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Radio interferometry is a powerful technique that allows astronomers to create high-resolution images of astronomical objects. The distribution of radio telescopes in an interferometer is a critical factor that determines the resolution and…

Instrumentation and Methods for Astrophysics · Physics 2024-09-04 Elio Quiroga Rodriguez

High-quality test mass substrates play essential roles in laser interferometric gravitational wave detectors. Inhomogeneous birefringence distribution in test mass substrates, however, can degrade the sensitivity of the detector by…

The knowledge of the exact structure of the optical system PSF enables a high-quality image reconstruction in fluorescence microscopy. Accurate PSF models account for the vector nature of light and the phase and amplitude modifications.…

We demonstrate that artificial bipolar structure can be detected using spectro-astrometry when the point spread function (PSF) of a point source suffers distortion in a relatively wide slit. Spectro-astrometry is a technique which allows us…

Astrophysics · Physics 2009-11-13 E. Brannigan , M. Takami , A. Chrysostomou , J. Bailey

The Poincar\'e sphere is a graphical representation in a three-dimensional space for the polarization of light. Similarly, an optical element with spatially varying birefringence can be represented by a surface on a four-dimensional…

Optics · Physics 2018-02-14 Anthony Vella , Miguel A. Alonso

Accurate knowledge of the telescope's point spread function (PSF) is essential for the weak gravitational lensing measurements that hold great promise for cosmological constraints. For space telescopes, the PSF may vary with time due to…

Astrophysics · Physics 2009-11-13 Zhaoming Ma , Gary Bernstein , Alan Weinstein , Michael Sholl

Planned wide-field weak lensing surveys are expected to reduce the statistical errors on the shear field to unprecedented levels. In contrast, systematic errors like those induced by the convolution with the point spread function (PSF) will…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-23 M. Gentile , F. Courbin , G. Meylan

We introduce a new algorithm for interpolating measurements of the point-spread function (PSF) using stars from many exposures. The principal components of the variation in the PSF pattern from multiple exposures are used to solve for…

Astrophysics · Physics 2007-05-23 Mike Jarvis , Bhuvnesh Jain

Orientation mapping is a widely used technique for revealing the microstructure of a polycrystalline sample. The crystalline orientation at each point in the sample is determined by analysis of the diffraction pattern, a process known as…

Mathematical Physics · Physics 2017-10-11 Peter Mahler Larsen , Søren Schmidt

The light received by source stars in microlensing events may be significantly polarized if both an efficient photon scattering mechanism is active in the source stellar atmosphere and a differential magnification is therein induced by the…

Solar and Stellar Astrophysics · Physics 2015-06-17 G. Ingrosso , F. De Paolis , A. A. Nucita , F. Strafella , S. Calchi Novati , Ph. Jetzer , G. Liuzzi , A. Zakharov

The process of identifying stars is integral toward stellar based orientation determination in spacecraft. Star identification involves matching points in an image of the sky with stars in an astronomical catalog. A unified framework for…

Data Structures and Algorithms · Computer Science 2018-08-28 Glenn Galvizo , Lipyeow Lim

A new astronomical photo-polarimeter that can measure linear polarization of point sources simultaneously in three spectral bands was designed and built in Indian Institute of Astrophysics. The polarimeter has a Calcite beam-displacement…

Instrumentation and Methods for Astrophysics · Physics 2015-06-30 A. V. Raveendran , G. Srinivasulu , S. Muneer , M. V. Mekkaden , N. Jayavel , M. R. Somashekar , K. Sagayanathan , S. Ramamoorthy , M. J. Rosario , K. Jayakumar

Based on diffraction theory and the propagation of the light, Fourier optics is a powerful tool allowing the estimation of a visible-range imaging system to transfer the spatial frequency components of an object. The analyses of the imaging…

General Physics · Physics 2018-06-05 Stephane Perrin , Paul Montgomery

Birefringence, an inherent characteristic of optically anisotropic materials, is widely utilized in various imaging applications ranging from material characterizations to clinical diagnosis. Polarized light microscopy enables…

Polarimetric interferometry is a method allowing the study of the distribution of polarized flux at diffraction-limited resolution. Its basic observable is the ratio $\mathcal{R}$ of the visibilities of the object in two orthogonal…

Instrumentation and Methods for Astrophysics · Physics 2019-02-27 Boris Safonov , Pavel Lysenko , Maria Goliguzova , Dmitry Cheryasov

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

Sensitive measurements of the linearly polarized spectra of stars can be used to deduce geometric properties of their otherwise unresolved circumstellar environments. This paper describes some of the evidence for optical pumping and…

Solar and Stellar Astrophysics · Physics 2015-03-17 J. R. Kuhn , B Geiss , D. M. Harrington

We consider a method for obtaining information on polarization of astronomical objects radiation at diffraction limited resolution - differential speckle polarimetry. As an observable we propose to use averaged cross spectrum of two…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Boris Safonov

We utilize the localization analysis method to precisely determine the light beam positions with the spatial separation beyond the optical diffraction limit. By such a direct spatial measurement, the associated optical setup is built to…

Instrumentation and Detectors · Physics 2018-10-11 Hoi Chun Chiu , Zhuohui Zeng , Luwei Zhao , Teng Zhao , Shengwang Du , Xian Chen

We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand…

Astrophysics · Physics 2011-02-11 W. H. de Vries , S. S. Olivier , S. J. Asztalos , L. J. Rosenberg , K. L. Baker