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Models of the reionization and reheating of the intergalactic medium (IGM) at redshifts $z \gtrsim 6$ continue to grow more sophisticated in anticipation of near-future 21-cm, cosmic microwave background, and galaxy survey measurements.…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-11 Jordan Mirocha , Henri Lamarre , Adrian Liu

The observation of space-time variations in fundamental constants would provide strong evidence for the existence of new light degrees of freedom in the theory of Nature. Robustly constraining such scenarios requires exploiting observations…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-17 Laura Lopez-Honorez , Olga Mena , Sergio Palomares-Ruiz , Pablo Villanueva-Domingo , Samuel J. Witte

Detection of the redshifted 21cm-line signal from neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR) is complicated by intense foregrounds such as galactic synchrotron and extragalactic radio galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-31 Kenji Kubota , Shintaro Yoshiura , Keitaro Takahashi , Kenji Hasegawa , Hidenobu Yajima , Masami Ouchi , B. Pindor , R. L. Webster

We use the latest multi-redshift ($z=6.5-8.7$) upper limits on the 21-cm signal from the Murchison Widefield Array (MWA) to explore astrophysical models which are inconsistent with the data. These upper limits are achieved using 298 h of…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-25 Bradley Greig , Cathryn M. Trott , Nichole Barry , Simon J. Mutch , Bart Pindor , Rachel L. Webster , J. Stuart B. Wyithe

A number of current and future experiments aim to detect the reionization of neutral hydrogen by the first stars and galaxies in the Universe via the redshifted 21cm line. Using the \textsc{BlueTides} simulation, we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-20 James E Davies , Rupert A. Croft , Tiziana Di-Matteo , Bradley Greig , Yu Feng , Stuart Wyithe

Interferometric arrays seeking to measure the 21 cm signal from the Epoch of Reionization must contend with overwhelmingly bright emission from foreground sources. Accurate recovery of the 21 cm signal will require precise calibration of…

Spectral features introduced by instrumental chromaticity of radio interferometers have the potential to negatively impact the ability to perform Epoch of Reionisation (EoR) and Cosmic Dawn (CD) science using the redshifted neutral hydrogen…

Instrumentation and Methods for Astrophysics · Physics 2016-05-25 Cathryn M. Trott , Randall B. Wayth

Observations of the high-redshift Universe using the 21 cm line of neutral hydrogen and complimentary emission lines from the first galaxies promise to open a new door for our understanding of the epoch of reionization. We present…

Astrophysics of Galaxies · Physics 2019-03-13 Sebastian Dumitru , Girish Kulkarni , Guilaine Lagache , Martin G. Haehnelt

Measurement of the global 21-cm signal during Cosmic Dawn (CD) and the Epoch of Reionization (EoR) is made difficult by bright foreground emission which is 2-5 orders of magnitude larger than the expected signal. Fitting for a…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-20 Michael Pagano , Peter Sims , Adrian Liu , Dominic Anstey , Will Handley , Eloy De Lera Acedo

Concerted effort is currently ongoing to open up the Epoch of Reionization (EoR) ($z\sim$15-6) for studies with IR and radio telescopes. Whereas IR detections have been made of sources (Lyman-$\alpha$ emitters, quasars and drop-outs) in…

We use numerical simulations of cosmic reionization and radiative processes related to the HI 21 cm emission line to produce synthetic radio maps as seen by next generation radio telescopes that will operate at low radio frequencies (e.g.…

Astrophysics · Physics 2009-11-11 M. Valdes , B. Ciardi , A. Ferrara , M. Johnston-Hollitt , H. Rottgering

This paper is the first in a series of papers describing the impact of antenna instrumental artefacts on the 21-cm cosmology experiments to be carried out by the low frequency instrument (SKA1-LOW) of the Square Kilometre Array telescope…

We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Reionization (EoR). HERA is a drift-scan array with a 10 degree…

We consider the evolution of the sky-averaged 21 cm background during the early phases of structure formation. Using simple analytic models, we calculate the thermal and ionization histories, assuming that stellar photons dominate the…

Astrophysics · Physics 2009-11-11 Steven Furlanetto

We present new upper limits on the 21-cm signal power spectrum from the Epoch of Reionization (EoR), at redshifts $z \approx 10.1, 9.1, \text{ and } 8.3$, based on reprocessed observations from the Low-Frequency Array (LOFAR). The analysis…

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

Cosmic baryon evolution during the Cosmic Dawn and Reionization results in redshifted 21-cm spectral distortions in the cosmic microwave background (CMB). These encode information about the nature and timing of first sources over redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-04 Mayuri Sathyanarayana Rao , Ravi Subrahmanyan , N Udaya Shankar , Jens Chluba

Interferometry of the cosmic 21-cm signal is set to revolutionize our understanding of the Epoch of Reionization (EoR), eventually providing 3D maps of the early Universe. Initial detections however will be low signal-to-noise, limited by…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 Emanuele Sobacchi , Andrei Mesinger , Bradley Greig

The redshifted 21 cm line is an emerging tool in cosmology, in principle permitting three-dimensional surveys of our Universe that reach unprecedentedly large volumes, previously inaccessible length scales, and hitherto unexplored epochs of…

Instrumentation and Methods for Astrophysics · Physics 2020-04-27 Adrian Liu , J. Richard Shaw

Our understanding of the intergalactic medium at redshifts $z=5$-$6$ has improved considerably in the last few years due to the discovery of quasars with $z>6$ that enable Lyman-$\alpha$ forest studies at these redshifts. A realisation from…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Janakee Raste , Girish Kulkarni , Laura C. Keating , Martin G. Haehnelt , Jonathan Chardin , Dominique Aubert