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Related papers: A Clustered Extragalactic Foreground Model for the…

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In the context of clustering, we assume a generative model where each cluster is the result of sampling points in the neighborhood of an embedded smooth surface; the sample may be contaminated with outliers, which are modeled as points…

Machine Learning · Statistics 2011-11-30 Ery Arias-Castro , Guangliang Chen , Gilad Lerman

This paper presents scale-adaptive filters that optimize the detection/separation of compact sources on a background. We assume that the sources have a multiquadric profile, i. e. $\tau (x) = {[1 + {(x/r_c)}^2]}^{-\lambda}, \lambda \geq…

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

XMM-Newton provides unprecedented insight into the X-ray Universe, recording variability information for hundreds of thousands of sources. Manually searching for interesting patterns in light curves is impractical, requiring an automated…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Miloš Kovačević , Mario Pasquato , Martino Marelli , Andrea De Luca , Ruben Salvaterra , Andrea Belfiore Mondoni

The cross-correlation between the cosmic microwave background (CMB) fields and matter tracers carries important cosmological information. In this paper, we forecast by a signal-to-noise ratio analysis the information contained in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-10 José R. Bermejo-Climent , Mario Ballardini , Fabio Finelli , Daniela Paoletti , Roy Maartens , José A. Rubiño-Martin , Luca Valenziano

The origin of the nonthermal EUV and hard X-ray emission "excess" reported from some galaxy clusters has been intensively debated over last several years. The most favored models which refer this excess to relativistic electrons…

Astrophysics · Physics 2009-11-07 A. N. Timokhin , F. A. Aharonian , A. Yu. Neronov

The identification of ultra-high energy cosmic ray sources is one of the open challenges of high-energy astrophysics. As charged particles travel through the Universe, they are deflected by extragalactic magnetic fields and lose energy…

High Energy Astrophysical Phenomena · Physics 2026-05-05 Nadine Bourriche , Francesca Capel , Nicole Hartmann

We present improved synthesis models of the evolving spectrum of the UV/X-ray diffuse background, updating and extending our previous results. A "minimal cosmic reionization model" is presented in which the galaxy UV emissivity traces…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-29 Francesco Haardt , Piero Madau

Extragalactic foregrounds are known to generate significant biases in temperature-based CMB lensing reconstruction. Several techniques, which include ``source hardening'' and ``shear-only estimators'' have been proposed to mitigate…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-24 Noah Sailer , Simone Ferraro , Emmanuel Schaan

Far-infrared maps obtained with ISOPHOT have been searched for point-like sources. The majority of the 55 sources is believed to be extragalactic and in most cases no previously known sources can be associated with them. Based on the…

Astrophysics · Physics 2007-05-23 M. Juvela , K. Mattila , D. Lemke

Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-23 Eleonora Vanzan , Alvise Raccanelli , Nicola Bartolo

We examine the gravitational lensing effect of a foreground galaxy cluster on the number count statistics of background X-ray sources. The lensing produces a deficit in the number of resolved sources in a ring close to the critical radius…

Astrophysics · Physics 2007-05-23 Alexandre Refregier , Abraham Loeb

Clustering is the task of gathering similar data samples into clusters without using any predefined labels. It has been widely studied in machine learning literature, and recent advancements in deep learning have revived interest in this…

Machine Learning · Computer Science 2023-09-04 Mohammadreza Sadeghi , Hadi Hojjati , Narges Armanfard

In the near future, the overlap of the Rubin Observatory Legacy Survey of Space and Time (LSST) and the Simons Observatory (SO) will present an ideal opportunity for joint cosmological dataset analyses. In this paper we simulate the joint…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-06 Xiao Fang , Tim Eifler , Emmanuel Schaan , Hung-Jin Huang , Elisabeth Krause , Simone Ferraro

One of the critical challenges facing imaging studies of the 21-cm signal at the Epoch of Reionization (EoR) is the separation of astrophysical foreground contamination. These foregrounds are known to lie in a wedge-shaped region of…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Samuel Gagnon-Hartman , Yue Cui , Jacob Kennedy , Adrian Liu , Siamak Ravanbakhsh

We analyse the clustering of cosmic large scale structure using a consistent modified gravity perturbation theory, accounting for anisotropic effects along and transverse to the line of sight. The growth factor has a particular scale…

Galaxy clusters are one of the most powerful probes to study extensions of General Relativity and the Standard Cosmological Model. Upcoming surveys like the Vera Rubin Observatory's Legacy Survey of Space and Time are expected to…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-19 Markus Michael Rau , Florian Kéruzoré , Nesar Ramachandra , Lindsey Bleem

To make a power spectrum (PS) detection of the 21 cm signal from the Epoch of Reionisation (EoR), one must avoid/subtract bright foreground sources. Sources such as Fornax A present a modelling challenge due to spatial structures spanning…

Instrumentation and Methods for Astrophysics · Physics 2020-07-22 J. L. B. Line , D. A. Mitchell , B. Pindor , J. L. Riding , B. McKinley , R. L. Webster , C. M. Trott , N. Hurley-Walker , A. R. Offringa

We review estimates of small scale fluctuations due to extragalactic point sources in the Planck Surveyor frequency bands. While our undestanding of the spectral and evolutionary properties of these sources is far from complete,…

Astrophysics · Physics 2007-05-23 G. De Zotti , L. Toffolatti , G. L. Granato

Nearby galaxies provide populations of stellar and non-stellar sources at a common distance and in quantifiable environments. All are observed through the Milky Way foreground, with varying degrees of contamination that depend on observed…

Astrophysics of Galaxies · Physics 2024-09-05 P. Barmby

A soft X-ray excess has been claimed to exist in and around a number of galaxy clusters and this emission has been attributed to the warm-hot intergalactic medium that may constitute most of the baryons in the local universe. We have…

Astrophysics · Physics 2009-11-11 J. N. Bregman , E. J. Lloyd-Davies
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