Skip to main content

Research Repository

Advanced Search

Outputs (5)

An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties (2007)
Journal Article
-S. Kim, T., S. Bolton, J., Viel, M., G. Haehnelt, M., & F. Carswell, R. (2007). An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties. Monthly Notices of the Royal Astronomical Society, 382(4), 1657–1674. https://doi.org/10.1111/j.1365-2966.2007.12406.x

We have performed an extensive Voigt profile analysis of the neutral hydrogen (HI) and metal absorption present in a sample of 18 high resolution, high signal-to-noise QSO spectra observed with VLT/UVES. We use this analysis to separate the metal con... Read More about An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties.

A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium (2007)
Journal Article
S. Bolton, J., & G. Haehnelt, M. (2007). A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium. Monthly Notices of the Royal Astronomical Society: Letters, 381(1), L35-L39. https://doi.org/10.1111/j.1745-3933.2007.00361.x

We examine a large set of synthetic quasar spectra to realistically assess the potential of using the relative sizes of highly ionized near-zones in the Lya and Lyb forest as a probe of the neutral hydrogen content of the intergalactic medium (IGM) a... Read More about A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium.

The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization (2007)
Journal Article
S. Bolton, J., & G. Haehnelt, M. (2007). The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization. Monthly Notices of the Royal Astronomical Society, 382(1), 325–341. https://doi.org/10.1111/j.1365-2966.2007.12372.x

We use a large set of hydrodynamical simulations, combined with measurements of the Lyman alpha opacity of the IGM taken from the literature, to obtain robust estimates for the photoionization rate per hydrogen atom at z=5 and 6. We find the photoion... Read More about The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization.