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Related papers: Wavelet-Based Techniques for the Gamma-Ray Sky

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We analyze the gamma-ray sky at energies of 0.5 to 50 GeV using the undecimated wavelet transform on the sphere. Focusing on the inner $60^{\circ} \times 60^{\circ}$ of the sky, we identify and characterize four separate residuals beyond…

High Energy Astrophysical Phenomena · Physics 2018-08-15 Bhaskaran Balaji , Ilias Cholis , Patrick J. Fox , Samuel D. McDermott

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-quality astronomical images delivered by modern ground-based and space observatories demand adequate, reliable software for their analysis and accurate extraction of sources, filaments, and other structures, containing massive amounts…

Instrumentation and Methods for Astrophysics · Physics 2021-05-26 A. Men'shchikov

Accurate quantitative mapping of gamma-ray sources is critical for applications ranging from radiological emergency response and environmental monitoring to nuclear security and deep space exploration. Here, we show that integrating…

Instrumentation and Detectors · Physics 2026-02-03 David Breitenmoser , Alberto Stabilini , Malgorzata Magdalena Kasprzak , Sabine Mayer

We propose a new way to observe cosmic-ray-induced air showers by imaging the radio emission. With simulations we demonstrate key features for imaging the radio-wave emission from air showers, which show similarities to the well-established…

High Energy Astrophysical Phenomena · Physics 2026-05-18 Juan Ammerman-Yebra , Harm Schoorlemmer , Anne Timmermans , Sebastian Achim Mueller

The details of an image with noise may be restored by removing noise through a suitable image de-noising method. In this research, a new method of image de-noising based on using median filter (MF) in the wavelet domain is proposed and…

Multimedia · Computer Science 2017-03-21 Afrah Ramadhan , Firas Mahmood , Atilla Elci

If dark matter is composed of neutralinos, one of the most exciting prospects for its detection lies in observations of the gamma-ray radiation created in pair annihilations between neutralinos, a process that may contribute significantly…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-08 Jesus Zavala , Volker Springel , Michael Boylan-Kolchin

X-ray spectroscopy is a powerful technique for the analysis of the energy distribution of X-rays from astrophysical sources. It allows for the study of the properties, composition, and physical processes taking place at the site of…

High Energy Astrophysical Phenomena · Physics 2023-09-22 L. Ducci , C. Malacaria

We present a refinement of the wavelet analysis technique for the detection and characterisation of small scale features embedded in a strongly varying background. This technique handles with particular care the side effects of…

Astrophysics · Physics 2007-05-23 D. Lazzati , S. Campana , P. Rosati , G. Chincarini , R. Giacconi

We construct the spin flaglet transform, a wavelet transform to analyze spin signals in three dimensions. Spin flaglets can probe signal content localized simultaneously in space and frequency and, moreover, are separable so that their…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-20 Boris Leistedt , Jason D. McEwen , Thomas D. Kitching , Hiranya V. Peiris

Clusters of galaxies and the large scale filaments that connect neighboring clusters are expected to be sites of acceleration of charged particles and sources of non-thermal radiation from radio frequencies to gamma rays. Gamma rays are…

Astrophysics · Physics 2009-11-13 Pasquale Blasi , Stefano Gabici , Gianfranco Brunetti

Despite the influx of unprecedented-quality data from the Fermi Gamma-Ray Space Telescope that have been collected over nine years of operation, the contribution of normal star-forming galaxies to the extragalactic gamma-ray background…

High Energy Astrophysical Phenomena · Physics 2018-12-19 I. Komis , V. Pavlidou , A. Zezas

We demonstrate spectroscopy of incoherent light with sub-diffraction resolution. In a proof-of-principle experiment we analyze the spectrum of a pair of incoherent point-like sources whose separation is below the diffraction limit. The two…

Scattering obscures information carried by wave by producing a speckle pattern, posing a common challenge across various fields, including microscopy and astronomy. Traditional methods for extracting information from speckles often rely on…

The neutral hydrogen 21cm line is potentially a very powerful probe of the observable universe, and a number of on-going experiments are trying to detect it at cosmological distances. However, the presence of strong foreground radiations…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Qizhi Huang , Fengquan Wu , Xuelei Chen

We construct a directional spin wavelet framework on the sphere by generalising the scalar scale-discretised wavelet transform to signals of arbitrary spin. The resulting framework is the only wavelet framework defined natively on the…

Information Theory · Computer Science 2017-06-06 Jason D. McEwen , Boris Leistedt , Martin Büttner , Hiranya V. Peiris , Yves Wiaux

The deflection of ultra-high energy cosmic rays depends on the shape of the injection spectrum of the source and the pervasive cosmic magnetic fields. In this work it is applied the wavelet transform on the sphere to search for energy…

Instrumentation and Methods for Astrophysics · Physics 2012-04-03 Rafael Alves Batista , Marcelo Zimbres , Ernesto Kemp

The wavelet spectra is a common starting point for estimating the Hurst exponent of a self-similar signal using wavelet-based techniques. The decay of the $\log_2$ average energy of the detail wavelet coefficients as a function of the level…

Methodology · Statistics 2025-12-02 Raymond J. Hinton, , Pepa Ramírez Cobo , Brani Vidakovic

A brief review of the indirect detection signatures of dark matter is given. In particular, detection methods of dark matter particle annihilation to antimatter and gamma-rays are reviewed. With the GLAST satellite soon to be launched, a…

Astrophysics · Physics 2008-11-26 Lars Bergstrom

Wavelets provide the flexibility to analyse stochastic processes at different scales. Here, we apply them to multivariate point processes as a means of detecting and analysing unknown non-stationarity, both within and across data streams.…

Methodology · Statistics 2020-11-04 Edward A. K. Cohen , Alexander J. Gibberd