English
Related papers

Related papers: Cosmology and Astrophysics Using the Post-reioniza…

200 papers

The epoch of reionization (EoR), marking the Universe's transition from a neutral to ionized state, represents a pivotal phase for understanding the formation of the first stars and galaxies. Intensity mapping of atomic and molecular lines,…

Astrophysics of Galaxies · Physics 2025-12-17 Anirban Roy , Anthony Pullen , Patrick C. Breysse , Rachel S. Somerville

Observations of 21-cm radio emission by neutral hydrogen at redshifts z ~ 0.5 to ~ 2.5 are expected to provide a sensitive probe of cosmic dark energy. This is particularly true around the onset of acceleration at z ~ 1, where traditional…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-22 Tzu-Ching Chang , Ue-Li Pen , Kevin Bandura , Jeffrey B. Peterson

Absorption or emission against the cosmic microwave background radiation (CMB) may be observed in the redshifted 21cm line if the spin temperature of the neutral intergalactic medium prior to reionization differs from the CMB temperature.…

Astrophysics · Physics 2009-12-10 Tiziana Di Matteo , Rosalba Perna , Tom Abel , Martin J. Rees

We use the latest results from Atacama Large Millimetre/submillimetre Array (ALMA) surveys targeting the ionized carbon [CII] 158 $\mu$m and oxygen [OIII] 88 $\mu$m lines, in combination with data-driven predictions for the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Hamsa Padmanabhan

We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution simulation of cosmic reionization. The…

Precision cosmology requires accurate galaxy redshifts, but next generation optical surveys will observe unprecedented numbers of resolved galaxies, placing strain on the amount of spectroscopic follow-up required. We show how useful…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Steven Cunnington , Ian Harrison , Alkistis Pourtsidou , David Bacon

One of the next decade's most exciting prospects is to explore the cosmic "dark ages," during which the first stars in the Universe formed, with the 21 cm line of neutral hydrogen. At z>6, this light redshifts into the low-frequency radio…

The upcoming Square Kilometre Array Low Frequency (SKA-Low) interferometer will have the required sensitivity to detect the 21 cm line from neutral hydrogen during the Epoch of Reionisation (EoR). In preparation, we investigated the…

Instrumentation and Methods for Astrophysics · Physics 2025-09-25 E. Jong , C. Trott , C. D. Nunhokee , Q. Zheng

The redshifted 21-cm line of distant neutral H atoms provides a probe of the cosmic ``dark ages'' and the epoch of reionization (``EOR'') which ended them. The radio continuum produced by this redshifted line can be seen in absorption or…

Astrophysics · Physics 2009-11-13 Paul R. Shapiro , Ilian T. Iliev , Garrelt Mellema , Ue-Li Pen , Hugh Merz

We present an overview of the theory of high-redshift star and X-ray source formation, and how they affect the 21-cm background. Primary focus is given to Lyman alpha pumping and X-ray heating mechanisms at cosmic dawn, opening a new…

Astrophysics of Galaxies · Physics 2015-01-22 Kyungjin Ahn , Andrei Mesinger , Marcelo A. Alvarez , Xuelei Chen

We investigate the prospects of measuring the cosmic magnification effect by cross-correlating neutral hydrogen intensity mapping (HI IM) maps with background optical galaxies. We forecast the signal-to-noise ratio for HI IM data from…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Amadeus Witzemann , Alkistis Pourtsidou , Mario G. Santos

We investigate what role the SKA neutral hydrogen (HI) intensity mapping (IM) sky survey observation will play in weighing neutrinos in cosmology. We use the simulated data of the baryon acoustic oscillation (BAO) measurements from the HI…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-17 Jing-Fei Zhang , Bo Wang , Xin Zhang

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

In the next few years, the 21cm line will enable direct observations of the Dark Ages, Cosmic Dawn, and Reionization, which represent previously unexplored periods in our cosmic history. With a combination of sky-averaged global signal…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 Adrian Liu , H. Cynthia Chiang , Abigail Crites , Jonathan Sievers , Renée Hložek

Improvements in current instruments and the advent of next-generation instruments will soon push observational 21 cm cosmology into a new era, with high significance measurements of both the power spectrum and the mean ("global") signal of…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-08 Adrian Liu , Aaron R. Parsons

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

Among the tools available for the study of the dark energy driving the expansion of the Universe, Baryon Acoustic Oscillations (BAO) and their effects on the matter power spectrum are particularly attractive. It was recently proposed to…

The neutral intergalactic medium in the post reionization epoch allows us to study cosmological structure formation through the observation of the redshifted 21 cm signal and the Lyman-alpha forest. We investigate the possibility of…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-31 Ashis Kumar Pal , Tapomoy Guha Sarkar

We analyse the evolution of the largest ionized region using the topological and morphological evolution of the redshifted 21-cm signal coming from the neutral hydrogen distribution during the different stages of reionization. For this…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-12 Saswata Dasgupta , Samit Kumar Pal , Satadru Bag , Sohini Dutta , Suman Majumdar , Abhirup Datta , Aadarsh Pathak , Mohd Kamran , Rajesh Mondal , Prakash Sarkar

Intensity mapping of the 21cm signal of neutral hydrogen will yield exciting insights into the Epoch of Reionisation and the nature of the first galaxies. However, the large amount of data that will be generated by the next generation of…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Adélie Gorce , Anne Hutter , Jonathan R. Pritchard