English
Related papers

Related papers: Mitigating antenna gain errors with HyFoReS in CHI…

200 papers

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

Measurement of redshifted 21-cm emission from neutral hydrogen promises to be the most effective method for studying the reionisation history of hydrogen and, indirectly, the first galaxies. These studies will be limited not by raw…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-24 Paul M. Geil , B. M. Gaensler , J. Stuart B. Wyithe

Cross-correlation between the redshifted 21 cm signal and Lyman-{\alpha} emitters (LAEs) is powerful tool to probe the Epoch of Reionization (EoR). Although the cross-power spectrum (PS) has an advantage of not correlating with foregrounds…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-25 S. Yoshiura , J. L. B. Line , K. Kubota , K. Hasegawa , K. Takahashi

Observations of the 21 cm signal face significant challenges due to bright astrophysical foregrounds that are several orders of magnitude higher than the brightness of the hydrogen line, along with various systematics. Successful 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-11 Chuneeta D. Nunhokee , Dev Null , Cathryn M. Trott , Christopher H. Jordan , Jack B. Line , Randall Wayth , Nichole Barry

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…

Detecting and characterizing the Epoch of Reionization and Cosmic Dawn via the redshifted 21-cm hyperfine line of neutral hydrogen will revolutionize the study of the formation of the first stars, galaxies, black holes and intergalactic gas…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 F. G. Mertens , A. Ghosh , L. V. E. Koopmans

Systematic effects that limit the achievable sensitivity of current low-frequency radio telescopes to the 21 cm signal are among the foremost challenges in observational 21 cm cosmology. The standard approach to retrieving the 21 cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 S. Munshi , L. V. E. Koopmans , F. G. Mertens , A. R. Offringa , S. A. Brackenhoff , E. Ceccotti , J. K. Chege , L. Y. Gao , S. Ghosh , M. Mevius , S. Zaroubi

We introduce a new implementation of the FastICA algorithm on simulated LOFAR EoR data with the aim of accurately removing the foregrounds and extracting the 21-cm reionization signal. We find that the method successfully removes the…

Before it becomes a sensitive probe of the Epoch of Reionization, the Dark Ages, and fundamental physics, 21 cm tomography must successfully contend with the issue of foreground contamination. Broadband foreground sources are expected to be…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-16 Adrian Liu , Max Tegmark

We investigate the effect of radio-frequency interference (RFI) excision in estimating the cosmological \hi\ 21 cm power spectrum. Flagging of RFI-contaminated channels results in a non-uniform sampling of the instrumental bandpass…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-27 Arnab Chakraborty , Abhirup Datta , Aishrila Mazumder

A new generation of interferometric instruments is emerging which aim to use intensity mapping of redshifted $21\,$cm radiation to measure the large-scale structure of the Universe at $z\simeq 1-2$ over wide areas of sky. While these…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Martin White , Nikhil Padmanabhan

Multiple instruments are pursuing constraints on dark energy, observing reionization and opening a window on the dark ages through the detection and characterization of the 21cm hydrogen line across the redshift spectrum, from nearby to…

Instrumentation and Methods for Astrophysics · Physics 2016-10-11 Daniel C. Jacobs , Jacob Burba , Judd Bowman , Abraham R. Neben , Benjamin Stinnett , Lauren Turner

The 21 cm intensity mapping provides a promising probe of the large-scale structure. Astrophysical foregrounds, as the main source of contamination to the cosmological 21 cm signal, persist in a wedge-like region of Fourier space due to the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-04 Kaifeng Yu , Xin Wang

Detecting the cosmological sky-averaged (global) 21 cm signal as a function of observed frequency will provide a powerful tool to study the ionization and thermal history of the intergalactic medium (IGM) in the early Universe ($\sim$ 400…

Instrumentation and Methods for Astrophysics · Physics 2019-09-30 Bang D. Nhan , David D. Bordenave , Richard F. Bradley , Jack O. Burns , Keith Tauscher , David Rapetti , Patricia J. Klima

The James Webb Space Telescope is orders of magnitude more sensitive than any other facility across the near to mid-infrared wavelengths. Many approved programs take advantage of its highly stable point spread function (PSF) to directly…

One of the most promising probes to complement current standard cosmological surveys is the HI intensity map, i.e. the distribution of temperature fluctuations in neutral hydrogen. In this paper we present calculations of the 2-point…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-24 Anut Sangka , David Bacon

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) will measure the 21 cm emission of astrophysical neutral hydrogen to probe large scale structure at redshifts z=0.8-2.5. However, detecting the 21 cm signal beneath substantially…

The removal of the Galactic and extragalactic foregrounds remains a major challenge for those wishing to make a detection of the Epoch of Reionization 21-cm signal. Multiple methods of modelling these foregrounds with varying levels of…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-13 Emma Chapman , Saleem Zaroubi , Filipe Abdalla , Fred Dulwich , Vibor Jelić , Benjamin Mort

Time-dependent and systematic variations in band gain and central frequencies of instruments used to study the Cosmic Microwave Background are important factors in the data-to-map analysis pipeline. If not properly characterized, they could…

Instrumentation and Methods for Astrophysics · Physics 2018-07-25 J. T. Ward , D. Alonso , J. Errard , M. J. Devlin , M. Hasselfield

Extracting parameters from the global 21cm signal is crucial for understanding the early Universe. However, detecting the 21cm signal is challenging due to the brighter foreground and associated observational difficulties. In this study, we…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-16 Anshuman Tripathi , Abhirup Datta , Gursharanjit Kaur
‹ Prev 1 4 5 6 7 8 10 Next ›