Related papers: SOAP and the Interstellar Froth
We present a detailed analysis of the ionization and thermal structure of the intergalactic medium (IGM) around a high-redshift QSO using a large suite of cosmological, multi-frequency radiative transfer (RT) simulations, exploring the…
We present new models for the X-ray photoevaporation of circumstellar discs which suggest that the resulting mass loss (occurring mainly over the radial range 10-40 AU) may be the dominant dispersal mechanism for gas around low mass…
The Magellanic Stream and several high velocity clouds have now been detected in optical line emission. The observed emission measures and kinematics are most plausibly explained by photoionization due to hot, young stars in the Galactic…
Following our study on the incidence, morphology and kinematics of the ionised gas in early-type galaxies we now address the question of what is powering the observed nebular emission. To constrain the likely sources of gas excitation, we…
We have studied the spectral characteristics of the Diffuse Ionized Gas in two irregular galaxies with low metallicities and intermediate Star Formation Rates: ESO 245-G05 and Gr 8. The [OIII]/Hbeta in these galaxies is higher than in the…
Gaseous, disk-halo interfaces are shaped by processes that are critical to galaxy evolution, including gas accretion and outflows. Extraplanar diffuse ionized gas (eDIG) layers are characterized by scale heights that largely exceed those…
We investigate the impact of nonequilibrium ionisation (NEI) and the metagalactic radiation-field on the thermal evolution, virial shock stability, and absorption signatures of gas surrounding galaxies. Using 1D, spherically symmetric…
The hot gas in galaxy halos may account for a significant fraction of missing baryons in galaxies, and some of these gases can be traced by high ionization absorption systems in QSO UV spectra. Using high S/N ratio $ HST$/COS spectra, we…
Single-phase photoionization equilibrium (PIE) models are often used to infer the underlying physical properties of galaxy halos probed in absorption with ions at different ionization potentials. To incorporate the effects of turbulence, we…
We compare the three-dimensional gas temperature distributions obtained by a dedicated radiative transfer and photoionisation code, MOCASSIN, against those obtained by the recently-developed Smooth Particle Hydrodynamics (SPH) plus…
Photoionization models of HII regions require as input a description of the ionizing SED and of the gas distribution, in terms of ionization parameter U and chemical abundances (e.g. O/H and N/O). A strong degeneracy exists between the…
Chemistry in diffuse molecular clouds relies primarily on rapid ion-molecule reactions. Formation of the initial ions, H$^+$ and H$_2^+$, is dominated by cosmic-ray ionization of H and H$_2$, making the cosmic-ray ionization rate (denoted…
We present synthetic dust polarisation maps of 3D magneto-hydrodynamical simulations of molecular clouds before the onset of stellar feedback. The clouds are modelled within the SILCC-Zoom project and are embedded in their galactic…
Early in the reionization process, the intergalactic medium (IGM) would have been quite inhomogeneous on small scales, due to the low Jeans mass in the neutral IGM and the hierarchical growth of structure in a cold dark matter Universe.…
A recent astroph posting argued that the Gould (2003a) halo sample is substantially contaminated with thick-disk stars, which would then ``wash out'' any signature of granularity in the halo velocity distribution due to streams. If correct,…
The Diffuse Ionized Gas (DIG) contributes to the nebular emission of galaxies, resulting in emission line flux ratios that can be significantly different from those produced by HII regions. Comparing the emission of [SII]6717,31 between…
In this work, we study the basic statistical properties of HI-selected galaxies extracted from six different semi-analytic models, all run on the same cosmological N-body simulation. One model includes an explicit treatment for the…
We present the Bidimensional Exploration of the warm-Temperature Ionised gaS (BETIS) project, designed for the spatial and spectral study of the diffuse ionised gas (DIG) in a selection of nearby spiral galaxies observed with the MUSE…
We apply our three dimensional photoionization code to model Wisconsin H-alpha Mapper observations of the H II region surrounding the O9.5V star Zeta Oph. Our models investigate the porosity of the interstellar medium around zeta Oph and…
The [O II] 3727 emission line is often used as an indicator of star formation rate in extragalactic surveys, and it can be an equally effective tracer of star formation in systems containing luminous active galactic nuclei (AGNs). In order…