Paul La Plante
A5047206431- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Radio Wave Propagation Studies
- Antenna Design and Optimization
- Superconducting and THz Device Technology
- Soil Moisture and Remote Sensing
- Cosmology and Gravitation Theories
- Electromagnetic Compatibility and Measurements
- History and Developments in Astronomy
- Millimeter-Wave Propagation and Modeling
- Particle Accelerators and Free-Electron Lasers
- Computational Physics and Python Applications
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Quantum, superfluid, helium dynamics
- Gyrotron and Vacuum Electronics Research
- Advanced Wireless Communication Techniques
- Pulsed Power Technology Applications
- Optical measurement and interference techniques
- demographic modeling and climate adaptation
- Superconducting Materials and Applications
- Gamma-ray bursts and supernovae
- Statistical Methods and Inference
University of Pennsylvania
2017-2025
University of California, Berkeley
2020-2025
University of Nevada, Las Vegas
2023-2025
Massachusetts Institute of Technology
2023
University of Manchester
2023
Philadelphia University
2021
Carnegie Mellon University
2014-2018
Loyola University Maryland
2012
Abstract We report upper limits on the Epoch of Reionization 21 cm power spectrum at redshifts 7.9 and 10.4 with 18 nights data (∼36 hr integration) from Phase I Hydrogen Array (HERA). The show evidence for systematics that can be largely suppressed systematic models down to a dynamic range ∼10 9 respect peak foreground power. This yields 95% confidence limit <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi...
Abstract Recently, the Hydrogen Epoch of Reionization Array (HERA) has produced experiment’s first upper limits on power spectrum 21 cm fluctuations at z ∼ 8 and 10. Here, we use several independent theoretical models to infer constraints intergalactic medium (IGM) galaxies during epoch reionization from these limits. We find that IGM must have been heated above adiabatic-cooling threshold by 8, uncertainties about ionization radio background. Combining HERA with complementary observations...
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...
We present a study of internal reflection and cross coupling systematics in Phase I the Hydrogen Epoch Reionization Array (HERA). In companion paper, we outlined mathematical formalism for such presented algorithms modeling removing them from data. this work, apply these techniques to data HERA's first observing season as method demonstration. The show evidence that, without removal, would hinder detection 21 cm power spectrum targeted EoR line-of-sight modes range 0.2 < k_parallel 0.5\ h^-1...
We present a highly parallel implementation of the cross-correlation time-series data using graphics processing units (GPUs), which is scalable to hundreds independent inputs and suitable for signals from ‘large-[Formula: see text]’ arrays many radio antennas. The computational part algorithm, X-engine, implemented efficiently on NVIDIA’s Fermi architecture, sustaining up 79% peak single-precision floating-point throughput. compare performance obtained hardware- software-managed caches,...
Active Galactic Nuclei (AGN) and star-forming galaxies are leading candidates for being the luminous sources that reionized our Universe. Next-generation 21cm surveys promising to break degeneracies between a broad range of reionization models, hence revealing nature source population. While many current efforts focused on measurement power spectrum, some will also image field during reionization. This provides further information with which determine reionizing sources. We create...
ABSTRACT In 21-cm cosmology, precision calibration is key to the separation of neutral hydrogen signal from very bright but spectrally smooth astrophysical foregrounds. The Hydrogen Epoch Reionization Array (HERA), an interferometer specialized for cosmology and now under construction in South Africa, was designed be largely calibrated using self-consistency repeated measurements same interferometric modes. This technique, known as redundant-baseline resolves most internal degrees freedom...
Abstract We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch Reionization Array (HERA), which aims to measure cosmological 21 cm signal from Reionization. HERA is a drift-scan array with 10° wide field view, meaning bright, well-characterized point-source transits are scarce. This, combined HERA’s redundant sampling uv plane and modest angular resolution instrument, make traditional sky-based self-calibration techniques difficult implement high dynamic range....
Radio Frequency Interference (RFI) is an ever-present limiting factor among radio telescopes even in the most remote observing locations. When looking to retain maximum amount of sensitivity and reduce contamination for Epoch Reionization studies, identification removal RFI especially important. In addition improved identification, we must also take into account computational efficiency RFI-Identification algorithm as interferometer arrays such Hydrogen Array grow larger number receivers. To...
In recent years, machine learning (ML) methods have remarkably improved how cosmologists can interpret data. The next decade will bring new opportunities for data-driven cosmological discovery, but also present challenges adopting ML methodologies and understanding the results. could transform our field, this transformation require astronomy community to both foster promote interdisciplinary research endeavors.
ABSTRACT The detection of the Epoch Reionization (EoR) delay power spectrum using a ‘foreground avoidance method’ highly depends on instrument chromaticity. systematic effects induced by radio telescope spread foreground signal in domain, which contaminates EoR window theoretically observable. Applied to Hydrogen Array (HERA), this paper combines detailed electromagnetic and electrical simulations order model chromatic instrument, quantify its frequency time responses. In particular,...
We describe the validation of HERA Phase I software pipeline by a series modular tests, building up to an end-to-end simulation. The philosophy this approach is validate and algorithms used in upper limit analysis on wholly synthetic data satisfying assumptions that analysis, not addressing whether actual meet these assumptions. discuss organization approach, specific tests performed, construction simulations. explicitly limitations scope current simulation effort. With mock visibility...
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...
We present predictions for the 21 cm brightness temperature power spectrum during Epoch of Reionization (EoR). discuss implications "light cone" effect, which incorporates evolution neutral hydrogen fraction and along line sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model density field signal in large volumes (L = 2 Gpc h−1). The inclusion light cone effect leads to relative decrease about 50% on all scales. also find that is more prominent at...
We introduce DAYENU, a linear, spectral filter for HI intensity mapping that achieves the desirable foreground mitigation and error minimization properties of inverse co-variance weighting with minimal modeling underlying data. Beyond 21 cm power-spectrum estimation, our is suitable any analysis where high dynamic-range removal spectrally smooth foregrounds in irregularly (or regularly) sampled data required, something required by many other techniques. Our filtering matrix diagonalized...
We have run a new suite of simulations that solve hydrodynamics and radiative transfer simultaneously to study helium II reionization. Our employs various models for populating quasars inside dark matter halos, which affect the He reionization history. In particular, we are able explore impact differences in timing duration on observables. examine thermal signature leaves IGM, measure temperature-density relation. As previous studies shown, confirm photoheating feedback from raises...
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 Upcoming galaxy surveys and 21-cm experiments targeting high redshifts z ≳ 6 are highly complementary probes of formation reionization. However, in order to expedite the large-volume simulations relevant for observations, many models galaxies within reionization codes entirely subgrid and/or rely on halo abundances only. In this work, we explore extent which resolving modelling individual histories affects predictions both populations detectable by upcoming signatures accessible...
Radio Frequency Interference (RFI) is one of the systematic challenges preventing 21cm interferometric instruments from detecting Epoch Reionization. To mitigate effects RFI on data analysis pipelines, numerous inpaint techniques have been developed to restore corrupted data. We examine qualitative and quantitative errors introduced into visibilities power spectrum due inpainting. perform our simulated as well real Hydrogen Reionization Array (HERA) Phase 1 upper limits. also introduce a...
Characterizing the epoch of reionization (EoR) at z≳6 via redshifted 21 cm line neutral Hydrogen (H i) is critical to modern astrophysics and cosmology, thus a key science goal many current planned low-frequency radio telescopes. The primary challenge detecting this signal overwhelmingly bright foreground emission these frequencies, placing stringent requirements on knowledge instruments inaccuracies in analyses. Results from experiments have largely been limited not by thermal sensitivity...
The high-redshift 21 cm signal from the Epoch of Reionization (EoR) is a promising observational probe early universe. Current- and next-generation radio interferometers such as Hydrogen Array (HERA) Square Kilometre (SKA) are projected to measure auto power spectrum EoR. Another this era kinetic Sunyaev-Zel'dovich (kSZ) in cosmic microwave background (CMB), which will be observed by upcoming Simons Observatory (SO) CMB-S4 experiments. contribution kSZ EoR expected anti-correlated, former...
Reionization of helium is expected to occur at redshifts $z\sim3$ and have important consequences for quasar populations, galaxy formation, the morphology intergalactic medium, but there little known empirically about process. Here we show that kinetic Sunyaev-Zeldovich (kSZ) tomography, based on combination CMB measurements surveys, can be used infer primordial abundance as well time duration reionization. We find a high-significance detection ${\sim10\sigma}$ from Vera Rubin Observatory...
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...