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Stray light in X-ray telescopes is a well-known issue. Unlike rays focused via a double reflection by usual grazing-incidence geometries such as the Wolter-I, stray rays coming from off-axis sources are reflected only once by either the…

Instrumentation and Methods for Astrophysics · Physics 2016-10-03 Daniele Spiga

Astronomical imaging with micro-arcsecond ($\mu$as) angular resolution could enable breakthrough scientific discoveries. Previously-proposed $\mu$as X-ray imager designs have been interferometers with limited effective collecting area. Here…

Instrumentation and Methods for Astrophysics · Physics 2020-06-24 Brandon D. Chalifoux , Ralf K. Heilmann , Herman L. Marshall , Mark L. Schattenburg

Observations of interstellar clouds that cast shadows in the soft X-ray background can be used to separate the background Galactic halo emission from the local emission due to solar wind charge exchange (SWCX) and/or the Local Bubble (LB).…

Astrophysics of Galaxies · Physics 2015-06-23 David B. Henley , Robin L. Shelton , Renata S. Cumbee , Phillip C. Stancil

We analyse the first measurements from precision weak lensing (PWL): a new methodology for measuring individual galaxy-galaxy weak lensing through velocity information. Our goal is to understand the observed shear distribution from PWL,…

Astrophysics of Galaxies · Physics 2021-02-24 Pol Gurri , Edward N. Taylor , Christopher J. Fluke

Reflected or scattered light produce artefacts in astronomical observations that can negatively impact the scientific study. Hence, automated detection of these artefacts is highly beneficial, especially with the increasing amounts of data…

Computer Vision and Pattern Recognition · Computer Science 2026-05-07 Julia Dima , Pablo Gómez , Sandor Kruk , Peter Kretschmar , Simon Rosen , Călin-Adrian Popa

Context. Solar Shack-Hartmann wavefront sensors measure differential wavefront tilts as the relative shift between images from different subapertures. There are several methods in use for measuring these shifts. Aims. We evaluate the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Mats G. Löfdahl

Stacking analysis is a means of detecting faint sources using a priori position information to estimate an aggregate signal from individually undetected objects. Confusion severely limits the effectiveness of stacking in deep surveys with…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Peter Kurczynski , Eric Gawiser

Weak lensing shear estimation typically results in per galaxy statistical errors significantly larger than the sought after gravitational signal of only a few percent. These statistical errors are mostly a result of shape-noise -- an…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Ofer M. Springer , Eran O. Ofek , Yair Weiss , Julian Merten

A key contribution to X-ray dark-field (XDF) is X-ray diffusion by sample structures smaller than the imaging system's spatial resolution. However, some XDF techniques report that resolvable sample edges also generate XDF. Speckle-based…

We present predictions for the angular correlation function and redshift distribution for SHADES, the SCUBA HAlf-Degree Extragalactic Survey, which will yield a sample of around 300 sub-mm sources in the 850 micron waveband in two separate…

Metacalibration is a new technique for measuring weak gravitational lensing shear that is unbiased for isolated galaxy images. In this work we test metacalibration with overlapping, or ``blended'' galaxy images. Using standard…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-28 Erin S. Sheldon , Matthew R. Becker , Niall MacCrann , Michael Jarvis

Massively multiplexed spectrographs will soon gather large statistical samples of stellar spectra. The accurate estimation of uncertainties on derived parameters, such as line-of-sight velocity $v_\mathrm{los}$, especially for spectra with…

Instrumentation and Methods for Astrophysics · Physics 2024-07-23 László Dobos , Alexander S. Szalay , Tamás Budavári , Evan N. Kirby , Robert H. Lupton , Rosemary F. G. Wyse

Power grids serve as a vital component in numerous industries, seamlessly delivering electrical energy to industrial processes and technologies, making their safe and reliable operation indispensable. However, powerlines can be hard to…

Computer Vision and Pattern Recognition · Computer Science 2024-09-26 Maximilian Andreas Hoefler , Karsten Mueller , Wojciech Samek

The price of instruments and observing time on modern telescopes is quickly increasing with the size of the primary mirror. Therefore, it is worth revisiting the data reduction algorithms to extract every bit of scientific information from…

Instrumentation and Methods for Astrophysics · Physics 2021-02-03 Nikolai Piskunov , Ansgar Wehrhahn , Thomas Marquart

Weak lensing by large-scale structure is a powerful probe of cosmology if the apparent alignments in the shapes of distant galaxies can be accurately measured. Most studies have therefore focused on improving the fidelity of the shape…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Henk Hoekstra , Arun Kannawadi , Thomas D. Kitching

When a coherent laser beam impinges on a random sample (e.g. a colloidal suspension), the scattered light exhibits characteristic speckles. If the temporal coherence of the light source is too short, then the speckles disappear, along with…

Optics · Physics 2011-12-13 D. Brogioli , D. Salerno , F. Croccolo , R. Ziano , F. Mantegazza

Grazing incidence mirrors for X-ray astronomy are usually designed in the parabola-hyperbola (Wolter I) configuration. This design allows for optimal images on-axis, which however degrade rapidly with the off-axis angle. Mirror surfaces…

Astrophysics · Physics 2009-11-06 Paolo Conconi , Sergio Campana

We present a joint weak lensing and X-ray analysis of 4 deg$^2$ from the CFHTLS and XMM-LSS surveys. Our weak lensing analysis is the first analysis of a real survey using shapelets, a new generation weak lensing analysis method. We create…

Object detection aims to localize and classify the objects in a given image, and these two tasks are sensitive to different object regions. Therefore, some locations predict high-quality bounding boxes but low classification scores, and…

Computer Vision and Pattern Recognition · Computer Science 2022-05-03 Yang Yang , Min Li , Bo Meng , Junxing Ren , Degang Sun , Zihao Huang
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