Forecast for the detectability of patchy hydrogen reionization in WEAVE-QSO measurements of the Lyman-α forest power spectrum at redshift z ≥ 4
Abstract We present the first detailed forecasts for the detectability of patchy hydrogen reionization in the one-dimensional Lyα forest power spectrum to be measured by the WEAVE-QSO survey. Using the Sherwood-relics reionization simulations and a WEAVE-QSO survey configuration, we generate mock spectra in four redshift bins, z = 4.0, 4.2, 4.4, and 4.6, in which relic ionization and temperature fluctuations from patchy hydrogen reionization enhance the Lyα forest power spectrum on large scales (i.e., at wavenumber $k\sim 10^{-3}\rm \, s\, km^{-1}$). Our Lyα forest pipeline forecasts the power spectrum covariance by considering sample size, spectral resolution, noise subtraction, continuum placement, metal contamination, and damping wings from high-column density absorbers. Applying our covariance forecast within a Bayesian parameter inference framework, we find that the signature of patchy hydrogen reionization should be detectable at a significance of ≃ 4.5σ. The forthcoming WEAVE-QSO 1D power spectrum measurements should therefore be able to directly detect and characterize the large-scale relic imprint of patchy hydrogen reionization in the Lyα forest power spectrum at z ≥ 4.
Authors
- Rajeshwari Dutta (ORCID: https://orcid.org/0000-0002-6095-7627)
- Vid Iršič (ORCID: https://orcid.org/0000-0002-5445-461X)
- Prakash Gaikwad (ORCID: https://orcid.org/0000-0002-2423-7905)
- F. Pistis (ORCID: https://orcid.org/0000-0003-1189-2617)
- Michele Fumagalli (ORCID: https://orcid.org/0000-0001-6676-3842)
- E. Gafton (ORCID: https://orcid.org/0000-0003-0781-6638)
- James S. Bolton (ORCID: https://orcid.org/0000-0003-2764-8248)
- Matthew M. Pieri (ORCID: https://orcid.org/0000-0003-0247-8991)
- Matteo Fossati (ORCID: https://orcid.org/0000-0002-9043-8764)
- Trystyn A. M. Berg (ORCID: https://orcid.org/0000-0002-2606-5078)
- Ke Ma
- Ignasi Pérez Ràfols
Institutions
- Camosun College (CA)
- Centre National de la Recherche Scientifique (FR)
- University of Hertfordshire (GB)
- University of Nottingham (GB)
- Aix-Marseille Université (FR)
- Trieste Astronomical Observatory (IT)
- Brera Astronomical Observatory (IT)
- National Centre for Nuclear Research (PL)
- Laboratoire d’Astrophysique de Marseille (FR)
- Isaac Newton Group (ES)
- Inter-University Centre for Astronomy and Astrophysics (IN)
- Indian Institute of Technology Indore (IN)
- University of Milano-Bicocca (IT)
- National Institute for Astrophysics (IT)
- Universitat Politècnica de Catalunya (ES)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2026-10-29
- DOI
- https://doi.org/10.1093/mnras/stag2028
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- UK Research and Innovation
- University of Cambridge
- Partnership for Advanced Computing in Europe AISBL
- China Scholarship Council
- Science and Technology Facilities Council