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Related papers: A Chromaticity Analysis and PSF Subtraction Techni…

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Compressed Sensing (CS) is suitable for remote acquisition of hyperspectral images for earth observation, since it could exploit the strong spatial and spectral correlations, llowing to simplify the architecture of the onboard sensors.…

Information Theory · Computer Science 2014-03-10 Simeon Kamdem Kuiteing , Giulio Coluccia , Alessandro Barducci , Mauro Barni , Enrico Magli

Several items on the diagnostics and interpretation of coronal loop observations are under debate. In this work, we analyze a well-defined loop system detected in a time-resolved observation in several spectral bands. The dataset includes…

Astrophysics · Physics 2009-11-11 Fabio Reale , Angela Ciaravella

Current and future high contrast imaging instruments aim to detect exoplanets at closer orbital separations, lower masses, and/or older ages than their predecessors, with the eventual goal of directly detecting terrestrial-mass…

Instrumentation and Methods for Astrophysics · Physics 2021-08-31 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem , Thomas D Yuzvinsky , Holger Schmidt

The next fundamental steps forward in understanding our place in the universe could be a result of advances in extreme contrast ratio (ECR) imaging and point spread function (PSF) suppression. For example, blinded by quasar light we have…

Instrumentation and Methods for Astrophysics · Physics 2016-03-09 D. Batcheldor , R. Foadi , C. Bahr , J. Jenne , Z. Ninkov , S. Bhaskaran , T. Chapman

We report laboratory results of a coronagraphic test bench to assess the intensity reduction differences between a "Gaussian" tapered focal plane coronagraphic mask and a classical hard-edged "Top Hat" function mask at Extreme Adaptive…

Astrophysics · Physics 2009-11-11 Ryeojin Park , Laird M. Close , Nick Siegler , Eric L. Nielsen , Thomas Stalcup

This paper introduces a sampling frequency offset (SFO) estimation method based on the Farrow structure, which is typically utilized for the SFO compensation and thereby enables a reduction of the implementation complexity of the SFO…

Signal Processing · Electrical Eng. & Systems 2025-09-19 Deijany Rodriguez Linares , Oksana Moryakova , Håkan Johansson

Directly observing exoplanets with coronagraphs is impeded by the presence of speckles from aberrations in the optical path, which can be mitigated in hardware with wavefront control as well as in post-processing. This work explores using…

Instrumentation and Methods for Astrophysics · Physics 2025-04-03 Yinzi Xin , Laurent Pueyo , Romain Laugier , Leonid Pogorelyuk , Ewan S. Douglas , Benjamin J. S. Pope , Kerri L. Cahoy

Chemical recycling of plastics to its constituent monomers is a promising solution to develop a sustainable circular plastic economy. An in-situ X-ray absorption spectra (XAS) characterization is an important way to understand the…

Materials Science · Physics 2024-10-02 Zhengxing Peng , Antoine Lainé , Ka Chon Ng , Mutian Hua , Brett A. Helms , Miquel B. Salmeron , Cheng Wang

The baryon acoustic oscillation (BAO) experiment requires a sufficiently dense sampling of large-scale structure tracers with spectroscopic redshift, which is observationally expensive especially at high redshifts $z\simgt 1$. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Atsushi J. Nishizawa , Masamune Oguri , Masahiro Takada

We present an analysis of the 2013 Suzaku campaign on the nearby luminous quasar PDS 456, covering a total duration of ~1 Ms and a net exposure of 455 ks. During these observations, the X-ray flux was suppressed by a factor of >10 in the…

High Energy Astrophysical Phenomena · Physics 2016-02-24 Gabriele A. Matzeu , James N. Reeves , Emanuele Nardini , Valentina Braito , Michele T Costa , Francesco Tombesi , Jason Gofford

Coronagraphs are highly sensitive to wavefront errors, with performance degrading rapidly in the presence of low-order aberrations. Correcting these aberrations at the coronagraphic focal plane is key to optimal performance. We present two…

Instrumentation and Methods for Astrophysics · Physics 2023-12-13 Michael Bottom , Samuel A. U. Walker , Ian Cunnyngham , Charlotte Guthery , Jacques-Robert Delorme

Cosmic shear has been identified as the method with the most potential to constrain dark energy. To capitalise on this potential it is necessary to measure galaxy shapes with great accuracy, which in turn requires a detailed model for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 L. M. Voigt , S. L. Bridle , A. Amara , M. Cropper , T. D. Kitching , R. Massey , J. Rhodes , T. Schrabback

The detection and characterization of extrasolar planets with SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch) is challenging and in particular relies on the ability of a coronagraph to attenuate the diffracted starlight.…

High-contrast imaging of exoplanets hinges on powerful post-processing methods to denoise the data and separate the signal of a companion from its host star, which is typically orders of magnitude brighter. Existing post-processing…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 Timothy D. Gebhard , Markus J. Bonse , Sascha P. Quanz , Bernhard Schölkopf

The ESO-Spitzer extragalactic Imaging Survey (ESIS) is the optical follow up of the Spitzer Wide-Area InfraRed Extragalactic (SWIRE) survey in the ELAIS-S1 area. This paper presents B, V, R Wide Field Imager observations of the first 1.5…

Direct exoplanet imaging via coronagraphy requires maintenance of high contrast in a dark hole for lengthy integration periods. Wavefront errors that change slowly over that time accumulate and cause systematic errors in the star's Point…

Instrumentation and Methods for Astrophysics · Physics 2019-03-08 Leonid Pogorelyuk , N. Jeremy Kasdin

Cardiac Magnetic Resonance Imaging (MRI) is time-consuming and error-prone. To ease the patient's burden and to increase the efficiency and robustness of cardiac exams, interest in methods based on continuous steady-state acquisition and…

Medical Physics · Physics 2020-10-06 Sebastian Rosenzweig , Nick Scholand , H. Christian M. Holme , Martin Uecker

The rest-frame UV/optical variability of the quasars in the Sloan Digital Sky Survey (SDSS) Stripe 82 is used to test the Corona-Heated Accretion-disk Reprocessing (CHAR) model of Sun et al. 2020. We adopt our CHAR model and the observed…

High Energy Astrophysical Phenomena · Physics 2020-10-14 Mouyuan Sun , Yongquan Xue , Hengxiao Guo , Junxian Wang , W. N. Brandt , Jonathan R. Trump , Zhicheng He , Tong Liu , Jianfeng Wu , Haikun Li

Accurately accounting for spectral structure in spectrometer data induced by instrumental chromaticity on scales relevant for detection of the 21-cm signal is among the most significant challenges in global 21-cm signal analysis. In the…

A key challenge of high contrast imaging (HCI) is to differentiate a speckle from an exoplanet signal. The sources of speckles are a combination of atmospheric residuals and aberrations in the non-common path. Those non-common path…