Unveiling the Halo-Galaxy Connection from Cosmic Dawn to Today
ORAL
Abstract
In the next few years, observations of the 21-cm signal will open a window to the cosmic dawn epoch when the first stars formed. At the same time, ground- and space-based galaxy surveys will extend to ever higher redshifts reaching the beginning of the epoch of reionization. When combined, these measurements are poised to reveal how dark matter haloes foster the formation and evolution of their constituent galaxies across multiple epochs of cosmic time.
21-cm observations are usually interpreted with semi-numerical or hydrodynamical simulations, which are often computationally intensive and inflexible to changes in cosmological or astrophysical effects. I will present a new approach to predict the 21-cm signal in the presence of Pop III stars in seconds. Pop III stars, residing in low-mass molecular-cooling halos, are highly sensitive to feedback, especially from H2-dissociating Lyman-Werner radiation and dark matter-baryon relative velocities. I will show an effective prescription of the star formation rate density in the presence of Pop III stars that recovers the full nonlinear distributions of radiative fields that determine the 21-cm signal — including inhomogeneous feedback. I will show how PopIII stars impact the 21-cm global signal and power spectrum across cosmic time and at different distance scales. I will also highlight how the spatial modulation of the relative velocities induces Velocity Acoustic Oscillations in 21-cm power spectra, providing us with a new and robust cosmological standard ruler. Our public code, Zeus21, can predict 21-cm observables in seconds, presenting a meaningful first step towards rapid precision astrophysics and cosmology in the first billion years.
The nature of galaxy clustering at high redshifts will yield insight into the sources that drive reionization. I will present new clustering measurements of Lyman-Break Galaxies from the Subaru Hyper Suprime-Cam (HSC) at redshifts 4 < z < 6, deriving a more precise measurement of the halo-galaxy connection at high z. We perform a joint analysis with UV luminosity functions, and show how clustering measurements can break degeneracies between mean galaxy luminosity and stochasticity to explain the enhanced abundance of UV-bright galaxies observed by JWST.
21-cm observations are usually interpreted with semi-numerical or hydrodynamical simulations, which are often computationally intensive and inflexible to changes in cosmological or astrophysical effects. I will present a new approach to predict the 21-cm signal in the presence of Pop III stars in seconds. Pop III stars, residing in low-mass molecular-cooling halos, are highly sensitive to feedback, especially from H2-dissociating Lyman-Werner radiation and dark matter-baryon relative velocities. I will show an effective prescription of the star formation rate density in the presence of Pop III stars that recovers the full nonlinear distributions of radiative fields that determine the 21-cm signal — including inhomogeneous feedback. I will show how PopIII stars impact the 21-cm global signal and power spectrum across cosmic time and at different distance scales. I will also highlight how the spatial modulation of the relative velocities induces Velocity Acoustic Oscillations in 21-cm power spectra, providing us with a new and robust cosmological standard ruler. Our public code, Zeus21, can predict 21-cm observables in seconds, presenting a meaningful first step towards rapid precision astrophysics and cosmology in the first billion years.
The nature of galaxy clustering at high redshifts will yield insight into the sources that drive reionization. I will present new clustering measurements of Lyman-Break Galaxies from the Subaru Hyper Suprime-Cam (HSC) at redshifts 4 < z < 6, deriving a more precise measurement of the halo-galaxy connection at high z. We perform a joint analysis with UV luminosity functions, and show how clustering measurements can break degeneracies between mean galaxy luminosity and stochasticity to explain the enhanced abundance of UV-bright galaxies observed by JWST.
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Publication: The First Billion Years in Seconds: An Effective Model for the 21-cm Signal with Population III Stars, found at https://arxiv.org/pdf/2407.18294<br>Upcoming: Constraining cosmic reionization with joint clustering-UV luminosity function analysis of GOLDRUSH Lyman-break galaxies at 4 < z < 6
Presenters
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Hector Afonso G Cruz
Johns Hopkins University
Authors
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Hector Afonso G Cruz
Johns Hopkins University
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Julian B Munoz
Harvard University
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Marc P Kamionkowski
Johns Hopkins University