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We propose a direct imaging method for the detection of exoplanets based on a combined low-rank plus structured sparse model. For this task, we develop a dictionary of possible effective circular trajectories a planet can take during the…

Instrumentation and Methods for Astrophysics · Physics 2023-01-18 Simon Vary , Hazan Daglayan , Laurent Jacques , Pierre-Antoine Absil

Circumstellar disks play a key role in the understanding of stellar systems. Direct imaging of such extended structures is a challenging task. Current post-processing techniques, first tailored for exoplanets imaging, tend to produce…

Instrumentation and Methods for Astrophysics · Physics 2019-02-27 Benoît Pairet , Faustine Cantalloube , Laurent Jacques

Gravitational microlensing is one of the methods to detect exoplanets; planets outside our solar system. Here we focus on theoretical modeling of three lens systems and in particular circumbinary systems. Circumbinary systems include two…

Earth and Planetary Astrophysics · Physics 2021-09-30 Brett George , Eleni-Alexandra Kontou , Patrycja Przewoznik , Eleanor Turrell

We introduce an algorithm for a search of extremal fractal curves in large curve classes. It heavily uses SAT-solvers~ -- heuristic algorithms that find models for CNF boolean formulas. Our algorithm was implemented and applied to the…

Metric Geometry · Mathematics 2021-12-24 Yuri Malykhin , Evgeny Shchepin

Modern applications of strong gravitational lensing require the ability to use precise and varied observational data to constrain complex lens models. I discuss two sets of computational methods for lensing calculations. The first is a new…

Astrophysics · Physics 2007-05-23 Charles R. Keeton

Microlensing is a powerful tool for discovering cold exoplanets, and the The Roman Space Telescope microlensing survey will discover over 1000 such planets. Rapid, automated classification of Roman's microlensing events can be used to…

Earth and Planetary Astrophysics · Physics 2021-03-03 Somayeh Khakpash , Joshua Pepper , Matthew Penny , B. Scott Gaudi , R. A. Street

Galaxy-scale strong gravitational lensing is not only a valuable probe of the dark matter distribution of massive galaxies, but can also provide valuable cosmological constraints, either by studying the population of strong lenses or by…

Instrumentation and Methods for Astrophysics · Physics 2017-12-06 Francois Lanusse , Quanbin Ma , Nan Li , Thomas E. Collett , Chun-Liang Li , Siamak Ravanbakhsh , Rachel Mandelbaum , Barnabas Poczos

In the companion paper we began the task of systematically studying the detection of planets in wide orbits ($a > 1.5 R_E$) via microlensing surveys. In this paper we continue, focusing on repeating events. We find that, if all planetary…

Astrophysics · Physics 2009-10-31 Rosanne Di Stefano , Richard A. Scalzo

We introduce a new method of searching for and characterizing extra-solar planets. We show that by monitoring the center-of-light motion of microlensing alerts using the next generation of high precision astrometric instruments the…

Astrophysics · Physics 2009-10-31 Neda Safizadeh , Neal Dalal , Kim Griest

In this paper, we present a novel approach to the estimation of strongly varying backgrounds in astronomical images by means of small objects removal and subsequent missing pixels interpolation. The method is based on the analysis of a…

Instrumentation and Methods for Astrophysics · Physics 2016-08-10 Adam Popowicz , Bogdan Smolka

Cosmological gravitational microlensing is a useful technique for understanding the structure of the inner parts of a quasar, especially the accretion disk and the central supermassive black hole. So far, most of the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-03 Georgios Vernardos , Christopher J. Fluke

Longtime monitoring of gravitational lens systems is often done using telescopes and recording equipment with modest resolution. Still, it would be interesting to get as much information as possible from the measured lightcurves. From high…

Astrophysics · Physics 2015-06-24 A. Hirv , T. Eenmäe , T. Liimets , L. J. Liivamägi , J. Pelt

This study introduces a novel unsupervised medical image feature extraction method that employs spatial stratification techniques. An objective function based on weight is proposed to achieve the purpose of fast image recognition. The…

Image and Video Processing · Electrical Eng. & Systems 2024-06-28 Qishi Zhan , Dan Sun , Erdi Gao , Yuhan Ma , Yaxin Liang , Haowei Yang

Microlensing light curves are now being monitored with the precision required to detect small perturbations due to planetary companions of the primary lens. Microlensing is complementary to other planetary search techniques in its potential…

Astrophysics · Physics 2009-10-31 B. Scott Gaudi , Penny D. Sackett

We present a comparison between two optical cluster finding methods: a matched filter algorithm using galaxy angular coordinates and magnitudes, and a percolation algorithm using also redshift information. We test the algorithms on two mock…

Astrophysics · Physics 2009-11-10 D. Rizzo , C. Adami , S. Bardelli , A. Cappi , E. Zucca , B. Guiderdoni , G. Chincarini , A. Mazure

Among more than 200 extrasolar planet candidates discovered to date, there is no known planet orbiting around normal binary stars. In this paper, we demonstrate that microlensing is a technique that can detect such planets. Microlensing…

Astrophysics · Physics 2009-11-13 Cheongho Han

The advent of high-contrast imaging instruments combined with medium-resolution spectrographs allows spectral and temporal dimensions to be combined with spatial dimensions to detect and potentially characterize exoplanets with higher…

Earth and Planetary Astrophysics · Physics 2024-09-11 Rakesh Nath-Ranga , Olivier Absil , Valentin Christiaens , Emily O. Garvin

We present a semi-automated method to search for strong galaxy-galaxy lenses in optical imaging surveys. Our search technique constrains the shape of strongly lensed galaxies (or arcs) in a multi-parameter space, which includes the third…

Astrophysics · Physics 2008-11-07 Jeffrey M. Kubo , Ian P. Dell'Antonio

We introduce the use of the Fast Multipole Method (FMM) to speed up gravitational lensing ray tracing calculations. The method allows very fast calculation of ray deflections when a large number of deflectors, $N_*$, is involved, while…

Astrophysics of Galaxies · Physics 2022-12-21 J. Jiménez Vicente , E. Mediavilla