English
Related papers

Related papers: Wavelets Applied to the Detection of Point Sources…

200 papers

In this work we analyze the effect of smoothing maps containing arrival directions of cosmic rays with a gaussian kernel and kernels of the mexican hat wavelets of orders 1, 2 and 3. The analysis is performed by calculating the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Rafael Alves Batista , Ernesto Kemp , Bruno Daniel

An analysis of the sensitivity of gaussian and mexican hat wavelet family filters to the detection of point sources of ultra-high energy cosmic rays was performed. A source embedded in a background was simulated and the number of events and…

Instrumentation and Methods for Astrophysics · Physics 2012-03-26 Rafael Alves Batista , Ernesto Kemp , Bruno Daniel

It is the aim of this paper to introduce the use of isotropic wavelets to detect and determine the flux of point sources appearing in CMB maps. The most suited wavelet to detect point sources filtered with a Gaussian beam is the Mexican…

This paper considers filters (the Mexican hat wavelet, the matched and the scale-adaptive filters) that optimize the detection/separation of point sources on a background. We make a one-dimensional treatment, we assume that the sources have…

Astrophysics · Physics 2009-11-07 R. B. Barreiro , J. L. Sanz , D. Herranz , E. Martinez-Gonzalez

Due to the action of the intervening cosmic magnetic fields, ultra-high energy cosmic rays (UHECRs) can be deflected in such a way as to create clustered energy-ordered filamentary structures in the arrival direction of these particles, the…

Instrumentation and Methods for Astrophysics · Physics 2013-12-11 M. Zimbres , R. Alves Batista , E. Kemp

We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be…

Astrophysics · Physics 2009-10-31 L. Tenorio , A. H. Jaffe , S. Hanany , C. H. Lineweaver

In this draft we comment on the results concerning the performances of matched filters, scale adaptive filters and Mexican hat wavelet that recently appeared in literature in the context of point source detection in Cosmic Microwave…

Astrophysics · Physics 2009-11-07 Roberto Vio , Paola Andreani , Willelm Wamsteker

The arrival directions of ultrahigh energy cosmic rays (UHECRs) may show anisotropies on all scales, from just above the experimental angular resolution up to medium scales and dipole anisotropies. We find that a global comparison of the…

We study the spherical Mexican hat wavelet (SMHW) as a detector of primordial non-Gaussianity of the local type on the Cosmic Microwave Background (CMB) anisotropies. For this purpose we define third order statistics based on the wavelet…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 A. Curto , E. Martinez-Gonzalez , R. B. Barreiro

We propose a new detection technique in the plane based on an isotropic wavelet family. This family is naturally constructed as an extension of the Gaussian-Mexican Hat Wavelet pair and for that reason we call it the Mexican Hat Wavelet…

When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new…

Astrophysics · Physics 2012-08-27 The Pierre Auger Collaboration

This article considers the detection of point sources in two dimensional astronomical images. The detection scheme we propose is based on peak statistics. We discuss the example of the detection of far galaxies in Cosmic Microwave…

Astrophysics · Physics 2009-11-10 M. Lopez-Caniego , D. Herranz , J. L. Sanz , R. B. Barreiro

The distribution of ultra-high-energy cosmic-ray arrival directions appears to be nearly isotropic except for a dipole moment of order $6 \times (E/10~\mathrm{EeV})$ per cent. Nonetheless, at the highest energies, as the number of possible…

The spherical Mexican Hat wavelet is introduced in this paper, with the aim of testing the Gaussianity of the Cosmic Microwave Background temperature fluctuations. Using the information given by the wavelet coefficients at several scales,…

Our latest paper investigates the effects of UHECR propagation in a turbulent intergalactic magnetic field in the small-angle scattering regime, specifically focusing on the non-trivial caustic-like pattern that arises with strong deviation…

High Energy Astrophysical Phenomena · Physics 2024-12-03 K. Dolgikh , A. Korochkin , G. Rubtsov , D. Semikoz , I. Tkachev

We present a Bayesian hierarchical model which enables a joint fit of the ultra-high-energy cosmic ray (UHECR) energy spectrum and arrival directions within the context of a physical model for the UHECR phenomenology. In this way, possible…

High Energy Astrophysical Phenomena · Physics 2019-02-04 Francesca Capel , Daniel J. Mortlock

A directional spherical wavelet analysis is performed to examine the Gaussianity of the WMAP 1-year data. Such an analysis is facilitated by the introduction of a fast directional continuous spherical wavelet transform. The directional…

Astrophysics · Physics 2008-03-04 J. D. McEwen , M. P. Hobson , A. N. Lasenby , D. J. Mortlock

We present results of elaborate four-dimensional simulations of the propagation of ultra-high-energy cosmic rays (UHECR), which are based on a realistic astrophysical scenario. The distribution of the arrival directions of the UHECR is…

High Energy Astrophysical Phenomena · Physics 2018-02-19 David Wittkowski , Karl-Heinz Kampert

The search of a clustering signal in the arrival directions of ultra-high-energy cosmic rays (UHECRs) is a standard method to assess the level of anisotropy of the data sets under investigation. Here, we first show how to quantify the…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Guillaume Decerprit , Nicolas G. Busca , Etienne Parizot

Point-source contamination in high-precision Cosmic Microwave Background (CMB) maps severely affects the precision of cosmological parameter estimates. Among the methods that have been proposed for source detection, wavelet techniques based…

Astrophysics · Physics 2009-11-07 R. Vio , L. Tenorio , W. Wamsteker
‹ Prev 1 2 3 10 Next ›