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Deep learning the intergalactic medium using lyman-alpha forest at 4 ≤ z ≤ 5 (2024)
Journal Article
Nasir, F., Gaikwad, P., Davies, F. B., Bolton, J. S., Puchwein, E., & Bosman, S. E. I. (2024). Deep learning the intergalactic medium using lyman-alpha forest at 4 ≤ z ≤ 5. Monthly Notices of the Royal Astronomical Society, 534(2), 1299–1316. https://doi.org/10.1093/mnras/stae2153

Unveiling the thermal history of the intergalactic medium (IGM) at 4 ≤z ≤5 holds the potential to reveal early onset He II reionization or lingering thermal fluctuations from H I reionization. We set out to reconstruct the IGM gas properties along si... Read More about Deep learning the intergalactic medium using lyman-alpha forest at 4 ≤ z ≤ 5.

Damping wing absorption associated with a giant Ly α trough at z < 6: direct evidence for late-ending reionization (2024)
Journal Article
Becker, G. D., Bolton, J. S., Zhu, Y., & Hashemi, S. (2024). Damping wing absorption associated with a giant Ly α trough at z < 6: direct evidence for late-ending reionization. Monthly Notices of the Royal Astronomical Society, 533(2), 1525–1540. https://doi.org/10.1093/mnras/stae1918

Multiple observations now suggest that the hydrogen reionization may have ended well below redshift six. While there has previously been no conclusive proof of extended neutral islands in the z < 6 intergalactic medium, it is possible that such islan... Read More about Damping wing absorption associated with a giant Ly α trough at z < 6: direct evidence for late-ending reionization.

Late-end reionization with aton-he: towards constraints from Ly α emitters observed with JWST (2024)
Journal Article
Shikhar, A., Martin G., H., Girish, K., Dominique, A., James S., B., & Laura C., K. (2024). Late-end reionization with aton-he: towards constraints from Ly α emitters observed with JWST. Monthly Notices of the Royal Astronomical Society, 533(3), 2843-2866. https://doi.org/10.1093/mnras/stae1945

We present a new suite of late-end reionization simulations performed with ATON-HE, a revised version of the GPU-based radiative transfer code ATON that includes helium. The simulations are able to reproduce the Ly α flux distribution of the E-XQR-30... Read More about Late-end reionization with aton-he: towards constraints from Ly α emitters observed with JWST.

The Lyman-limit photon mean free path at the end of late reionization in the Sherwood–Relics simulations (2024)
Journal Article
Feron, J., Conaboy, L., Bolton, J. S., Chapman, E., Haehnelt, M. G., Keating, L. C., Kulkarni, G., & Puchwein, E. (2024). The Lyman-limit photon mean free path at the end of late reionization in the Sherwood–Relics simulations. Monthly Notices of the Royal Astronomical Society, 532(2), 2401-2417. https://doi.org/10.1093/mnras/stae1636

Recent evidence supporting reionization ending at redshift z ≲ 6 includes the rapid redshift evolution of the mean free path, λmfp , for Lyman-limit photons through the intergalactic medium (IGM) at 5 < z < 6. Here, we investigate λmfp predicted by t... Read More about The Lyman-limit photon mean free path at the end of late reionization in the Sherwood–Relics simulations.

Damping wing-like features in the stacked Ly α forest: Potential neutral hydrogen islands at z < 6 (2024)
Journal Article
Zhu, Y., Becker, G. D., Bosman, S. E. I., Cain, C., Keating, L. C., Nasir, F., D’Odorico, V., Bañados, E., Bian, F., Bischetti, M., Bolton, J. S., Chen, H., D’Aloisio, A., Davies, F. B., Davies, R. L., Eilers, A.-C., Fan, X., Gaikwad, P., Greig, B., Haehnelt, M. G., …Yang, J. (2024). Damping wing-like features in the stacked Ly α forest: Potential neutral hydrogen islands at z < 6. Monthly Notices of the Royal Astronomical Society: Letters, 533(1), L49-L56. https://doi.org/10.1093/mnrasl/slae061

Recent quasar absorption line observations suggest that reionization may end as late as z ≈ 5.3. As a means to search for large neutral hydrogen islands at z < 6, we revisit long dark gaps in the Ly β forest in Very Large Telescope/X-Shooter and Keck... Read More about Damping wing-like features in the stacked Ly α forest: Potential neutral hydrogen islands at z < 6.

JWST observations of galaxy damping wings during reionization interpreted with cosmological simulations (2024)
Journal Article
Keating, L. C., Bolton, J. S., Cullen, F., Haehnelt, M. G., Puchwein, E., & Kulkarni, G. (2024). JWST observations of galaxy damping wings during reionization interpreted with cosmological simulations. Monthly Notices of the Royal Astronomical Society, 532(2), 1646–1658. https://doi.org/10.1093/mnras/stae1530

Spectra of the highest redshift galaxies taken with JWST are now allowing us to see into the heart of the reionization epoch. Many of these observed galaxies exhibit strong damping wing absorption redward of their Lyman-α emission. These observations... Read More about JWST observations of galaxy damping wings during reionization interpreted with cosmological simulations.

The origin of the characteristic shape and scatter of intergalactic damping wings during reionization (2024)
Journal Article
Keating, L. C., Puchwein, E., Bolton, J. S., Haehnelt, M. G., & Kulkarni, G. (2024). The origin of the characteristic shape and scatter of intergalactic damping wings during reionization. Monthly Notices of the Royal Astronomical Society: Letters, 531(1), L34-L39. https://doi.org/10.1093/mnrasl/slae022

Ly α damping wings in the spectra of bright objects at high redshift are a useful probe of the ionization state of the intergalactic medium during the reionization epoch. It has recently been noted that, despite the inhomogeneous nature of reionizati... Read More about The origin of the characteristic shape and scatter of intergalactic damping wings during reionization.

Particle initialization effects on Lyman- αforest statistics in cosmological SPH simulations (2024)
Journal Article
Khan, N. K., Kulkarni, G., Bolton, J. S., Haehnelt, M. G., Iršič, V., Puchwein, E., & Asthana, S. (2024). Particle initialization effects on Lyman- αforest statistics in cosmological SPH simulations. Monthly Notices of the Royal Astronomical Society, 530(4), 4920-4935. https://doi.org/10.1093/mnras/stae662

Confronting measurements of the Lyman- αforest with cosmological hydrodynamical simulations has produced stringent constraints on models of particle dark matter and the thermal and ionization state of the intergalactic medium. We investigate the robu... Read More about Particle initialization effects on Lyman- αforest statistics in cosmological SPH simulations.

Unveiling dark matter free streaming at the smallest scales with the high redshift Lyman-alpha forest (2024)
Journal Article
Iršič, V., Viel, M., Haehnelt, M. G., Bolton, J. S., Molaro, M., Puchwein, E., …Kulkarni, G. (2024). Unveiling dark matter free streaming at the smallest scales with the high redshift Lyman-alpha forest. Physical Review D, 109(4), Article 043511. https://doi.org/10.1103/physrevd.109.043511

This study introduces novel constraints on the free streaming of thermal relic warm dark matter (WDM) from Lyman-α forest flux power spectra. Our analysis utilizes a high resolution, high redshift sample of quasar spectra observed using the HIRES and... Read More about Unveiling dark matter free streaming at the smallest scales with the high redshift Lyman-alpha forest.

Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at 4.9≤z≤6.0 from a large sample of XShooter and ESI spectra (2023)
Journal Article
Gaikwad, P., Haehnelt, M. G., Davies, F. B., Bosman, S. E. I., Molaro, M., Kulkarni, G., …Eilers, A.-C. (2023). Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at 4.9≤z≤6.0 from a large sample of XShooter and ESI spectra. Monthly Notices of the Royal Astronomical Society, 525(3), 4093-4120. https://doi.org/10.1093/mnras/stad2566

We measure the mean free path (⁠λmfp,HI⁠), photo-ionization rate (⁠⟨ΓHI⟩⁠) and neutral fraction (⁠⟨fHI⟩⁠) of hydrogen in 12 redshift bins at 4.85 < z < 6.05 from a large sample of moderate resolution XShooter and ESI QSO absorption spectra. The fluct... Read More about Measuring the photo-ionization rate, neutral fraction and mean free path of HI ionizing photons at 4.9≤z≤6.0 from a large sample of XShooter and ESI spectra.

Possible evidence for a large-scale enhancement in the Lyman-α forest power spectrum at redshift z ≥ 4 (2023)
Journal Article
Molaro, M., Iršič, V., Bolton, J. S., Lieu, M., Keating, L. C., Puchwein, E., …Viel, M. (2023). Possible evidence for a large-scale enhancement in the Lyman-α forest power spectrum at redshift z ≥ 4. Monthly Notices of the Royal Astronomical Society, 521(1), 1489–1501. https://doi.org/10.1093/mnras/stad598

Inhomogeneous reionization enhances the 1D Ly α forest power spectrum on large scales at redshifts z ≥ 4. This is due to coherent fluctuations in the ionized hydrogen fraction that arise from large-scale variations in the post-reionization gas temper... Read More about Possible evidence for a large-scale enhancement in the Lyman-α forest power spectrum at redshift z ≥ 4.

The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium (2022)
Journal Article
Puchwein, E., Bolton, J. S., Keating, L. C., Molaro, M., Gaikwad, P., Kulkarni, G., …Meiksin, A. (2023). The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium. Monthly Notices of the Royal Astronomical Society, 519(4), 6162-6183. https://doi.org/10.1093/mnras/stac3761

We present the Sherwood-Relics simulations, a new suite of large cosmological hydrodynamical simulations aimed at modelling the intergalactic medium (IGM) during and after the cosmic reionization of hydrogen. The suite consists of over 200 simulation... Read More about The Sherwood-Relics simulations: overview and impact of patchy reionization and pressure smoothing on the intergalactic medium.

Probing quasar lifetimes with proximate 21-centimetre absorption in the diffuse intergalactic medium at redshifts z ≥ 6 (2022)
Journal Article
Šoltinský, T., Bolton, J. S., Molaro, M., Hatch, N., Haehnelt, M. G., Keating, L. C., …Puchwein, E. (2023). Probing quasar lifetimes with proximate 21-centimetre absorption in the diffuse intergalactic medium at redshifts z ≥ 6. Monthly Notices of the Royal Astronomical Society, 519(2), 3027-3045. https://doi.org/10.1093/mnras/stac3710

Enhanced ionizing radiation in close proximity to redshift z ≳ 6 quasars creates short windows of intergalactic Ly α transmission blueward of the quasar Ly α emission lines. The majority of these Ly α near-zones are consistent with quasars that have... Read More about Probing quasar lifetimes with proximate 21-centimetre absorption in the diffuse intergalactic medium at redshifts z ≥ 6.

Comparison of Low-Redshift Lyman- α Forest Observations to Hydrodynamical Simulations with Dark Photon Dark Matter (2022)
Journal Article
Bolton, J. S., Caputo, A., Liu, H., & Viel, M. (2022). Comparison of Low-Redshift Lyman- α Forest Observations to Hydrodynamical Simulations with Dark Photon Dark Matter. Physical Review Letters, 129(21), Article 211102. https://doi.org/10.1103/physrevlett.129.211102

Recent work has suggested that an additional ≲6.9 eV per baryon of heating in the intergalactic medium is needed to reconcile hydrodynamical simulations with Lyman-α forest absorption line widths at redshift z≃0.1. Resonant conversion of dark photon... Read More about Comparison of Low-Redshift Lyman- α Forest Observations to Hydrodynamical Simulations with Dark Photon Dark Matter.

Limits on non-canonical heating and turbulence in the intergalactic medium from the low redshift Lyman α forest (2022)
Journal Article
Bolton, J. S., Gaikwad, P., Haehnelt, M. G., Kim, T. S., Nasir, F., Puchwein, E., …Wakker, B. P. (2022). Limits on non-canonical heating and turbulence in the intergalactic medium from the low redshift Lyman α forest. Monthly Notices of the Royal Astronomical Society, 513(1), 864-885. https://doi.org/10.1093/mnras/stac862

We examine the column density distribution function (CDDF) and Doppler parameter distribution from hydrodynamical simulations and Cosmic Origins Spectrograph (COS) observations of the Ly α forest at redshift 0 ≤ z ≤ 0.2. Allowing for a factor of two... Read More about Limits on non-canonical heating and turbulence in the intergalactic medium from the low redshift Lyman α forest.

The effect of inhomogeneous reionization on the Lyman α forest power spectrum at redshift z > 4: implications for thermal parameter recovery (2021)
Journal Article
Molaro, M., Iršič, V., Bolton, J. S., Keating, L. C., Puchwein, E., Gaikwad, P., …Viel, M. (2022). The effect of inhomogeneous reionization on the Lyman α forest power spectrum at redshift z > 4: implications for thermal parameter recovery. Monthly Notices of the Royal Astronomical Society, 509(4), 6119-6137. https://doi.org/10.1093/mnras/stab3416

We use the Sherwood–Relics suite of hybrid hydrodynamical and radiative transfer simulations to model the effect of inhomogeneous reionization on the 1D power spectrum of the Lyman α (Lyα) forest transmitted flux at redshifts 4.2 ≤ z ≤ 5. Relative to... Read More about The effect of inhomogeneous reionization on the Lyman α forest power spectrum at redshift z > 4: implications for thermal parameter recovery.

The effect of inhomogeneous reionisation on the Lyman-alpha forest power spectrum at redshift z > 4: implications for thermal parameter recovery (2021)
Journal Article
Molaro, M., Iršič, V., BOLTON, J. S., Keating, L. C., Puchwein, E., Gaikwad, P., …Viel, M. (2021). The effect of inhomogeneous reionisation on the Lyman-alpha forest power spectrum at redshift z > 4: implications for thermal parameter recovery. Monthly Notices of the Royal Astronomical Society, 509(4), 6119–6137. https://doi.org/10.1093/mnras/stab3416

We use the Sherwood–Relics suite of hybrid hydrodynamical and radiative transfer simulations to model the effect of inhomogeneous reionization on the 1D power spectrum of the Lyman α (Lyα) forest transmitted flux at redshifts 4.2 ≤ z ≤ 5. Relative to... Read More about The effect of inhomogeneous reionisation on the Lyman-alpha forest power spectrum at redshift z > 4: implications for thermal parameter recovery.

The mean free path of ionizing photons at 5 &lt; z &lt; 6: evidence for rapid evolution near reionization (2021)
Journal Article
Becker, G. D., D’Aloisio, A., Christenson, H. M., Zhu, Y., Worseck, G., & Bolton, J. S. (2021). The mean free path of ionizing photons at 5 &lt; z &lt; 6: evidence for rapid evolution near reionization. Monthly Notices of the Royal Astronomical Society, 508(2), 1853-1869. https://doi.org/10.1093/mnras/stab2696

The mean free path of ionizing photons, λmfp, is a key factor in the photoionization of the intergalactic medium (IGM). At z ≳ 5, however, λmfp may be short enough that measurements towards QSOs are biased by the QSO proximity effect. We present new... Read More about The mean free path of ionizing photons at 5 &lt; z &lt; 6: evidence for rapid evolution near reionization.

Searching for the shadows of giants II: the effect of local ionisation on the Lyman-alpha absorption signatures of protoclusters at redshift z=2.4 (2021)
Journal Article
Miller, J., Bolton, J., & Hatch, N. (2021). Searching for the shadows of giants II: the effect of local ionisation on the Lyman-alpha absorption signatures of protoclusters at redshift z=2.4. Monthly Notices of the Royal Astronomical Society, 506(4), 6001-6013. https://doi.org/10.1093/mnras/stab2083

Local variations in the intergalactic medium (IGM) neutral hydrogen fraction will affect the Ly α absorption signature of protoclusters identified in tomographic surveys. Using the IllustrisTNG simulations, we investigate how the AGN proximity effect... Read More about Searching for the shadows of giants II: the effect of local ionisation on the Lyman-alpha absorption signatures of protoclusters at redshift z=2.4.

The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models (2021)
Journal Article
Šoltinsky, T., Bolton, J. S., Hatch, N., Haehnelt, M. G., Keating, L. C., Kulkarni, G., …Aubert, D. (2021). The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models. Monthly Notices of the Royal Astronomical Society, 506(4), 5818-5835. https://doi.org/10.1093/mnras/stab1830

A late end to reionization at redshift z 5.3 is consistent with observed spatial variations in the Ly α forest transmission and the deficit of Ly α emitting galaxies around extended Ly α absorption troughs at z = 5.5. In this model, large islands of... Read More about The detectability of strong 21-cm forest absorbers from the diffuse intergalactic medium in late reionization models.