Cover Image

First constraints on the local ionization topology in front of two quasars at z ∼ 7.5

Thus far, Lyman-α damping wings towards quasars have been used to probe the global ionization state of the foreground intergalactic medium (IGM). A new parametrization has demonstrated that the damping wing signature also carries local information about the distribution of neutral hydrogen (H i) in...

Full description

Saved in:
Bibliographic Details
Main Authors: Kist, Timo (Author) , Hennawi, Joseph F (Author) , Davies, Frederick B. (Author) , Bañados Torres, Eduardo (Author) , Bosman, Sarah (Author) , Cai, Zheng (Author) , Eilers, Anna-Christina (Author) , Fan, Xiaohui (Author) , Haiman, Zoltán (Author) , Jun, Hyunsung D (Author) , Liu, Yichen (Author) , Yang, Jinyi (Author) , Wang, Feige (Author)
Format: Article (Journal)
Language:English
Published: 2025 December 17
In: Monthly notices of the Royal Astronomical Society
Year: 2026, Volume: 545, Issue: 3, Pages: 1-7
ISSN:1365-2966
DOI:10.1093/mnras/staf2219
Online Access:Verlag, kostenfrei, Volltext: https://doi.org/10.1093/mnras/staf2219
Verlag, kostenfrei, Volltext: https://academic.oup.com/mnras/article/545/3/staf2219/8382488?login=true
Get full text
Author Notes:Timo Kist, Joseph F. Hennawi, Frederick B. Davies, Eduardo Bañados, Sarah E.I. Bosman, Zheng Cai, Anna-Christina Eilers, Xiaohui Fan, Zoltán Haiman, Hyunsung D. Jun, Yichen Liu, Jinyi Yang and Feige Wang
Description
Summary:Thus far, Lyman-α damping wings towards quasars have been used to probe the global ionization state of the foreground intergalactic medium (IGM). A new parametrization has demonstrated that the damping wing signature also carries local information about the distribution of neutral hydrogen (H i) in front of the quasar before it started shining. Leveraging a recently introduced Bayesian jax-based Hamiltonian Monte Carlo inference framework, we derive constraints on the Lorentzian-weighted H i column density N HI DW, the quasar’s distance r patch to the first neutral patch, and its lifetime tQ based on James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec) spectra of the two z ∼ 7.5 quasars J1007+2115 and J1342+0928. After folding in model-dependent topology information, we find that J1007+2115 (and J1342+0928) is most likely to reside in a <x HI> = 0.32 +0.22 -0.20 (0.58 +0.23 -0.23) neutral IGM while shining for a remarkably short lifetime of log 10 tQ/yr = 4.14 0.74 -0.18 (an intermediate lifetime of 5.64 +0.25 -0.43) along a sightline with log 10 N HI DW/cm -2 = 19.70 +0.35 - 0.86 (20.24 +0.25 -0.22) and rpatch= 28.9 -14.4 +54.0 cMpc 10.9 -5.9 +5.6 cMpc). In light of the potential presence of local absorbers in the foreground of J1342+0928 as has been recently suggested, we also demonstrate how the Lorentzian-weighted column density N HI DW provides a natural means for quantifying their contribution to the observed damping wing signal.
Item Description:Im Titel ist [approximately equal] als mathematisches Zeichen dargestellt
Gesehen am 02.04.2026
Physical Description:Online Resource
ISSN:1365-2966
DOI:10.1093/mnras/staf2219

Similar Items