Neil Bassett

Validating Posteriors Obtained by an Emulator When Jointly Fitting Mock Data of the Global 21 cm Signal and High-z Galaxy UV Luminosity Function

J. Dorigo Jones, David Rapetti, Jordan Mirocha, Joshua J. Hibbard et autres

Abstract Although neural-network-based emulators enable efficient parameter estimation in 21 cm cosmology, the accuracy of such constraints is poorly understood. We employ nested sampling to fit mock data of the global 21 cm signal and high-z galaxy ultraviolet luminosity function (UVLF) and …

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Fitting and Comparing Galactic Foreground Models for Unbiased 21 cm Cosmology

Joshua J. Hibbard, David Rapetti, Jack O. Burns, Nivedita Mahesh et autres

Abstract Accurate detection of the cosmological 21 cm global signal requires galactic foreground models that can remove power over 106. Although foreground and global signal models unavoidably exhibit overlap in their vector spaces inducing bias error in the extracted signal, a second …

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Validating posteriors obtained by an emulator when jointly-fitting mock data of the global 21-cm signal and high-z galaxy UV luminosity function

J. Dorigo Jones, David Rapetti, Jordan Mirocha, Joshua J. Hibbard et autres

Although neural-network-based emulators enable efficient parameter estimation in 21-cm cosmology, the accuracy of such constraints is poorly understood. We employ nested sampling to fit mock data of the global 21-cm signal and high-$z$ galaxy ultraviolet luminosity function (UVLF) and compare for the …

Fitting and Comparing Galactic Foreground Models for Unbiased 21-cm Cosmology

Joshua J. Hibbard, David Rapetti, Jack O. Burns, Nivedita Mahesh et autres

Accurate detection of the cosmological 21-cm global signal requires galactic foreground models which can remove power over ~$10^6$. Although foreground and global signal models unavoidably exhibit overlap in their vector-spaces inducing bias error in the extracted signal, a second source of bias …

Constraining a Model of the Radio Sky below 6 MHz Using the Parker Solar Probe/FIELDS Instrument in Preparation for Upcoming Lunar-based Experiments

Neil Bassett, David Rapetti, Bang D. Nhan, Brent Page et autres

Abstract We present a Bayesian analysis of data from the FIELDS instrument on board the Parker Solar Probe (PSP) spacecraft with the aim of constraining low-frequency (≲6 MHz) sky in preparation for several upcoming lunar-based experiments. We utilize data recorded during PSP’s …

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LuSEE 'Night': The Lunar Surface Electromagnetics Experiment

S. D. Bale, Neil Bassett, Jack O. Burns, Johnny Dorigo Jones et autres

The Lunar Surface Electromagnetics Explorer 'LuSEE Night' is a low frequency radio astronomy experiment that will be delivered to the farside of the Moon by the NASA Commercial Lunar Payload Services (CLPS) program in late 2025 or early 2026. The payload system …

Constraining a Model of the Radio Sky Below 6 MHz Using the Parker Solar Probe/FIELDS Instrument in Preparation for Upcoming Lunar-based Experiments

Neil Bassett, David Rapetti, Bang D. Nhan, Brent D. G. Page et autres

We present a Bayesian analysis of data from the FIELDS instrument on board the Parker Solar Probe (PSP) spacecraft with the aim of constraining low frequency ($\lesssim$ 6 MHz) sky in preparation for several upcoming lunar-based experiments. We utilize data recorded during …

The l = 2 spherical harmonic expansion coefficients of the sky brightness distribution between 0.5 and 7 MHz

Brent Page, Neil Bassett, A. Lecacheux, M. Pulupa et autres

Context. The opacity of the ionosphere prevents comprehensive Earth-based surveys of low frequency ν ≲ 10 MHz astrophysical radio emissions. The limited available data in this frequency regime show a downturn in the mean sky brightness at ν ≲ 3 MHz in …

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Constraining Warm Dark Matter and Population III Stars with the Global 21 cm Signal

Joshua J. Hibbard, Jordan Mirocha, David Rapetti, Neil Bassett et autres

Abstract Upcoming ground- and space-based experiments may have sufficient accuracy to place significant constraints upon high-redshift star formation, Reionization, and dark matter (DM) using the global 21 cm signal of the intergalactic medium. In the early universe, when the relative abundance of …

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Lost Horizon: Quantifying the Effect of Local Topography on Global 21 cm Cosmology Data Analysis

Neil Bassett, David Rapetti, Keith Tauscher, Bang D. Nhan et autres

Abstract We present an investigation of the horizon and its effect on global 21 cm observations and analysis. We find that the horizon cannot be ignored when modeling low-frequency observations. Even if the sky and antenna beam are known exactly, forward models …

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Global 21 cm Signal Extraction from Foreground and Instrumental Effects. IV. Accounting for Realistic Instrument Uncertainties and Their Overlap with Foreground and Signal Models

Keith Tauscher, David Rapetti, Bang D. Nhan, Alec Handy et autres

Abstract All 21 cm signal experiments rely on electronic receivers that affect the data via both multiplicative and additive biases through the receiver’s gain and noise temperature. While experiments attempt to remove these biases, the residuals of their imperfect calibration techniques can …

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Novel Statistical Framework for Modeling Systematics in Global 21-cm Cosmology

David Rapetti, Keith Tauscher, Neil Bassett, Joshua J. Hibbard et autres