English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The latest measurements of CMB electron scattering optical depth reported byPlanck significantly reduces the allowed space of HI reionization models,pointing toward a later ending and/or less extended phase transition thanpreviously believed. Reionization impulsively heats the intergalactic medium(IGM) to $\sim10^4$ K, and owing to long cooling and dynamical times in thediffuse gas, comparable to the Hubble time, memory of reionization heating isretained. Therefore, a late ending reionization has significant implicationsfor the structure of the $z\sim5-6$ Lyman-$\alpha$ (ly$\alpha$) forest. Usingstate-of-the-art hydrodynamical simulations that allow us to vary the timing ofreionization and its associated heat injection, we argue that extant thermalsignatures from reionization can be detected via the Ly$\alpha$ forest powerspectrum at $5< z<6$. This arises because the small-scale cutoff in the powerdepends not only the the IGM temperature at these epochs, but is alsoparticularly sensitive to the pressure smoothing scale set by the IGM fullthermal history. Comparing our different reionization models with existingmeasurements of the Ly$\alpha$ forest flux power spectrum at $z=5.0-5.4$, wefind that models satisfying Planck's $\tau_e$, constraint favor a moderateamount of heat injection consistent with galaxies driving reionization, butdisfavoring quasar-driven scenarios. We explore the impact of differentreionization histories and heating models on the shape of the power spectrum,and find that they can produce similar effects, but argue that this degeneracycan be broken with high enough quality data. We study the feasibility ofmeasuring the flux power spectrum at $z\simeq 6$ using mock quasar spectra andconclude that a sample of $\sim10$ high-resolution spectra with an attainablesignal-to-noise ratio will allow distinguishing between different reionizationscenarios.

Constraining Reionization with the $z \sim 5-6$ Lyman-$\alpha$ Forest Power Spectrum: the Outlook after Planck