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The Hubble Space Telescope (HST) has been operational for over 30 years and throughout that time it has been bombarded by high energy charged particles colloquially referred to as cosmic rays. In this paper, we present a comprehensive study…

Instrumentation and Methods for Astrophysics · Physics 2021-09-22 Nathan Miles , Susana E. Deustua , Gonzalo Tancredi , German Schnyder , Sergio Nesmachnow , Geoffrey Cromwell

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

Detecting edges is a fundamental problem in computer vision with many applications, some involving very noisy images. While most edge detection methods are fast, they perform well only on relatively clean images. Indeed, edges in such…

Computer Vision and Pattern Recognition · Computer Science 2021-10-06 Nati Ofir , Meirav Galun , Boaz Nadler , Ronen Basri

Line discontinuities in cosmic microwave background anisotropy maps are a distinctive prediction of models with cosmic strings. These signatures are visible in anisotropy maps with good angular resolution and should be identifiable using…

Astrophysics · Physics 2009-06-23 Stephen Amsel , Joshua Berger , Robert H. Brandenberger

We introduce a closed-form method for identification of discrete-time linear time-variant systems from data, formulating the learning problem as a regularized least squares problem where the regularizer favors smooth solutions within a…

Optimization and Control · Mathematics 2022-05-31 Maria Carvalho , Claudia Soares , Pedro Lourenço , Rodrigo Ventura

Accurate automatic identification of astronomical objects in an imperfect world of non-linear wide-angle optics, imperfect optics, inaccurately pointed telescopes, and defect-ridden cameras is not always a trivial first step. In the past…

Astrophysics · Physics 2009-11-10 Lior Shamir , Robert J. Nemiroff

Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has…

Astrophysics · Physics 2010-01-15 Paul Sommers , Stefan Westerhoff

We describe a system that builds a high dynamic-range and wide-angle image of the night sky by combining a large set of input images. The method makes use of pixel-rank information in the individual input images to improve a "consensus"…

Computer Vision and Pattern Recognition · Computer Science 2014-06-09 Dustin Lang , David W. Hogg , Bernhard Scholkopf

We propose to use a simple observable, the fractional area of "hot spots" in weak gravitational lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-convergence…

Astrophysics · Physics 2011-02-11 Sheng Wang , Zoltán Haiman , Morgan May

Cosmography is a phenomenological and relatively model-independent approach to cosmology, where physical quantities are expanded as a Taylor series in the cosmological redshift, or in related variables. Here we apply this methodology to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-08 C. J. A. P. Martins , F. P. S. A. Ferreira , P. V. Marto

Although the existence of cosmic rays with energies extending well above $10^{19}$ eV has been confirmed, their origin remains one of the most important questions in astro-particle physics today. Several source models have been proposed for…

Astrophysics · Physics 2011-04-19 B. T. Stokes , C. C. H. Jui , J. N. Matthews

Image subtraction in astronomy is a tool for transient object discovery such as asteroids, extra-solar planets and supernovae. To match point spread functions (PSFs) between images of the same field taken at different times a convolution…

Instrumentation and Methods for Astrophysics · Physics 2013-05-30 Steven Hartung , Hemant Shukla , J. Patrick Miller , Carlton Pennypacker

The latticework structure known as the cosmic web provides a valuable insight into the assembly history of large-scale structures. Despite the variety of methods to identify the cosmic web structures, they mostly rely on the assumption that…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Yikun Zhang , Rafael S. de Souza , Yen-Chi Chen

We present a fast algorithm to produce light curves of distant stars undergoing microlensing near critical curves. The need of these type of algorithms is motivated by recent observations of microlensing events of distant stars at high…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 J. M. Diego

This paper introduces Colossus, a public, open-source python package for calculations related to cosmology, the large-scale structure (LSS) of matter in the universe, and the properties of dark matter halos. The code is designed to be fast…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-20 Benedikt Diemer

We present a method to map the artificial sky brightness across large territories in astronomical photometric bands with a resolution of approximately 1 km. This is useful to quantify the situation of night sky pollution, to recognize…

Astrophysics · Physics 2009-10-31 P. Cinzano , F. Falchi , C. D. Elvidge , K. E. Baugh

We present a data-driven technique to analyze multifrequency images from upcoming cosmological surveys mapping large sky area. Using full information from the data at the two-point level, our method can simultaneously constrain the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 Yun-Ting Cheng , Benjamin D. Wandelt , Tzu-Ching Chang , Olivier Dore

Astronomy depends on ever increasing computing power. Processor clock-rates have plateaued, and increased performance is now appearing in the form of additional processor cores on a single chip. This poses significant challenges to the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Benjamin R. Barsdell , David G. Barnes , Christopher J. Fluke

The spherical harmonic transform is a powerful tool in the analysis of spherical data sets, such as the cosmic microwave background data. In this work, we present a new scheme for the spherical harmonic transforms that supports both CPU and…

Instrumentation and Methods for Astrophysics · Physics 2022-11-18 Chi Tian , Siyu Li , Hao Liu

To maximise data output from single-shot astronomical images, the rejection of cosmic rays is important. We present the results of a benchmark trial comparing various cosmic ray rejection algorithms. The procedures assess relative…

Astrophysics · Physics 2009-11-13 Catherine L. Farage , Kevin A. Pimbblet