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Related papers: Inference from the 21cm signal

200 papers

State-of-the-art simulations of reionisation-era 21-cm signal have limited volumes, generally orders of magnitude smaller than observations. Consequently, the Fourier modes in common between simulation and observation have limited overlap,…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-19 Daniela Breitman , Andrei Mesinger , Steven G. Murray , Anshuman Acharya

In the coming decade, low-frequency radio arrays will begin to probe the epoch of reionization via the redshifted 21-cm hydrogen line. Successful interpretation of these observations will require effective statistical techniques for…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Vera Gluscevic , Rennan Barkana

The dark ages 21-cm signal is a promising probe of the currently unobserved infant universe between the formation of the Cosmic Microwave Background around $z \approx 1100$ and the first galaxies around $z\approx 30$. A detection of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-25 H. T. J. Bevins

The 21-cm hyperfine line of neutral hydrogen is a useful tool to probe the conditions of the Universe during the Dark Ages, Cosmic Dawn, and the Epoch of Reionisation. In most of the current calculations, the 21-cm line signals at given…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-23 Jennifer Y. H. Chan , Qin Han , Kinwah Wu , Jason D. McEwen

Motivated by recent progress in studies of the high-$z$ Universe, we build a new model for the global 21-cm signal that is explicitly calibrated to measurements of the galaxy luminosity function (LF) and further tuned to match the Thomson…

Astrophysics of Galaxies · Physics 2016-12-06 Jordan Mirocha , Steven R. Furlanetto , G. Sun

The precise form of the foregrounds for sky-averaged measurements of the 21-cm line during and before the epoch of reionization is unknown. We suggest that the level of complexity in the foreground models used to fit global 21-cm data…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-26 Geraint Harker

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

The distribution of matter fluctuations in our universe is key for understanding the nature of dark matter and the physics of the early cosmos. Different observables have been able to map this distribution at large scales, corresponding to…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-01 Julian B. Muñoz , Cora Dvorkin , Francis-Yan Cyr-Racine

The 21-cm signal from neutral hydrogen in the early universe will provide unprecedented information about the first stars and galaxies. Extracting this information, however, requires accounting for many unknown astrophysical processes.…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-21 Charlotte A. Mason , Julian B. Muñoz , Bradley Greig , Andrei Mesinger , Jaehong Park

Observational astronomy is plagued with selection effects that must be taken into account when interpreting data from astronomical surveys. Because of the physical limitations of observing time and instrument sensitivity, datasets are…

History and Philosophy of Physics · Physics 2023-02-22 Sarah C. Gallagher , Chris Smeenk

The redshifted 21-cm monopole is expected to be a powerful probe of the epoch of the first stars and galaxies ($10<z<35$). The global 21-cm signal is sensitive to the thermal and ionization state of hydrogen gas and thus provides a tracer…

Cosmology with large interferometric telescopes is a rich and largely unexplored subject, involving three types of measurement: astrometric measurement of absolute distances and proper motions, dispersions of relative proper motions, and…

Astrophysics · Physics 2007-05-23 David Tytler

Efforts are underway to measure the global 21 cm signal from neutral hydrogen, which is a powerful probe of the early universe, using NASA radio telescopes on the far side of the Moon. Physics-based models of the signal are computationally…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 J. Dorigo Jones , J. O. Burns , D. Rapetti , Shah Mohammad Bahauddin , B. Reyes , D. W. Barker

The peculiar velocity of the intergalactic gas responsible for the cosmic 21cm background from the epoch of reionization and beyond introduces an anisotropy in the three-dimensional power spectrum of brightness temperature fluctuations.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Yi Mao , Paul R. Shapiro , Garrelt Mellema , Ilian T. Iliev , Jun Koda , Kyungjin Ahn

The cosmological 21cm signal is a physics-rich probe of the early Universe, encoding information about both the ionization and the thermal history of the intergalactic medium (IGM). The latter is likely governed by X-rays from…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-17 Fabio Pacucci , Andrei Mesinger , Stefano Mineo , Andrea Ferrara

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

The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the last. In this work we present a fully-Bayesian method,…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-27 G. Bernardi , J. T. L. Zwart , D. Price , L. J. Greenhill , A. Mesinger , J. Dowell , T. Eftekhari , S. W. Ellingson , J. Kocz , F. Schinzel

It is predicted that the spectrum of radio emission from the whole sky should show a dip arising from the action of the light from the first stars on the hydrogen atoms in the surrounding gas, which causes the 21-cm line to appear in…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-27 Richard Hills , Girish Kulkarni , P. Daniel Meerburg , Ewald Puchwein

Line-Intensity Mapping is an emerging technique which promises new insights into the evolution of the Universe, from star formation at low redshifts to the epoch of reionization and cosmic dawn. It measures the integrated emission of atomic…

Observations of the 21-cm signal are opening a window to the cosmic-dawn epoch, when the first stars formed. These observations are usually interpreted with semi-numerical or hydrodynamical simulations, which are often computationally…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Hector Afonso G. Cruz , Julian B. Munoz , Nashwan Sabti , Marc Kamionkowski