English
Related papers

Related papers: Simulated multi-tracer analyses with HI intensity …

200 papers

Increasingly large areas in cosmic shear surveys lead to a reduction of statistical errors, necessitating to control systematic errors increasingly better. One of these systematic effects was initially studied by Hartlap et al. in 2011,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Eray Genc , Peter Schneider , Sandra Unruh , Tim Schrabback

21-cm intensity mapping (IM) is a powerful technique to probe the large-scale distribution of neutral hydrogen (HI) and extract cosmological information such as the baryon acoustic oscillation feature. A key challenge lies in recovering the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Zitong Wang , Feng Shi , Le Zhang , Yanming Liu , Xiaoping Li , Shulei Ni , Ming Jiang , Xiaofan Ma

Intensity mapping provides a unique means to probe the epoch of reionization (EoR), when the neutral intergalactic medium was ionized by the energetic photons emitted from the first galaxies. The [CII] 158$\mu$m fine-structure line is…

Techniques using multiple tracers of the large scale structure of the universe show great promise for examining the fundamentals of our Universe's cosmology. Such techniques rely on the different relationship between the overdensity of…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-04 Brandon Venville , Anna Bonaldi , David Parkinson , Natasha Hurley-Walker , Tim Galvin , Nick Seymour

In the neutral hydrogen (HI) intensity mapping (IM) survey, the foreground contamination on the cosmological signals is extremely severe, and the systematic effects caused by radio telescopes themselves further aggravate the difficulties in…

Instrumentation and Methods for Astrophysics · Physics 2022-07-28 Shulei Ni , Yichao Li , Li-Yang Gao , Xin Zhang

Twenty-one centimeter tomography is emerging as a powerful tool to explore the end of the cosmic dark ages and the reionization epoch, but it will only be as good as our ability to accurately model and remove astrophysical foreground…

Astrophysics · Physics 2008-11-26 Xiaomin Wang , Max Tegmark , Mario Santos , Lloyd Knox

We compare multiple foreground-cleaning pipelines for estimating the tensor-to-scalar ratio, $r$, using simulated maps of the planned CMB-S4 experiment within the context of the South Pole Deep Patch. To evaluate robustness, we analyze bias…

21 cm intensity mapping has emerged as a promising technique to map the large-scale structure of the Universe. However, the presence of foregrounds with amplitudes orders of magnitude larger than the cosmological signal constitutes a…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-30 Isabella P. Carucci , Melis O. Irfan , Jérôme Bobin

Extracting the neutral hydrogen (HI) signal is a great challenge for cosmological 21cm experiments, both the astrophysical foregrounds and the receiver noise are typically several orders of magnitude greater than the 21cm signal. However,…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Qizhi Huang , Fengquan Wu , Reza Ansari , Xuelei Chen

We investigate the cross-correlation between the spatial distribution of Lyman Break Galaxies (LBGs) and the 21cm intensity mapping signal at $z\sim[3-5]$. At these redshifts, galactic feedback is supposed to only marginally affect the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 Francisco Villaescusa-Navarro , Matteo Viel , David Alonso , Kanan K. Datta , Philip Bull , Mario G. Santos

This study investigates the estimation of the neutral hydrogen (HI) mass function (HIMF) using a Bayesian stacking approach with simulated data for the Five-hundred-meter Aperture Spherical radio Telescope (FAST) HI intensity mapping (HIIM)…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Jiaxin Wang , Yichao Li , Hengxing Pan , Furen Deng , Diyang Liu , Wenxiu Yang , Wenkai Hu , Yougang Wang , Xin Zhang , Xuelei Chen

Foreground removal remains an ongoing challenge in radio cosmology, and increasingly sensitive experiments necessitate more robust analysis techniques. In this work, we model simulated data from a single-dish intensity mapping experiment,…

Instrumentation and Methods for Astrophysics · Physics 2026-04-30 Geoff G. Murphy , Philip Bull , Mario G. Santos , Zheng Zhang , Steven Cunnington

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

Direct detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 F. Mertens , A. Ghosh , L. V. E. Koopmans

In a sky-averaged 21-cm signal experiment, the uncertainty on the extracted signal depends mainly on the covariance between the foreground and 21-cm signal models. In this paper, we construct these models using the modes of variation…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 Anchal Saxena , P. Daniel Meerburg , Eloy de Lera Acedo , Will Handley , Léon V. E. Koopmans

Hybrid Foreground Residual Subtraction (HyFoReS) is a new family of algorithms designed to remove systematics-induced foreground contamination for 21-cm intensity mapping data. Previously, the algorithm was shown to be effective in…

Instrumentation and Methods for Astrophysics · Physics 2025-06-12 Haochen Wang , Panupong Phoompuang , Kiyoshi W. Masui , Arnab Chakraborty , Simon Foreman

Imaging surveys of galaxies will have a high number density and angular resolution yet a poor redshift precision. Intensity maps of neutral hydrogen (HI) will have accurate redshift resolution yet will not resolve individual sources. Using…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-23 David Alonso , Pedro G. Ferreira , Matt J. Jarvis , Kavilan Moodley

Intensity mapping of the HI brightness temperature provides a unique way of tracing large-scale structures of the Universe up to the largest possible scales. This is achieved by using a low angular resolution radio telescopes to detect…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-02 Obinna Umeh

Galaxy redshift surveys are one of the key probes in modern cosmology. In the data analysis of galaxy surveys, the precision of the statistical measurement is primarily limited by the cosmic variance on large scales. Fortunately, this…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-27 Yuting Wang , Gong-Bo Zhao

Subtraction of astrophysical foreground contamination from "dirty" sky maps produced by simulated measurements of the Murchison Widefield Array (MWA) has been performed by fitting a 3rd-order polynomial along the spectral dimension of each…

Astrophysics · Physics 2011-02-11 Judd D. Bowman , Miguel F. Morales , Jacqueline N. Hewitt