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Related papers: Tomography of the Galactic free electron density w…

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We forecast future constraints on local-type primordial non-Gaussianity parameter $f_{\rm NL}$ with a photometric galaxy survey by Euclid, a continuum galaxy survey by Square Kilometre Array (SKA), and their combination. We derive a general…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-29 Daisuke Yamauchi , Keitaro Takahashi , Masamune Oguri

The free-free absorption of low frequency radio waves by thermal electrons in the warm ionized medium of our Galaxy becomes very significant at $\lesssim 10$ MHz (ultralong-wavelength), and the absorption strength depends on the radio…

Astrophysics of Galaxies · Physics 2022-12-14 Yanping Cong , Bin Yue , Yidong Xu , Yuan Shi , Xuelei Chen

Recently completed H-Alpha surveys of large portions of the sky can be used to create maps of the free-free intensity distribution at high Galactic latitude that are independent of the spectral fits to the CMB data. This provides an…

Astrophysics · Physics 2007-05-23 R. J. Reynolds , L. M. Haffner

In order to clarify the statistical features of complex networks, the spectral density of adjacency matrices has often been investigated. Adopting a static model introduced by Goh, Kahng and Kim, we analyse the spectral density of complex…

Statistical Mechanics · Physics 2009-11-13 Taro Nagao , G. J. Rodgers

The 21cm line from the spin-flip transition of neutral hydrogen (HI) provides a unique window into the Epoch of Reionization (EoR), the final phase transition of our Universe. The Square Kilometre Array (SKA) enables precise measurements of…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-09 Yannic Pietschke , Caroline Heneka , Tom Schlenker , Ayodele Ore , Benedikt Schosser

In this work we present the first non-linear, non-Gaussian full Bayesian large scale structure analysis of the cosmic density field conducted so far. The density inference is based on the Sloan Digital Sky Survey data release 7, which…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 J. Jasche , F. S. Kitaura , C. Li , T. A. Ensslin

Future observations of 21 cm emission from neutral hydrogen survey will become a promising approach to probe the large scale structure of Universe. In this paper, we investigate the impacts of Square Kilometer Array (SKA) 21 cm observation…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-12 Jing-Fei Zhang , Li-Yang Gao , Dong-Ze He , Xin Zhang

Observations of galaxy clustering are made in redshift space, which results in distortions to the underlying isotropic distribution of galaxies. These redshift-space distortions (RSD) not only degrade important features of the matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Yuchan Wang , Baojiu Li , Marius Cautun

Future Square Kilometre Array (SKA) surveys are expected to generate huge datasets of 21cm maps on cosmological scales from the Epoch of Reionization (EoR). We assess the viability of exploiting machine learning techniques, namely,…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-13 Sultan Hassan , Sambatra Andrianomena , Caitlin Doughty

We revisit the issue of non-parametric gravitational lens reconstruction and present a new method to obtain the cluster mass distribution using strong lensing data without using any prior information on the underlying mass. The method…

Astrophysics · Physics 2009-10-07 J. M. Diego , P. Protopapas , H. B Sandvik , M. Tegmark

A full-sky template map of the Galactic free-free foreground emission component is increasingly important for high sensitivity CMB experiments. We use the recently published \ha data of both the northern and southern skies as the basis for…

Astrophysics · Physics 2009-11-07 C. Dickinson , R. D. Davies , R. J. Davis

We present a study of weak lensing shear measurements for simulated galaxy images at radio wavelengths. We construct a simulation pipeline into which we can input galaxy images of known ellipticity, and with which we then simulate…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Prina Patel , Filipe B. Abdalla , David J. Bacon , Barnaby Rowe , Oleg Smirnov , Rob J. Beswick

This paper develops a nonparametric density estimator with parametric overtones. Suppose $f(x,\theta)$ is some family of densities, indexed by a vector of parameters $\theta$. We define a local kernel smoothed likelihood function which for…

Methodology · Statistics 2026-04-22 Nils Lid Hjort , M. C. Jones

In the recent paper [17] the first experimental determination of the density matrix of a free electron beam has been reported. The employed method leads to a linear inverse problem with a positive semidefinite operator as unknown. The…

Analysis of PDEs · Mathematics 2020-02-19 Cong Shi , Claus Ropers , Thorsten Hohage

Simulating the evolution of the local universe is important for studying galaxies and the intergalactic medium in a way free of cosmic variance. Here we present a method to reconstruct the initial linear density field from an input…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Huiyuan Wang , H. J. Mo , Xiaohu Yang , Y. P. Jing , W. P. Lin

By the time that the first phase of the Square Kilometre Array is deployed it will be able to perform state of the art Large Scale Structure (LSS) as well as Weak Gravitational Lensing (WGL) measurements of the distribution of matter in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-19 Donnacha Kirk , Aurélien Benoit-Lévy , Filipe B. Abdalla , Philip Bull , Benjamin Joachimi

To redetermine the Galactic spiral density wave parameters, we have performed a spectral (Fourier) analysis of the radial velocities for 44 masers with known trigonometric parallaxes, proper motions, and line-of-sight velocities. The masers…

Astrophysics of Galaxies · Physics 2012-08-23 A. T. Bajkova , V. V. Bobylev

The Square-Kilometre-Array (SKA) will be a radio telescope with a collecting area that will exceed that of existing telescopes by a factor of a hundred or so. This contribution summarises one of the key-science projects selected for the…

Astrophysics · Physics 2007-05-23 M. Kramer

We develop a new method which measures the projected density distribution w_p(r_p)n of photometric galaxies surrounding a set of spectroscopically-identified galaxies, and simultaneously the projected correlation function w_p(r_p) between…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Wenting Wang , Y. P. Jing , Cheng Li , Teppei Okumura , Jiaxin Han

When completed the Square Kilometre Array (SKA) will feature an unprecedented rate of image generation. While previous generations of telescopes have relied on human expertise to extract scientifically interesting information from the…

Instrumentation and Methods for Astrophysics · Physics 2016-01-19 C. Hollitt , M. Johnston-Hollitt , S. Dehghan , M. Frean , T. Bulter-Yeoman
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