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The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation (EoR). This has led to the construction of low-frequency radio interferometric arrays, such as the Hydrogen Epoch of…

Detecting cosmological signals from the Epoch of Reionization (EoR) requires high-precision calibration to isolate the cosmological signals from foreground emission. In radio interferometery, perturbed primary beams of antenna elements can…

I present our analysis of the 21cm power spectrum upper limits from the HERA radio interferometer, published in HERA Collaboration et al. 2022. We use the recent limits to constrain reionization and the properties of the IGM and galaxies in…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-25 Stefan Heimersheim

We present a new upper limit to the 21cm power spectrum during the Epoch of Reionization (EoR) which constrains reionization models with an unheated IGM. The GMRT-EoR experiment is an ongoing effort to make a statistical detection of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Gregory Paciga , Tzu-Ching Chang , Yashwant Gupta , Rajaram Nityanada , Julia Odegova , Ue-Li Pen , Jeffrey Peterson , Jayanta Roy , Kris Sigurdson

We present an analysis of Epoch of Reionization data from Phase II of the Murchison Widefield Array using the \texttt{simpleDS} delay spectrum pipeline. Prior work analyzed the same observations using the FHD/$\varepsilon$ppsilon imaging…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Matthew Kolopanis , Jonathan Pober , Daniel C. Jacobs , Samantha McGraw

Current attempts to measure the 21cm Power Spectrum of neutral hydrogen during the Epoch of Reionization are limited by systematics which produce measured upper limits above both the thermal noise and the expected cosmological signal. These…

We use the Fisher matrix formalism and semi-numerical simulations to derive quantitative predictions of the constraints that power spectrum measurements on next-generation interferometers, such as the Hydrogen Epoch of Reionization Array…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-26 Aaron Ewall-Wice , Jacqueline Hewitt , Andrei Mesinger , Joshua S. Dillon , Adrian Liu , Jonathan Pober

Measurement of fluctuations in diffuse HI 21 cm background radiation from the post-reionization epoch (z < 6) is a promising avenue to probe the large-scale structure of the Universe and understand the evolution of galaxies. We observe the…

We present new constraints on the 21cm Epoch of Reionization (EoR) power spectrum derived from 3 months of observing with a 32-antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of…

Characterizing the epoch of reionization (EoR) at $z\gtrsim 6$ via the redshifted 21 cm line of neutral Hydrogen (HI) is critical to modern astrophysics and cosmology, and thus a key science goal of many current and planned low-frequency…

The Epoch of Reionization (EoR) is an uncharted era in our Universe's history during which the birth of the first stars and galaxies led to the ionization of neutral hydrogen in the intergalactic medium. There are many experiments…

Unaccounted for systematics from foregrounds and instruments can severely limit the sensitivity of current experiments from detecting redshifted 21~cm signals from the Epoch of Reionization (EoR). Upcoming experiments are faced with a…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-06 Nithyanandan Thyagarajan , Aaron Parsons , David DeBoer , Judd Bowman , Aaron Ewall-Wice , Abraham Neben , Nipanjana Patra

The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer aiming to detect the power spectrum of 21 cm fluctuations from neutral hydrogen from the Epoch of Reionization (EOR). Drawing on lessons from the Murchison Widefield…

In this paper, we report new limits on 21cm emission from cosmic reionization based on a 135-day observing campaign with a 64-element deployment of the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) in South…

Precise measurements of the 21 cm power spectrum are crucial for understanding the physical processes of hydrogen reionization. Currently, this probe is being pursued by low-frequency radio interferometer arrays. As these experiments come…

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

The fluctuations in the dark matter-baryon relative velocity field are imprinted as acoustic oscillations in the 21-cm power spectrum during cosmic dawn (CD). These velocity acoustic oscillations (VAOs) keep the imprints of the comoving…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-08 Debanjan Sarkar , Ely D. Kovetz

The detection of redshifted hyperfine line of neutral hydrogen (HI) is the most promising probe of the Epoch of Reionization (EoR). We report an analysis of 55 hours of Murchison Widefield Array (MWA) Phase II drift scan EoR data. The data…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Akash Kumar Patwa , Shiv Sethi , K. S. Dwarakanath

This paper presents the spherically-averaged 21 cm power spectrum derived from Epoch of Reionization (EoR) observations conducted with the Murchison Widefield Array (MWA). The analysis uses EoR0-field data, centered at (RA$=0h$,…