Related papers: The impact of local stellar radiation on the HI co…
Radiative transfer equilibrium models of nearby interstellar matter (ISM) yield the boundary conditions of the heliosphere when constrained with observations of ISM inside and outside of the heliosphere. Filtration factors for interstellar…
We investigate the effect of helium on hydrogen reionisation using a hydrodynamical simulation combined with the cosmological radiative transfer code CRASH. The simulations are run in a 35.12/h comoving Mpc box using a variety of…
The high ionization-state ions trace the hot gases in the universe, of which gaseous halos around galaxies are a major contributor. Following Qu & Bregman (2018), we calculate the gaseous halo contribution to the observed column density…
We present a survey for optically thick Lyman limit absorbers at z<2.6 using archival Hubble Space Telescope observations with the Faint Object Spectrograph and Space Telescope Imaging Spectrograph. We identify 206 Lyman limit systems…
The deuterium abundance evaluation in the direction of Capella has for a long time been used as a reference for the local interstellar medium (ISM) within our Galaxy. We show here that broad and weak HI components could be present on the…
Carbon monoxide (CO) is a poor tracer of H$_{2}$ in the diffuse interstellar medium (ISM), where most of the carbon is not incorporated into CO molecules unlike the situation at higher extinctions. We present a novel, indirect method to…
We present new simulations of Lyman-$\alpha$ (Ly$\alpha$) intensity maps that include Ly$\alpha$ radiative transfer in the intergalactic medium (IGM) and all significant sources of Ly$\alpha$ photons. The sources considered include…
We performed 3-dimensional N-body/SPH simulations to study how mass resolution and other model parameters such as the star formation efficiency parameter, C* and the threshold density, nth affect structures of the galactic gaseous/stellar…
Diffuse interstellar clouds show large abundances of H_3^+ which can be maintained only by a high ionization rate of H_2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high…
Combing the three-dimensional radiative transfer (RT) calculation and cosmological SPH simulations, we study the escape fraction of ionizing photons (f_esc) of high-redshift galaxies at z=3-6. Our simulations cover the halo mass range of…
Searches for Lyman-alpha emission lines are among the most effective ways to identify high-redshift galaxies. They are particularly interesting because they probe not only the galaxies themselves but also the ionization state of the…
Context: Before the launch of the Swift satellite, the majority of the gamma-ray burst (GRB) afterglows for which Ly-alpha was redshifted into the observable spectrum showed evidence for a damped Ly-alpha absorber. This small sample…
We model the distribution of neutral hydrogen (HI) in the post-reionization era and investigate its detectability in 21 cm intensity mapping with the future SKA radio telescope. We rely on high resolution hydrodynamical N-body simulations.…
Cold, neutral interstellar gas, the reservoir for star formation, is traced through the absorption of the 21-centimetre continuum radiation by neutral hydrogen (HI). Although detected in one hundred cases in the host galaxies of distant…
This work studies the environments and star formation relationships of local luminous infrared galaxies (LIRG) in comparison to other types of local and distant (z~1) galaxies. The infrared (IR) galaxies are drawn from the IRAS sample. The…
We present HI line profiles for various models of circumstellar shells around red giants. In the calculations we take into account the effect of the background at 21 cm, and show that in some circumstances it may have an important effect on…
Far-ultraviolet spectra obtained with $FUSE$ show that the strong $CII\lambda$1036 interstellar absorption-line is essentially black in five of the UV-brightest local starburst galaxies. Since the opacity of the neutral ISM below the…
We use high-resolution cosmological zoom-in simulations from the FIRE project to make predictions for the covering fractions of neutral hydrogen around galaxies at z=2-4. These simulations resolve the interstellar medium of galaxies and…
We use the observed number and column-density distributions of intergalactic O VI absorbers to constrain the distribution of metals in the low-redshift intergalactic medium (IGM). In this simple model the metals in the O VI absorbers are…
We report deep, high spectral resolution WSRT HI 21cm observations of four high latitude compact radio sources, that have revealed a new population of tiny, discrete clouds in the diffuse ISM, with peak optical depths tau ~ 0.1-2%, HI…