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Line intensity mapping (LIM) is a promising observational method to probe large-scale fluctuations of line emission from distant galaxies. Data from wide-field LIM observations allow us to study the large-scale structure of the universe as…

Astrophysics of Galaxies · Physics 2021-01-13 Kana Moriwaki , Masato Shirasaki , Naoki Yoshida

One of the main goals of most future CMB experiments is the precise measurement of CMB B-mode polarization, whose major obstacle is the Galactic foregrounds. In this paper, we evaluate the foreground cleaning performance of the variants of…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-24 Jiazheng Dou , Shamik Ghosh , Larissa Santos , Wen Zhao

The redshifted 21\,cm line is an emerging tool in observational cosmology that can serve as a direct probe of the intergalactic medium throughout the cosmic timeline. However, the observation of the cosmological 21\,cm signal from early…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Samit Kumar Pal , Abhirup Datta , Aishrila Mazumder , Anshuman Tripathi

This paper introduces the data cubes from GHIGLS, deep Green Bank Telescope surveys of the 21-cm line emission of HI in 37 targeted fields at intermediate Galactic latitude. The GHIGLS fields together cover over 1000 square degrees at 9.55'…

PICO is a concept for a NASA probe-scale mission aiming to detect or constrain the tensor to scalar ratio $r$, a parameter that quantifies the amplitude of inflationary gravity waves. We carry out map-based component separation on…

HI intensity mapping is a promising technique to probe large-scale structure, traditionally analyzed via two-point statistics such as the angular power spectrum. This technique has proven very powerful but may miss key non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Pauline Gorbatchev , Jean-Luc Starck , Stefano Camera , Marta Spinelli

In high-energy astronomy, spectro-imaging instruments such as X-ray detectors allow investigation of the spatial and spectral properties of extended sources including galaxy clusters, galaxies, diffuse interstellar medium, supernova…

High Energy Astrophysical Phenomena · Physics 2019-07-24 Adrien Picquenot , Fabio Acero , Jérôme Bobin , Pierre Maggi , Jean Ballet , Gabriel W. Pratt

The aim of this project is to recover the CMB anisotropies maps in temperature and polarized intensity by means of a deep convolutional neural network (CNN) which, after appropiate training, can remove the foregrounds from Planck and…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-29 A. Quintana-Estellés , B. Ruiz-Granados , P. Ruiz-Lapuente

Measuring one-point statistics in redshifted 21 cm intensity maps offers an opportunity to explore non-Gaussian features of the early universe. We assess the impact of instrumental effects on measurements made with the Hydrogen Epoch of…

A goal for pathfinder intensity mapping (IM) surveys will be detecting features in the neutral hydrogen (HI) power spectrum, which serve as conclusive evidence of cosmological signals. Observing such features at the expected scales in HI IM…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-25 Steven Cunnington

Line intensity mapping (LIM) is an emerging technique for probing the large-scale structure (LSS) in the post-reionisation era. This captures the integrated flux of a particular spectral line emission from multiple sources within a patch of…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-30 Manas Mohit Dosibhatla , Suman Majumdar , Chandra Shekhar Murmu , Samit Kumar Pal , Saswata Dasgupta , Satadru Bag , Abhirup Datta

Foreground removal is the most important step in detecting the large-scale redshifted HI 21-cm signal. Modelling foreground spectra is challenging and is further complicated by the chromatic response of the telescope. We present a…

Instrumentation and Methods for Astrophysics · Physics 2017-07-19 Visweshwar Ram Marthi , Suman Chatterjee , Jayaram Chengalur , Somnath Bharadwaj

Principal component analysis (PCA) is a commonly used pattern analysis method that maps high-dimensional data into a lower-dimensional space maximizing the data variance, that results in the promotion of separability of data. Inspired by…

Signal Processing · Electrical Eng. & Systems 2022-06-20 Xiaoqiang Hua , Yusuke Ono , Linyu Peng , Yuting Xu

Foreground subtraction is the biggest challenge for future redshifted 21 cm observations to probe reionization. We use a short GMRT observation at 153 MHz to characterize the statistical properties of the background radiation across ~ one…

Astrophysics · Physics 2009-11-13 SK. Saiyad Ali , Somnath Bharadwaj , Jayaram N. Chengalur

The 21 cm spectral line emission of atomic neutral hydrogen (HI) is one of the primary wavelengths observed in radio astronomy. However, the signal is intrinsically faint and the HI content of galaxies depends on the cosmic environment,…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 J. A. Barkai , M. A. W. Verheijen , E. T. Martínez , M. H. F. Wilkinson

The measurement of the large scale distribution of neutral hydrogen in the late Universe, obtained with radio telescopes through the hydrogen 21cm line emission, has the potential to become a key cosmological probe in the upcoming years. We…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Maria Berti , Marta Spinelli , Matteo Viel

In this work we investigate the Principal Component Analysis (PCA) sensitivity to the velocity power spectrum in high opacity regimes of the interstellar medium (ISM). For our analysis we use synthetic Position-Position-Velocity (PPV) cubes…

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 investigate what role the SKA neutral hydrogen (HI) intensity mapping (IM) sky survey observation will play in weighing neutrinos in cosmology. We use the simulated data of the baryon acoustic oscillation (BAO) measurements from the HI…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-17 Jing-Fei Zhang , Bo Wang , Xin Zhang

Line intensity mapping experiments seek to trace large scale structure by measuring the spatial fluctuations in the combined emission, in some convenient spectral line, from individually unresolved galaxies. An important systematic concern…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-20 Adam Lidz , Jessie Taylor