Related papers: Project Lyman: Quantifying 11 Gyrs of Metagalactic…
We investigate the implications of the intergalactic opacity for the evolution of the cosmic UV luminosity density and its sources. Our main constraint is our measurement of the Lya forest opacity at redshifts 2<z<4.2 from 86…
The source responsible for the reionization of the Universe is believed to be the population of star-forming galaxies at $z\sim6$ to 12. The biggest uncertainty concerns the fraction of Lyman-continuum photons that actually escape from the…
The fraction of ionizing photons that escape their host galaxies and so are able to ionize hydrogen in the inter-galactic medium (IGM) is a critical parameter in analyses of the reionization era and early galaxy formation. Studies of the…
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…
We have modelled the process of reionization of the IGM by photoionization by galaxies, in order to predict the epoch of reionization. We use a sophisticated semi-analytic model to track the formation of galaxies. Our study represents a…
We aim to investigate the effect of the escaping ionizing radiation on the color selection of high redshift galaxies and identify candidate Lyman continuum (LyC) emitters. The intergalactic medium prescription of Inoue et al.(2014) and…
JWST has recently sparked a new era of Ly$\alpha$ spectroscopy, delivering the first measurements of the Ly$\alpha$ escape fraction and velocity profile in typical galaxies at $z\simeq6-10$. These observations offer new prospects for…
We present results from a new Keck spectroscopic survey of UV-faint LBGs in the redshift range 3<z<7. Combined with earlier Keck and published ESO VLT data, our sample contains more than 600 dropouts, offering new insight into the nature of…
Early results from the JWST observations have reported a surprisingly high number of UV-bright galaxies at $z \geq 10$, which appears to challenge the theoretical predictions from standard galaxy formation models in the $\Lambda$CDM…
There has been great progress in recent years in discovering star forming galaxies at high redshifts (z>5), close to the epoch of reionization of the intergalactic medium (IGM). The WFC3 and ACS cameras on the Hubble Space Telescope have…
The rapidly declining population of bright quasars at z~3 appears to make an increasingly small contribution to the ionising background at the HI Lyman limit. It is then generally though that massive stars in (pre-)galactic systems may…
High-resolution numerical simulations including feedback and aimed at calculating the escape fraction (fesc) of hydrogen-ionizing photons often assume stellar radiation based on single-stellar population synthesis models. However, strong…
Star-forming dwarf galaxies leaking Lyman-continuum (LyC) radiation may have played an important role in the reionization of the Universe. Local galaxies exhibiting LyC leakage could shed light on the escape mechanisms, but so far only two…
Low- and intermediate mass galaxies are widely discussed as cause of reionization at redshift $z\sim10-6$. However, observational proof of galaxies that are leaking ionizing radiation (Lyman continuum; LyC) is a currently ongoing challenge…
Faint galaxies are theorised to have played a major role in reionising the Universe. Their properties as well as the Lyman-{\alpha} emitter fraction, could provide useful insight into this epoch. We use four galaxy clusters from the Lensed…
Star-forming galaxies are considered to be the leading candidate sources that dominate the cosmic reionization at z>7, and the search for analogs at moderate redshift showing Lyman continuum (LyC) leakage is currently a active line of…
Knowing the amount of ionizing photons from young star-forming galaxies is of particular importance to understanding the reionization process. Here we report initial results of Subaru/Suprime-Cam deep imaging observation of the SSA22…
The escape fraction of ionizing photons from galaxies is a crucial quantity controlling the cosmic ionizing background radiation and the reionization. Various estimates of this parameter can be obtained in the redshift range, z=0--6, either…
The discovery of Lyman-alpha emission from galaxies at redshifts beyond z~6.5 should not be naively interpreted as implying that the intergalactic medium (IGM) had been reionized at higher redsifts. We show that a cluster of faint…
Determining the average fraction of Lyman continuum (LyC) photons escaping high redshift galaxies is essential for understanding how reionization proceeded in the z>6 Universe. We want to measure the LyC signal from a sample of sources in…