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Related papers: Speckle Statistics in Adaptively Corrected Images

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Intensity mapping is a promising technique for surveying the large scale structure of our Universe from $z=0$ to $z \sim 150$, using the brightness temperature field of spectral lines to directly observe previously unexplored portions of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Adrian Liu , Yunfan Zhang , Aaron R. Parsons

With the aim of building a data-set of spectral properties of well studied early-type galaxies showing emission lines, we present intermediate resolution spectra of 50 galaxies in the nearby Universe. The sample, which covers several of the…

Astrophysics · Physics 2009-11-10 R. Rampazzo , F. Annibali , A. Bressan , M. Longhetti , F. Padoan , W. W. Zeilinger

In this paper, we present a mathematical model and analysis for a new experimental method [Bureau and al., arXiv:2409.13901, 2024] for effective sound velocity estimation in medical ultrasound imaging. We perform a detailed analysis of the…

Analysis of PDEs · Mathematics 2025-05-13 Josselin Garnier , Laure Giovangigli , Quentin Goepfert , Pierre Millien

The phenomenon of random intensity patterns, for waves propagating in the presence of disorder, is well known in optics and in mesoscopic physics. We study this phenomenon for cold atomic gases expanding, by a diffusion process, in a weak…

Disordered Systems and Neural Networks · Physics 2009-11-13 P. Henseler , B. Shapiro

Background: Spatio-temporal receptive fields (STRF) of visual neurons are often estimated using spike-triggered averaging of binary pseudo-random stimulus sequences. The stimuli are visual displays that contain black and white pixels that…

Quantitative Methods · Quantitative Biology 2024-08-16 Murat Okatan

This paper presents a new approach for filter design based on stochastic distances and tests between distributions. A window is defined around each pixel, overlapping samples are compared and only those which pass a goodness-of-fit test are…

Information Theory · Computer Science 2013-08-30 Leonardo Torres , Tamer Cavalcante , Alejandro C. Frery

Laser speckle, the granular intensity pattern arising from random optical interference, provides a high-dimensional encoding of spectral information that can be exploited for precision metrology. Speckle-based spectrometers have advanced…

Spectral characterization of sub-stellar companions is essential to understand their composition and formation processes. However, the large contrast ratio of the brightness of each object to that of its parent star limits our ability to…

Earth and Planetary Astrophysics · Physics 2015-06-04 Arthur Vigan , Mickaël Bonnefoy , Gaël Chauvin , Claire Moutou , Guillaume Montagnier

We develop a straightforward and quantitative two-step method for spectroscopically classifying galaxies from the low signal-to-noise (S/N) optical spectra typical of galaxy redshift surveys. First, using \chi^2-fitting of characteristic…

Astrophysics · Physics 2009-10-28 Dennis Zaritsky , Ann I. Zabludoff , Jeffrey A. Willick

Intensity squeezing, i.e., photon number fluctuations below the shot noise limit, is a fundamental aspect of quantum optics and has wide applications in quantum metrology. It was predicted in 1979 that the intensity squeezing could be…

In a disordered medium with Kerr-type nonlinearity, the transmitted speckle pattern was predicted to become unstable, as a result of the positive feedback between the intensity fluctuations and the nonlinear dependence of the local…

Disordered Systems and Neural Networks · Physics 2010-04-26 Umberto Bertolozzo , Stefania Residori , Patrick Sebbah

We present an algorithm to search for the faint spectrum of a second star mixed with the spectrum of a brighter star in high resolution spectra. We model optical stellar spectra as the sum of two input spectra drawn from a vast library of…

Solar and Stellar Astrophysics · Physics 2014-12-18 Rea Kolbl , Geoffrey W. Marcy , Howard Isaacson , Andrew W. Howard

Microlensing is a powerful tool for studying stellar atmospheres because as the source crosses regions of formally infinite magnification (caustics) the surfaceof the star is resolved, thereby allowing one to measure the radial intensity…

Astrophysics · Physics 2009-10-30 B. Scott Gaudi , Andrew Gould

The major source of noise in high-contrast imaging is the presence of slowly evolving speckles that do not average with time. The temporal stability of the point-spread-function (PSF) is therefore critical to reach a high contrast with…

Instrumentation and Methods for Astrophysics · Physics 2018-07-03 J. Milli , T. Banas , D. Mouill , D. Mawet , J. H. Girard , A. Vigan , A. Boccaletti , M. Kasper , Z. Wahhaj , A. -M. Lagrange , J. -L. Beuzit , T. Fusco , J. -F. Sauvage , R. Galicher

In high-contrast space-based coronagraphs, one of the main limiting factors for imaging the dimmest exoplanets is the time varying nature of the residual starlight (speckles). Modern methods try to differentiate between the intensities of…

Instrumentation and Methods for Astrophysics · Physics 2019-09-04 Leonid Pogorelyuk , N. Jeremy Kasdin , Clarence W. Rowley

[Abridged] We investigate the frequency of the various spectral types as a function both of the clusters' properties and of the galaxies' characteristics. In this way, using the same classification criteria adopted for higher redshift…

A main science goal for the Large Synoptic Survey Telescope (LSST) is to measure the cosmic shear signal from weak lensing to extreme accuracy. One difficulty, however, is that with the short exposure time ($\simeq$15 seconds) proposed, the…

High-contrast imaging instruments are now being equipped with integral field spectrographs (IFS) to facilitate the detection and characterization of faint substellar companions. Algorithms currently envisioned to handle IFS data, such as…

Fitting spectral distributions of total fluxes or image intensities are two standard methods for estimating the masses of starless cores and protostellar envelopes. These mass estimates, which are the main source and basis of our knowledge…

Instrumentation and Methods for Astrophysics · Physics 2016-09-28 Alexander Men'shchikov

Weak lensing by large-scale mass inhomogeneities in the Universe induces correlations in the observed ellipticities of distant sources. We first review the harmonic analysis and statistics required of these correlations and discuss…

Astrophysics · Physics 2009-10-30 Marc Kamionkowski , Arif Babul , Catherine M. Cress , Alexandre Refregier