Measurements of the $z > 5$ Lyman-$α$ forest flux auto-correlation functions from the extended XQR-30 data set

Molly Wolfson; Joseph F. Hennawi; Sarah E. I. Bosman; Frederick B. Davies; Zarija Lukić; George D. Becker; Huanqing Chen; Guido Cupani; Valentina D'Odorico; Anna-Christina Eilers; Martin G. Haehnelt; Laura C. Keating; Girish Kulkarni; Samuel Lai; Andrei Mesinger; Fabian Walter; Yongda Zhu

arXiv · 2309.03341

Measurements of the $z > 5$ Lyman-$α$ forest flux auto-correlation functions from the extended XQR-30 data set

Molly Wolfson·Joseph F. Hennawi·Sarah E. I. Bosman·Frederick B. Davies·Zarija Lukić·George D. Becker·Huanqing Chen·Guido Cupani·Valentina D'Odorico·Anna-Christina Eilers·Martin G. Haehnelt·Laura C. Keating·Girish Kulkarni·Samuel Lai·Andrei Mesinger·Fabian Walter·Yongda Zhu

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Abstract

Recently, the Lyman-$α$ (Ly$α$) forest flux auto-correlation function has been shown to be sensitive to the mean free path of hydrogen-ionizing photons, $λ_{\text{mfp}}$, for simulations at $z \geq 5.4$. Measuring $λ_{\text{mfp}}$ at these redshifts will give vital information on the ending of reionization. Here we present the first observational measurements of the Ly$α$ forest flux auto-correlation functions in ten redshift bins from $5.1 \leq z \leq 6.0$. We use a sample of 35 quasar sightlines at $z > 5.7$ from the extended XQR-30 data set, this data has signal-to-noise ratios of $> 20$ per spectral pixel. We carefully account for systematic errors in continuum reconstruction, instrumentation, and contamination by damped Ly$α$ systems. With these measurements, we introduce software tools to generate auto-correlation function measurements from any simulation. For an initial comparison, we show our auto-correlation measurements with simulation models for recently measured $λ_{\text{mfp}}$ values and find good agreements. Further work in modeling and understanding the covariance matrices of the data is necessary to get robust measurements of $λ_{\text{mfp}}$ from this data.

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Molly Wolfson, Joseph F. Hennawi, Sarah E. I. Bosman, Frederick B. Davies, Zarija Lukić, George D. Becker, Huanqing Chen, Guido Cupani, Valentina D'Odorico, Anna-Christina Eilers, Martin G. Haehnelt, Laura C. Keating, Girish Kulkarni, Samuel Lai, Andrei Mesinger, Fabian Walter, Yongda Zhu. 2023-09-06. Measurements of the $z > 5$ Lyman-$α$ forest flux auto-correlation functions from the extended XQR-30 data set. https://arxiv.org/abs/2309.03341

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