Helium Reionization Simulations. III. The Helium Lyman-$\alpha$ Forest

Abstract

In La Plante et al. (2017), we presented a new suite of hydrodynamic simulations with the aim of accurately capturing the process of helium II reionization. In this paper, we discuss the observational signatures present in the He II Ly$\alpha$ forest. We show that the effective optical depth of the volume ${\tau }_{\mathrm{eff}}$ is not sufficient for capturing the ionization state of helium II, due to the large variance inherent in sightlines. However, the He II flux PDF can be used to determine the timing of helium II reionization. The amplitude of the one-dimensional flux power spectrum can also determine the ionization state of helium II. We show that even given the currently limited number of observations ($\sim$50 sightlines), measurements of the flux PDF can yield information about helium II reionization. Further, measurements using the one-dimensional power spectrum can provide clear indications of the timing of reionization, as well as the relative bias of sources of ionizing radiation.

9 pages, 5 figures. Submitted to ApJ

References in corpus (16)

• New Constraints on the free-streaming of warm dark matter from intermediate and small scale Lyman-$\alpha$ forest data
• The first ultraviolet quasar stacked spectrum at z=2.4 from WFC3
• HeII Reionization and its Effect on the IGM
• Radiative transfer simulations of cosmic reionization I: methodology and initial results
• The Sherwood simulation suite: overview and data comparisons with the Lyman-alpha forest at redshifts 2 < z < 5
• Imprint of Inhomogeneous Hydrogen Reionization on the Temperature Distribution of the Intergalactic Medium
• The thermal history of the intergalactic medium down to redshift z=1.5: a new curvature measurement
• The End of Helium Reionization at z~2.7 Inferred from Cosmic Variance in HST/COS HeII Lyman Alpha Absorption Spectra
• The History and Morphology of Helium Reionization
• IGM Constraints from the SDSS-III/BOSS DR9 Ly-alpha Forest Flux Probability Distribution Function
• Photo-heating and the fate of hard photons during the reionisation of HeII by quasars
• Inhomogeneous Helium Reionization and the Equation of State of the Intergalactic Medium
• Helium Reionization Simulations. II. Signatures of Quasar Activity on the IGM
• The evolution of the helium-ionizing background at z ~ 2-3
• A High Yield of New Sightlines for the Study of Intergalactic Helium: Far-UV-Bright Quasars from SDSS, GALEX, and HST
• AGN-driven helium reionization and the incidence of extended HeIII regions at redshift z>3

Cited by in corpus (12)

• The ASTRID Simulation: Galaxy Formation and Reionization
• Testing extreme-axion wave dark matter using the BOSS Lyman-Alpha forest data
• Constraining the era of helium reionization using fast radio bursts
• Inhomogeneous HeII reionization in Hydrodynamic Simulations
• Effect of non-equilibrium ionization on derived physical conditions of the high-$z$ intergalactic medium
• Effects of Photoionization and Photoheating on Lyman-alpha Forest Properties from Cholla Cosmological Simulations
• Possible evidence for a large-scale enhancement in the Lyman-$\alpha$ forest power spectrum at redshift $\text{z}\ge 4$
• Using the redshift evolution of the Lyman-$\alpha$ effective opacity as a probe of dark matter models
• The impact of faint AGN discovered by JWST on reionization
• Probing helium reionization with kinetic Sunyaev Zel'dovich tomography
• Reconstructing patchy helium reionization using the cosmic microwave background and large-scale structure
• Measuring photo-ionization rate and mean free path of HeII ionizing photons at $2.5\le z\le 3.6$: Evidence for late and rapid HeII reionization Part-II