English
Related papers

Related papers: Detecting Early Galaxies Through Their 21-cm Signa…

200 papers

A primeval galaxy represents the earliest stages of a galaxy's life and as such provides clues to the early history of the Universe and the evolution of stars and galaxies. Over the last 20 years astronomers have been engaged in the quest…

Astrophysics · Physics 2009-10-31 C. A. Collins

It is widely agreed that studying the 21 cm emission line from neutral hydrogen may be our best hope for understanding the creation of the first structures during the dark ages and the Epoch of Reionization (EoR). This hyperfine transition…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-03 Mahta Moazzenzadeh , Javad T. Firouzjaee

In the current era of JWST, we continue to uncover a wealth of information about the Universe deep into the Epoch of Reionization. In this work, we use a suite of simulations with 21cmSPACE, to explore the astrophysical properties of early…

At redshifts z >~ 30 neutral hydrogen gas absorbs CMB radiation at the 21cm spin-flip frequency. In principle this is observable and a high-precision probe of cosmology. We calculate the linear-theory angular power spectrum of this signal…

Astrophysics · Physics 2008-11-26 Antony Lewis , Anthony Challinor

The first billion years of cosmic history remains largely unobserved. We demonstrate, using a novel machine learning technique, how combining upper limits on the spatial fluctuations in the 21-cm signal with observations of the sky-averaged…

The correlation between 21cm fluctuations and galaxies is sensitive to the astrophysical properties of the galaxies that drove reionization. Thus, detailed measurements of the cross-power spectrum and its evolution could provide a powerful…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jaehong Park , Han-Seek Kim , J. Stuart B. Wyithe , C. G. Lacey

We use cosmological simulations of reionization to predict the possible signal from the redshifted 21 cm line of neutral hydrogen in the pre-reionization era and to investigate the observability of this signal. We show that the separation…

Astrophysics · Physics 2009-11-10 Nickolay Y. Gnedin , Peter A. Shaver

The 21cm line of neutral hydrogen is a powerful probe of the high-redshift universe (Cosmic Dawn and the Epoch of Reionization), with an unprecedented potential to inform us about key processes of early galaxy formation, the first stars and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-05 Steven G. Murray , Jonathan Pober , Matthew Kolopanis

Spatial variations in the Lyman-$\alpha$ forest opacity at $z<6$ seem to require a late end to cosmic reionization. In this picture, the universe contains neutral hydrogen 'islands' of up to 100 cMpc$/h$ in extent down to redshifts as low…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-06 Janakee Raste , Girish Kulkarni , Catherine A. Watkinson , Laura C. Keating , Martin G. Haehnelt

Observations of the Epoch of Reionization (EoR) have the potential to answer long-standing questions of astrophysical interest regarding the nature of the first luminous sources and their effects on the intergalactic medium (IGM). We…

There is a hope that looking into the early Universe with next-generation telescopes, one will be able to observe the early accretion growth of supermassive black holes (BHs) when their masses were $\sim 10^4$-$10^6 M_\odot$. According to…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Sergey Sazonov , Ildar Khabibullin

21-cm emission from neutral hydrogen during and before the epoch of cosmic reionisation is gravitationally lensed by material at all lower redshifts. Low-frequency radio observations of this emission can be used to reconstruct the projected…

Astrophysics · Physics 2009-06-25 Stefan Hilbert , R. Benton Metcalf , S. D. M. White

The absorption features in spectra of high-redshift background radio sources, caused by hyperfine structure lines of hydrogen atoms in the intervening structures, are known collectively as the 21-cm forest. They provide a unique probe of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-21 Yue Shao , Yidong Xu , Yougang Wang , Wenxiu Yang , Ran Li , Xin Zhang , Xuelei Chen

Measurements from the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission 2 (ARCADE-2) reveal a strong radio background in the GHz frequency range. Since the cosmological 21-cm signal is measured relative to the background…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-17 Sudipta Sikder , Rajesh Mondal , Rennan Barkana , Anastasia Fialkov

Understanding the astrophysical nature of the first stars remains an unsolved problem in cosmology. The redshifted global 21-cm signal $({T}_{21})$ acts as a treasure trove to probe the cosmic dawn era -- when the intergalactic medium was…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-16 Vivekanand Mohapatra , Johnny J , Pravin Kumar Natwariya , Jishnu Goswami , Alekha C. Nayak

The 21cm neutral hydrogen line is likely to be a key probe for studying the epoch of reionization and comic dawn in the forthcoming decades. This prospect stimulates the development of the theoretical basis for simulating the power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-14 Alexander A. Kaurov

The 21-cm global signal, a treasure trove of information about the nature of the first luminous sources of the Universe, has traditionally been modelled assuming that these early sources were predominantly star-forming galaxies. However,…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-16 Atrideb Chatterjee

In this short review I present the status of the global 21-cm signal detected by EDGES in March 2018. It is organized in three parts. First, I present the EDGES experiment and the fitting procedure used by the collaboration to extract the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-16 Paolo Panci

One of the last unexplored windows to the cosmos, the Dark Ages and Cosmic Dawn, can be opened using a simple low frequency radio telescope from the stable, quiet lunar farside to measure the Global 21-cm spectrum. This frontier remains an…