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Instruments targeting 21~cm emission at high redshifts need a spectral dynamic range of better than ten thousand to distinguish the 21~cm background against bright foregrounds. Systematics arising from the antenna pattern are a leading…

Instrumentation and Methods for Astrophysics · Physics 2026-05-21 Daniel C. Jacobs

We present an improved Global Sky Model (GSM) of diffuse galactic radio emission from 10 MHz to 5 THz, whose uses include foreground modeling for CMB and 21 cm cosmology. Our model improves on past work both algorithmically and by adding…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-05 Haoxuan Zheng , Max Tegmark , Joshua S. Dillon , Doyeon A. Kim , Adrian Liu , Abraham Neben , Justin Jonas , Patricia Reich , Wolfgang Reich

Foreground removal techniques for CMB analyses make specific assumptions about the properties of foregrounds in temperature and in polarization. By investigating the statistics of foreground components more understanding about the degree to…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 Sebastian von Hausegger , Aske Gammelgaard Ravnebjerg , Hao Liu

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

The redshifted 21-cm background is expected to be a powerful probe of the early Universe, carrying both cosmological and astrophysical information from a wide range of redshifts. In particular, the power spectrum of fluctuations in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Anastasia Fialkov , Rennan Barkana , Aviad Cohen

In the context of maximum-likelihood parametric component separation for next-generation full-sky CMB polarization experiments, we study the impact of fitting different spectral parameters of Galactic foregrounds in distinct subsets of…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-14 Arianna Rizzieri , Clément Leloup , Josquin Errard , Davide Poletti

The near-infrared background between 0.5 $\mu$m to 2 $\mu$m contains a wealth of information related to radiative processes in the universe. Infrared background anisotropies encode the redshift-weighted total emission over cosmic history,…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Chang Feng , Asantha Cooray , Jamie Bock , Tzu-Ching Chang , Olivier Doré , Mario G. Santos , Marta B. Silva , Michael Zemcov

We develop an effective perturbation theory (and, equivalently, a bias expansion) for the inhomogeneous 21cm radiation field from reionization. Using large-scale simulations of cosmological reionization, we find that this expansion…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-20 Matthew McQuinn , Anson D'Aloisio

Polarization induced by cosmological scalar perturbations leads to a typical anisotropy pattern, which can best be analyzed in Fourier domain. This allows one to unambiguously distinguish cosmological signal of polarization from other…

Astrophysics · Physics 2009-10-28 Uros Seljak

New low frequency radio telescopes currently being built open up the possibility of observing the 21-cm radiation before the Epoch of Reionization in the future, in particular at redshifts 200 > z > 30, also known as the dark ages. At these…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-03 Rishi Khatri , Benjamin D. Wandelt

Using the Cosmic Background Imager, a 13-element interferometer array operating in the 26-36 GHz frequency band, we have observed 40 sq deg of sky in three pairs of fields, each ~ 145 x 165 arcmin, using overlapping pointings (mosaicing).…

21 cm power spectrum observations have the potential to revolutionize our understanding of the Epoch of Reionization and Dark Energy, but require extraordinarily precise data analysis methods to separate the cosmological signal from the…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-31 Miguel F. Morales , Adam Beardsley , Jonathan Pober , Nichole Barry , Bryna Hazelton , Daniel Jacobs , Ian Sullivan

Future high redshift 21-cm experiments will suffer from a high degree of contamination, due both to astrophysical foregrounds and to non-astrophysical and instrumental effects. In order to reliably extract the cosmological signal from the…

We evaluate the expected level of foreground contamination to the cosmic microwave background (CMB) polarised radiation, focusing on the diffuse emission from our own Galaxy. In particular, we perform a first attempt to simulate an all sky…

Astrophysics · Physics 2015-06-24 Carlo Baccigalupi

Observation of the 21cm line signal from neutral hydrogen during the Epoch of Reionization is challenging due to extremely bright Galactic and extragalactic foregrounds and complicated instrumental calibration. A reasonable approach for…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 S. Yoshiura , K. Ichiki , B. Pindor , K. Takahashi , H. Tashiro , C. M. Trott

Recent developments in the search for inflationary gravitational waves in the cosmic microwave background (CMB) polarization motivate the search for new diagnostics to distinguish the Galactic foreground contribution to B modes from the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Marc Kamionkowski , Ely D. Kovetz

A key goal of many Cosmic Microwave Background experiments is the detection of gravitational waves, through their B-mode polarization signal at large scales. To extract such a signal requires modelling contamination from the Galaxy. Using…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Charmaine Armitage-Caplan , Joanna Dunkley , Hans Kristian Eriksen , Clive Dickinson

One of the key science goals for the most sensitive telescopes, both current and upcoming, is the detection of the redshifted 21-cm signal from the Cosmic Dawn and Epoch of Reionization. The success of detection relies on accurate…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Aishrila Mazumder , Arnab Chakraborty , Abhirup Datta , Samir Choudhuri , Nirupam Roy , Yogesh Wadadekar , C. H. Ishwara-Chandra

This paper discusses the Cosmic Background (CB) dipoles observations in the framework of the Planck mission. Dipoles observations can be used in three ways: (i) It gives a measurement of the peculiar velocity of our Galaxy which is an…

Astrophysics · Physics 2009-11-07 M. Piat , G. Lagache , J. P. Bernard , M. Giard , J. L. Puget

In 2018 the EDGES experiment claimed the first detection of the global cosmic 21cm signal, which featured an absorption trough centered around $z \sim 17$ with a depth of approximately -500mK. This amplitude is deeper than the standard…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-11 Junsong Cang , Andrei Mesinger , Steven G. Murray , Daniela Breitman , Yuxiang Qin , Roberto Trotta