Adélie Gorce
A5039957125- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Statistical and numerical algorithms
- Antenna Design and Optimization
- Superconducting and THz Device Technology
- Gyrotron and Vacuum Electronics Research
- Radio Wave Propagation Studies
- Spatial and Panel Data Analysis
- Astronomy and Astrophysical Research
- Pulsars and Gravitational Waves Research
- Pulsed Power Technology Applications
- Microwave Engineering and Waveguides
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Advanced Statistical Methods and Models
- Astronomical Observations and Instrumentation
- Particle accelerators and beam dynamics
- Scientific Research and Discoveries
- GNSS positioning and interference
- Stellar, planetary, and galactic studies
- Photonic and Optical Devices
- Climate variability and models
- Advanced Research in Science and Engineering
Institut d'Astrophysique Spatiale
2018-2025
Université Paris-Saclay
2019-2025
Centre National de la Recherche Scientifique
2018-2025
McGill University
2021-2024
University of California, Berkeley
2024
Imperial College London
2018-2022
Université Paris-Sud
2018-2019
Abstract We report the most sensitive upper limits to date on 21 cm epoch of reionization power spectrum using 94 nights observing with Phase I Hydrogen Epoch Reionization Array (HERA). Using similar analysis techniques as in previously reported limits, we find at 95% confidence that Δ 2 ( k = 0.34 h Mpc −1 ) ≤ 457 mK z 7.9 and 0.36 3496 10.4, an improvement by a factor 2.1 2.6, respectively. These are mostly consistent thermal noise over wide range after our data quality cuts, despite...
Abstract This paper presents the design and deployment of Hydrogen Epoch Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements Reionization. First results from I array are published early 2022, system nearing completion. We describe discuss progress on commissioning future upgrades. As designated Square Kilometre pathfinder instrument, we also show number “case studies” that investigate systematics seen while system, which...
Recent results of ground-based telescopes, giving high-quality measurements the cosmic microwave background (CMB) temperature power spectrum on small scales (below 1 deg) motivate need for an accurate model foregrounds, which dominate primary signal at these multipoles. In a previous work, we have shown that cosmological information could be retrieved from thermal Sunyaev Zel’dovich (SZ) effect. this introduce physically motivated Epoch Reionisation in analysis CMB data, is coherent all...
Abstract The precise characterization and mitigation of systematic effects is one the biggest roadblocks impeding detection fluctuations cosmological 21 cm signals. Missing data in radio experiments, often due to frequency interference (RFI), pose a particular challenge power spectrum analysis as this could lead ringing bright foreground modes Fourier space, heavily contaminating Here we show that problem missing becomes even more arduous presence effects. Using realistic numerical...
ABSTRACT Detection of the faint 21 cm line emission from Cosmic Dawn and Epoch Reionization will require not only exquisite control over instrumental calibration systematics to achieve necessary dynamic range observations but also validation analysis techniques demonstrate their statistical properties signal loss characteristics. A key ingredient in achieving this is ability perform high-fidelity simulations kinds data that are produced by large, many-element, radio interferometric arrays...
Abstract The cross-correlation between the 21 cm field and galaxy distribution is a potential probe of Epoch Reionization (EoR). signal traces neutral gas in intergalactic medium and, on large spatial scales, this should be anticorrelated with high-redshift distribution, which partly sources tracks ionized gas. In near future, interferometers such as Hydrogen Array (HERA) are projected to provide extremely sensitive measurements power spectrum. At same time, Nancy Grace Roman Space Telescope...
ABSTRACT During the Epoch of Reionization (EoR), ultraviolet radiation from first stars and galaxies ionized neutral hydrogen intergalactic medium, which can emit through its 21 cm hyperfine transition. Measuring power spectrum is a key science goal for future Square Kilometre Array (SKA); however, observing interpreting it challenging task. Another high-potential probe EoR patchy kinetic Sunyaev–Zel’dovich (pkSZ) effect, observed as foreground to cosmic microwave background temperature...
Interferometric experiments designed to detect the highly redshifted 21-cm signal from neutral hydrogen are producing increasingly stringent constraints on power spectrum, but some k-modes remain systematics-dominated. Mutual coupling is a major systematic that must be overcome in order signal, and simulations reproduce effects seen data can guide strategies for mitigating mutual coupling. In this paper, we analyse 12 nights of Hydrogen Epoch Reionization Array compare against include...
The 21 cm transition from neutral Hydrogen promises to be the best observational probe of Epoch Reionisation (EoR). This has led construction low-frequency radio interferometric arrays, such as Reionization Array (HERA), aimed at systematically mapping this emission for first time. Precision calibration, however, is a requirement in observations. Due spatial compactness HERA, array prone effects mutual coupling, which inevitably lead non-smooth calibration errors that contaminate data. When...
We present a new statistical tool, called the triangle correlation function (TCF), inspired by earlier work of Obreschkow et al. It is derived from three-point and aims to probe characteristic scale ionized regions during epoch reionization 21cm interferometric observations. Unlike most works, which focus on power spectrum, i.e. amplitude information, our statistic based information we can extract phases Fourier transform ionization field. In this perspective, it may benefit well-known...
Combining the visibilities measured by an interferometer to form a cosmological power spectrum is complicated process. In delay-based analysis, mapping between instrumental and space not one-to-one relation. Instead, neighbouring modes contribute at one point, with their respective contributions encoded in window functions. To better understand interferometer, we assess impact of instrument characteristics analysis choices on these Focusing Hydrogen Epoch Reionization Array (HERA) as case...
We show that, in the context of patchy reionisation, an accurate description angular power spectrum kinetic Sunyaev-Zel'dovich (kSZ) effect is not possible with simple scaling relations between amplitude and global parameters, such as reionisation midpoint its duration. introduce a new parameterisation this spectrum, based on novel free electrons density contrast Pee (k,z) terms history morphology. directly relate features to typical ionised bubble size at different stages process and,...
Photometric galaxy surveys probe the late-time Universe where density field is highly non-Gaussian. A consequence emergence of super-sample covariance (SSC), a non-Gaussian term that sensitive to fluctuations on scales larger than survey window. In this work, we study impact geometry SSC and, subsequently, cosmological parameter inference. We devise fast approximation accounts for and compare its performance common rescaling results by fraction sky covered survey, $f_\mathrm{SKY}$, dubbed...
Recent measurements from the CMB and high-redshift galaxy observations have placed rough constraints on midpoint duration of Epoch Reionization. Detailed ionization history remain elusive, although two proposed probes show great promise for this purpose: 21cm global signal kinetic Sunyaev-Zel'dovich (kSZ) effect. We formally confirm common assumption that these are highly complementary, with kSZ being more sensitive to extended histories rapidly evolving ones. do so by performing a...
We discuss constraints on cosmic reionisation and their implications a SFR density $\rho_\mathrm{SFR}$ model; we study the influence of key-parameters such as clumping factor ionised hydrogen in intergalactic medium (IGM) $C_{H_{II}}$ fraction ionising photons escaping star-forming galaxies to reionise IGM $f_\mathrm{esc}$. Our analysis uses history data coming from luminosity functions, assuming that were sufficient lead process at high redshift. add two other sets constraints: measurements...
This paper presents the design and deployment of Hydrogen Epoch Reionization Array (HERA) phase II system. HERA is designed as a staged experiment targeting 21 cm emission measurements Reionization. First results from I array are published early 2022, system nearing completion. We describe discuss progress on commissioning future upgrades. As designated Square Kilometer (SKA) pathfinder instrument, we also show number "case studies" that investigate systematics seen while system, which may...
Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different timescales. These can be isolated by designing appropriate Fourier filters in fringe-rate (FR) space, pair local sidereal time (LST). Applications FR filtering include separating correlated with rotating sky vs. those relative ground, down-weighting emission primary beam sidelobes, and suppressing noise. causes noise...
The small-scale CMB angular power spectrum contains many contaminants from secondary anisotropies created by large-scale structures. Although their contribution is taken into account in the analyses, cosmological dependence often ignored. We propose a new analysis of SPT data focusing on contributions Sunyaev Zel’dovich effects (tSZ and kSZ). After modelling these two building emulator, we show that using information tSZ kSZ addition to primordial contained provides comparable constraints...
Deviations from Gaussianity in the distribution of fields probed by large-scale structure surveys generate additional terms data covariance matrix, increasing uncertainties measurement cosmological parameters. Super-sample (SSC) is among largest these non-Gaussian contributions, with potential to significantly degrade constraints on some parameters model under study -- especially for weak-lensing cosmic shear. We compute and validate impact SSC forecast photometric survey, investigate how...
ABSTRACT Radio interferometers targeting the 21cm brightness temperature fluctuations at high redshift are subject to systematic effects that operate over a range of different time-scales. These can be isolated by designing appropriate Fourier filters in fringe-rate (FR) space, pair local sidereal time. Applications FR filtering include separating correlated with rotating sky versus those relative ground, down-weighting emission primary beam sidelobes, and suppressing noise. causes noise...
Super-sample covariance (SSC) is an important effect for cosmological analyses that use the deep structure of cosmic web; it may, however, be nontrivial to include practically in a pipeline. We solve this difficulty by presenting formula precision (inverse covariance) matrix and show applications update likelihood or Fisher forecast pipelines. The has several advantages terms speed, reliability, stability, ease implementation. present analytical application formal equivalence between three...
We report the most sensitive upper limits to date on 21 cm epoch of reionization power spectrum using 94 nights observing with Phase I Hydrogen Epoch Reionization Array (HERA). Using similar analysis techniques as in previously reported (HERA Collaboration 2022a), we find at 95% confidence that $\Delta^2(k = 0.34$ $h$ Mpc$^{-1}$) $\leq 457$ mK$^2$ $z 7.9$ and $\Delta^2 (k 0.36$ Mpc$^{-1}) \leq 3,496$ 10.4$, an improvement by a factor 2.1 2.6 respectively. These are mostly consistent thermal...
ABSTRACT The patchy kinetic Sunyaev–Zel’dovich (kSZ) signal is an integral probe of the timing and morphology epoch reionization (EoR). Recent observations have claimed a low signal-to-noise (S/N) measurement, with dramatic increase in S/N expected near future. In this work, we quantify what can learn about EoR from kSZ signal. We perform Bayesian inference by sampling galaxy properties using forward-models as well other likelihood. Including recent measurement obtained South Pole Telescope...
Intensity mapping of the 21cm signal neutral hydrogen will yield exciting insights into Epoch Reionisation and nature first galaxies. However, large amount data that be generated by next generation radio telescopes, such as Square Kilometre Array (SKA), well numerous observational obstacles to overcome, require analysis techniques tuned extract reionisation history morphology. In this context, we introduce a one-point statistic, which refer local variance, $\sigma_\mathrm{loc}$, describes...
Detection of the faint 21 cm line emission from Cosmic Dawn and Epoch Reionisation will require not only exquisite control over instrumental calibration systematics to achieve necessary dynamic range observations but also validation analysis techniques demonstrate their statistical properties signal loss characteristics. A key ingredient in achieving this is ability perform high-fidelity simulations kinds data that are produced by large, many-element, radio interferometric arrays have been...