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We present a three dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies for the tell-tale distortions caused by…

Aims. We aim to detect molecules in the atmosphere of the young forming companion PDS70 b by searching for atmospheric absorption features typical of substellar objects. Methods. We obtained medium-resolution (R$\approx$5075) spectra of the…

Earth and Planetary Astrophysics · Physics 2021-09-01 G. Cugno , P. Patapis , T. Stolker , S. P. Quanz , A. Boehle , H. J. Hoeijmakers , G. -D. Marleau , P. Mollière , E. Nasedkin , I. A. G. Snellen

Hyperspectral image produces high spectral resolution at the sacrifice of spatial resolution. Without reducing the spectral resolution, improving the resolution in the spatial domain is a very challenging problem. Motivated by the discovery…

Image and Video Processing · Electrical Eng. & Systems 2022-12-07 Qiang Li , Yuan Yuan , Xiuping Jia , Qi Wang

This article begins with the discussions on the formation of speckles in the case of non-coherent quasi monochromatic source and of ways to detect them. Prior to this, a brief introduction on the behavior of the atmosphere and its effect on…

Astrophysics · Physics 2007-05-23 Swapan K. Saha

Adaptive optics (AO) have been used to correct wavefronts to achieve diffraction limited point spread functions in a broad range of optical applications, prominently ground-based astronomical telescopes operating in near infra-red. While…

Instrumentation and Methods for Astrophysics · Physics 2018-10-03 Alexandre J. T. S. Mello , Antonin H. Bouchez , Andrew Szentgyorgyi , Marcos A. van Dam , Henrique Lupinari

Targeting dynamic spatially-extended phenomena in the upper solar atmosphere, a new instrument concept has been developed and tested at the Dunn Solar Telescope in New Mexico, USA, that provides wide-field, rapid-scanning, high-resolution…

Instrumentation and Methods for Astrophysics · Physics 2018-09-17 Thomas A. Schad , Haosheng Lin

The purpose of this paper is to introduce the main scientific results made by the one-meter New Vacuum Solar Telescope (NVST), which was put into commission on 2010. NVST is one of the large aperture solar telescopes in the world, located…

Solar and Stellar Astrophysics · Physics 2019-10-22 Xiaoli Yan , Zhong Liu , Jun Zhang , Zhi Xu

We developed a scan mirror mechanism (SMM) that enable a slit-based spectrometer or spectropolarimeter to precisely and quickly map an astronomical object. The SMM, designed to be installed in the optical path preceding the entrance slit,…

To precisely measure and evaluate X-ray generation and evolution in a hohlraum during an implosion process, we present a two-dimensional (2D) time- and space-resolved diagnostic method by combining a compressed ultrafast photography (CUP)…

Instrumentation and Detectors · Physics 2021-10-13 Shijian Li , Qiangqiang Wang , Xuri Yao , Zhurong Cao , Jie Liu , Qing Zhao

Two-dimensional, resonant scanners have been utilized in a large variety of imaging modules due to their compact form, low power consumption, large angular range, and high speed. However, resonant scanners have problems with non-optimal and…

Image and Video Processing · Electrical Eng. & Systems 2023-05-05 Zhanghao Sun , Ronald Quan , Olav Solgaard

Multispectral Sentinel-2 images are a valuable source of Earth observation data, however spatial resolution of their spectral bands limited to 10 m, 20 m, and 60 m ground sampling distance remains insufficient in many cases. This problem…

Computer Vision and Pattern Recognition · Computer Science 2023-11-06 Tomasz Tarasiewicz , Jakub Nalepa , Reuben A. Farrugia , Gianluca Valentino , Mang Chen , Johann A. Briffa , Michal Kawulok

The Solar Orbiter mission, with an orbit outside the Sun Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time, different…

Solar and Stellar Astrophysics · Physics 2021-11-24 O. Podladchikova , L. Harra , K. Barczynski , C. H. Mandrini , F. Auchere , D. Berghmans , E. Buchlin , L. Dolla , M. Mierla , S. Parenti , L. Rodriguez

In recent years, there has been a proliferation of wide-field sky surveys to search for a variety of transient objects. Using relatively short focal lengths, the optics of these systems produce undersampled stellar images often marred by a…

Astrophysics · Physics 2009-11-13 Fang Yuan , Carl W. Akerlof

High resolution (~1 arcminute) astronomical imaging at low frequency (below 150 MHz) has only recently become practical with the development of new calibration algorithms for removing ionospheric distortions. In addition to opening a new…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 A. S. Cohen , H. J. A. Röttgering

Transmission spectroscopy is currently the technique best suited to study a wide range of planetary atmospheres, leveraging the filtering of a star's light by a planet's atmosphere rather than its own emission. However, as both a planet and…

Earth and Planetary Astrophysics · Physics 2024-01-08 David Berardo , Julien de Wit , Benjamin V. Rackham

The spatial-temporal evolution of coronal plasma parameters of the solar outer atmosphere at global scales, derived from solar full-disk imaging spectroscopic observation in the extreme-ultraviolet band, is critical for understanding and…

Solar and Stellar Astrophysics · Physics 2024-10-23 Yufei Feng , Xianyong Bai , Sifan Guo , Hui Tian , Lami Chan , Yuanyong Deng , Qi Yang , Wei Duan , Xiaoming Zhu , Xiao Yang , Zhiwei Feng , Zhiyong Zhang

4D-STEM, in which the 2D diffraction plane is captured for each 2D scan position in the scanning transmission electron microscope (STEM) using a pixelated detector, is complementing and increasingly replacing existing imaging approaches.…

Instrumentation and Detectors · Physics 2022-07-27 Colum M. O'Leary , Benedikt Haas , Christoph T. Koch , Peter D. Nellist , Lewys Jones

We carry out non-rotating high-resolution calculations of the solar global convection, which resolve convective scales of less than 10 Mm. To cope with the low Mach number conditions in the lower convection zone, we use the reduced speed of…

Solar and Stellar Astrophysics · Physics 2015-06-18 H. Hotta , M. Rempel , T. Yokoyama

In recent years, dedicated extreme-precision radial velocity (EPRV) spectrographs have produced vast quantities of high-resolution, high-signal-to-noise time-series spectra for bright stars. These data contain valuable information for the…

Instrumentation and Methods for Astrophysics · Physics 2019-10-09 Megan Bedell , David W. Hogg , Daniel Foreman-Mackey , Benjamin T. Montet , Rodrigo Luger

Measurements of low-order p modes and gravity modes are perturbed by the solar convective background. Such perturbation increases below 2mHz for intensity measurements and 1mHz for velocity measurements. While the low-degree modes have…

Astrophysics · Physics 2008-10-10 R. A. Garcia , S. Mathur , I. Gonzalez Hernandez , A. Jimenez
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