhang , Zheng Zhao , Rong Shu

We propose a new parametrization of the impact parameter u0 and impact angle {\alpha} for microlensing systems composed by an Earth-like Exoplanet around a Solar mass Star at 1 AU. We present the caustic topology of such system, as well as…

Earth and Planetary Astrophysics · Physics 2018-10-17 L. de Almeida , J. -D. do Nascimento

Of all planet-finding techniques, microlensing is potentially the most sensitive to Earth-mass planets. However, microlensing lightcurves generically yield only the planet-star mass ratio: the mass itself is uncertain to a factor of a few.…

Astrophysics · Physics 2009-11-07 Andrew Gould , B. Scott Gaudi , Cheongho Han

We present DOHA, a new algorithm for cotrending photometric light curves obtained by transiting exoplanet surveys. The algorithm employs a novel approach to the traditional "differential photometry" technique, by selecting the most suitable…

Earth and Planetary Astrophysics · Physics 2016-11-24 D. Mislis , S. Pyrzas , K. A. Alsubai , Z. I. Tsvetanov , N. P. E. Vilchez

We present a new implementation of the commonly used Box-fitting Least Squares (BLS) algorithm, for the detection of transiting exoplanets in photometric data. Unlike BLS, our new implementation - Sparse BLS (SBLS), does not use binning of…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Aviad Panahi , Shay Zucker

We present the results of a new search for galaxy-scale strong lensing systems in CFHTLS Wide. Our lens-finding technique involves a preselection of potential lens galaxies, applying simple cuts in size and magnitude. We then perform a…

Astrophysics of Galaxies · Physics 2016-08-03 D. Paraficz , F. Courbin , A. Tramacere , R. Joseph , R. B. Metcalf , J. -P. Kneib , P. Dubath , D. Droz , F. Filleul , D. Ringeisen , C. Schäfer

When designing multispectral imaging systems for classifying different spectra it is necessary to choose a small number of filters from a set with several hundred different ones. Tackling this problem by full search leads to a tremendous…

Image and Video Processing · Electrical Eng. & Systems 2023-01-19 Frank Sippel , Jürgen Seiler , André Kaup

Strong gravitational lensing is a powerful tool for investigating dark matter and dark energy properties. With the advent of large-scale sky surveys, we can discover strong lensing systems on an unprecedented scale, which requires efficient…

Robust modelling of strong lensing systems is fundamental to exploit the information they contain about the distribution of matter in galaxies and clusters. In this work, we present Lensed, a new code which performs forward parametric…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-15 Nicolas Tessore , Fabio Bellagamba , R. Benton Metcalf

Direct imaging of exoplanets requires to separate the background noise from the exoplanet signals. Statistical methods have been recently proposed to avoid subtracting any signal of interest as opposed to initial self-subtracting methods…

Earth and Planetary Astrophysics · Physics 2024-12-02 Hadrien Cambazard , Nicolas Catusse , A. Chomez , A. -M. Lagrange

We propose a novel microlensing event search method that differs from either the traditional time domain method, astrometric microlensing, or the parallax microlensing method. Our method assumes that stars with nearly identical "genes" -…

Astrophysics of Galaxies · Physics 2024-11-05 Qi Guo , Leyao Wei , Wentao Luo , Shurui Lin , Qinxun Li , YiFu Cai , Di He , Qingqing Wang , Ruoxi Yang

Galaxy-scale strong gravitational lenses are valuable objects for a variety of astrophysical and cosmological applications. Strong lensing galaxies are rare, so efficient search methods, such as convolutional neural networks, are often used…

Astrophysics of Galaxies · Physics 2025-02-17 Yuichiro Ishida , Kenneth C. Wong , Anton T. Jaelani , Anupreeta More

Most current high contrast imaging point spread function (PSF) subtraction algorithms use some form of a least-squares noise minimization to find exoplanets that are, before post-processing, often hidden below the instrumental speckle…

Instrumentation and Methods for Astrophysics · Physics 2016-09-29 Benjamin L. Gerard , Christian Marois

(abridged) Aims: RXS J113155.4-123155 (z=0.66) is a quadruply imaged lensed quasar with a resolved Einstein Ring. The goal of this paper is to provide a full characterization of this system, and more particularly accurate astrometry and…