Related papers: On the star formation efficiency in high redshift …
We are in the golden age for the search for high-redshift galaxies, made possible by a combination of new instruments and innovative search techniques. One of the major aims of such searches is to constrain the epoch of reionization (EoR),…
At redshifts beyond z>6, as the mean fraction of neutral hydrogen x_HI in the intergalactic medium (IGM) increases, the line flux of Lyman alpha (Lya) emitters can be significantly suppressed, which can result in a decrease in the observed…
We use numerical simulations to study the effects of the patchiness of a partly reionized intergalactic medium (IGM) on the observability of Ly-alpha emitters (LAEs) at high redshifts (z ~ 6). We present a new model that divides the…
Recent measurements of the Luminosity Function (LF) of galaxies in the Epoch of Reionization (EoR, $z\gsim6$) indicate a very steep increase of the number density of low-mass galaxies populating the LF faint-end. However, as star formation…
The fraction of Lyman-$\alpha$ emitters among the galaxy population has been found to increase from $z\sim0$ to $z\sim6$ and drop dramatically at $z>6$. This drop has been interpreted as an effect of an increasingly neutral intergalactic…
The Lyman Continuum photon production efficiency ($\xi_{\rm ion}$) is a critical ingredient for inferring the number of photons available to reionise the intergalactic medium. To estimate the theoretical production efficiency in the…
We present a model to understand the redshift evolution of the UV luminosity and stellar mass functions of Lyman Break Galaxies. Our approach is based on the assumption that the luminosity and stellar mass of a galaxy is related to its dark…
We present spectroscopic Ly$\alpha$ luminosity functions (LFs) at z = 5.7 and z = 6.6 based on a large 209 source sample of Ly$\alpha$ emitter (LAE) candidates identified in Subaru/Hyper Suprime-Cam narrowband imaging and confirmed with…
In this work we model the observed evolution in comoving number density of Lyman-alpha blobs (LABs) as a function of redshift, and try to find which mechanism of emission is dominant in LAB. Our model calculates LAB emission both from…
Four recent observational results have challenged our understanding of high--redshift galaxies, as they require the presence of far more ultraviolet photons than should be emitted by normal stellar populations. First, there is significant…
We present a spectroscopic survey of Ly$\alpha$ emitters (LAEs) at $z\sim3.7$ and $z\sim4.8$. The LAEs are selected using the narrowband technique based on the combination of deep narrowband and broadband imaging data in two deep fields,…
We made a narrowband NB973 (bandwidth of 200A at 9755A) imaging of the Subaru Deep Field (SDF) and found two z=7 Lyman alpha emitter (LAE) candidates down to NB973=24.9. Carrying out deep follow-up spectroscopy, we identified one of them as…
We investigate the implications of our measurement of the Lyman-alpha forest opacity at redshifts 2<z<4.2 from a sample of 86 high-resolution quasar spectra for the evolution of the cosmic ultraviolet luminosity density and its sources. The…
We investigate if systems of multiple Lyman-alpha emitters (LAEs) can serve as a proxy for dark matter halo mass, assess how their radiative properties relate to the underlying halo conditions, and explore the physics of star formation…
One of the major conundrums in contemporary extragalactic astrophysics is the apparent overabundance of a remarkable population of UV-bright galaxies at redshifts $z\gtrsim 9$. We analyse galaxies spectroscopically observed by JWST/NIRSpec…
We present a new measurement of the Ly$\alpha$ luminosity function at redshift $z=6.9$, finding moderate evolution from $z=5.7$ that is consistent with a fully or largely ionized $z\sim7$ intergalactic medium. Our result is based on four…
We present a model for the evolution of the galaxy ultraviolet (UV) luminosity function (LF) across cosmic time where star formation is linked to the assembly of dark matter halos under the assumption of a mass dependent, but redshift…
Lyman alpha (Lya) emission lines should be attenuated in a neutral intergalactic medium (IGM). Therefore the visibility of Lya emitters at high redshifts can serve as a valuable probe of reionization at about the 50% level. We present an…
Several studies have detected Lyman-alpha (Ly$\alpha$) from bright ($M_\mathrm{UV}\lesssim-21.5$) galaxies during the early stages of reionization despite the significantly neutral intergalactic medium. To explain these detections, it has…
We investigate the burstiness of star formation and the ionizing efficiency of a large sample of galaxies at $0.7 < z < 1.5$ using HST grism spectroscopy and deep ultraviolet (UV) imaging in the GOODS-N and GOODS-S fields. The star…