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21-cm emission from neutral hydrogen during and before the epoch of cosmic reionisation is gravitationally lensed by material at all lower redshifts. Low-frequency radio observations of this emission can be used to reconstruct the projected…

Astrophysics · Physics 2009-06-25 Stefan Hilbert , R. Benton Metcalf , S. D. M. White

We present a study of internal reflection and cross coupling systematics in Phase I of the Hydrogen Epoch of Reionization Array (HERA). In a companion paper, we outlined the mathematical formalism for such systematics and presented…

The Planck space mission has observed the first three rotational lines of emission of Galactic CO. Those maps, however, are either noisy, or contaminated by astrophysical emissions from different origin. We revisit those data products to…

Astrophysics of Galaxies · Physics 2024-08-07 Shamik Ghosh , Mathieu Remazeilles , Jacques Delabrouille

We show that the first 10 eigencomponents of the Karhunen-Lo\`eve expansion or Principal Component Analysis (PCA) provide a robust classification scheme for the identification of stars, galaxies and quasi-stellar objects from multi-band…

Astrophysics · Physics 2009-11-07 Remi A. Cabanac , Valerie de Lapparent , Paul Hickson

We present a general linear algorithm for measuring the surface mass density 1-\kappa from the observable reduced shear g=\gamma/(1-\kappa) in the strong lensing regime. We show that in general, the observed polarization field can be…

Astrophysics · Physics 2009-10-31 Ue-Li Pen

We derive linearly polarized astrophysical component maps in the Northern Sky from the QUIJOTE-MFI data at 11 and 13 GHz in combination with the WMAP K and Ka bands (23 and 33 GHz) and all Planck polarized channels (30-353 GHz), using the…

We present the application of the Fast Independent Component Analysis ({\ica}) technique for blind component separation to polarized astrophysical emission. We study how the Cosmic Microwave Background (CMB) polarized signal, consisting of…

Astrophysics · Physics 2009-06-16 C. Baccigalupi , F. Perrotta , G. De Zotti , G. F. Smoot , C. Burigana , D. Maino , L. Bedini , E. Salerno

Line intensity mapping is a superb tool to study the collective radiation from early galaxies. However, the method is hampered by the presence of strong foregrounds, mostly produced by low-redshift interloping lines. We present here a…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Paolo Comaschi , Andrea Ferrara

We present new clean maps of the CMB temperature anisotropies (as measured by Planck) constructed with a novel internal linear combination (ILC) algorithm using directional, scale-discretised wavelets --- Scale-discretised, directional…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-24 Keir K. Rogers , Hiranya V. Peiris , Boris Leistedt , Jason D. McEwen , Andrew Pontzen

We use Principal Component Analysis (PCA) to study the gas dynamics in numerical simulations of typical MCs. Our simulations account for the non-isothermal nature of the gas and include a simplified treatment of the time-dependent gas…

Solar and Stellar Astrophysics · Physics 2015-06-18 Erik Bertram , Rahul Shetty , Simon C. O. Glover , Ralf S. Klessen , Julia Roman-Duval , Christoph Federrath

Performance of nuclear threat detection systems based on gamma-ray spectrometry often strongly depends on the ability to identify the part of measured signal that can be attributed to background radiation. We have successfully applied a…

Machine Learning · Computer Science 2016-05-30 P. Tandon , P. Huggins , A. Dubrawski , S. Labov , K. Nelson

We introduce the notion of Principal Component Analysis (PCA) of image gradient orientations. As image data is typically noisy, but noise is substantially different from Gaussian, traditional PCA of pixel intensities very often fails to…

Computer Vision and Pattern Recognition · Computer Science 2010-05-18 Georgios Tzimiropoulos , Stefanos Zafeiriou

We apply the Correlated Component Analysis (CCA) method on simulated data of the Square Kilometre Array, with the aim of accurately cleaning the 21 cm reionization signal from diffuse foreground contamination. The CCA has been developed for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Anna Bonaldi , Michael L. Brown

CONTEXT.Large field-of-view imaging/polarimetry instruments operating at millimeter and submm wavelengths are fundamental tools to understand the role of magnetic fields (MF) in channeling filament material into prestellar cores providing a…

Instrumentation and Methods for Astrophysics · Physics 2022-02-02 G. Pisano , A. Ritacco , A. Monfardini , C. Tucker , P. A. R. Ade , A. Shitvov , A. Benoit , M. Calvo , A. Catalano , J. Goupy , S. Leclercq , J. Macias-Perez , A. Andrianasolo , N. Ponthieu

We study the clustering of HI intensity maps produced from simulations with a focus on baryonic acoustic oscillations (BAO) and the effects induced by telescope beam smoothing and foreground cleaning. We start by creating a HI catalogue at…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-13 Santiago Avila , Bernhard Vos-Ginés , Steven Cunnington , Adam R. H. Stevens , Gustavo Yepes , Alexander Knebe , Chia-Hsun Chuang

One of the main obstacles for extracting the Cosmic Microwave Background (CMB) from mm/submm observations is the pollution from the main Galactic components: synchrotron, free-free and thermal dust emission. The feasibility of using simple…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-20 H. U. Nørgaard-Nielsen

The Internal Linear Combination (ILC) is widely used to extract the cosmic microwave background (CMB) signal from multi-frequency observation maps, especially for Satellite experiments with quasi-full sky coverage. We extend ILC method to…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-29 Zirui Zhang , Yang Liu , Si-Yu Li , De-Liang Wu , Haifeng Li , Hong Li

In this chapter, the use of machine learning (ML) in redshifted 21 cm cosmology is discussed, especially for the cosmic dawn, the Epoch of Reionization, and the scientific program of SKA-Low. The 21 cm signal is useful because it can…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-18 Hayato Shimabukuro

Global Navigation Satellite Systems (GNSS) underpin positioning, navigation, and timing (PNT), yet their low-power signals are easily blocked or disrupted, leaving gaps in PNT availability in contested environments (e.g. maritime settings)…

Signal Processing · Electrical Eng. & Systems 2026-05-21 Nisanur Camuzcu , Tiep M. Hoang , Alireza Vahid

We present a detection of 21-cm emission from large-scale structure (LSS) between redshift 0.78 and 1.43 made with the Canadian Hydrogen Intensity Mapping Experiment (CHIME). Radio observations acquired over 102 nights are used to construct…

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