Related papers: Modeling of diffuse molecular gas applied to HD 10…
Modelling the molecular gas that is routinely detected through CO observations of high-redshift galaxies constitutes a major challenge for ab initio simulations of galaxy formation. We carry out a suite of cosmological hydrodynamic…
We present an analysis of Spitzer-IRS spectroscopic maps of the L1157 protostellar outflow in the H2 pure-rotational lines from S(0) to S(7). The aim of this work is to derive the physical conditions pertaining to the warm molecular gas and…
To provide constraints on the chemical processes responsible for the observed columns of organic species, we used NOEMA to observe the sight line toward NRAO150 in the 2mm spectral window. We targeted the low excitation lines of o-H2CO…
We report medium resolution VLT ISAAC K-band spectroscopy of the nuclei of seven ultraluminous infrared galaxies. After accounting for stellar absorption features, we have detected several molecular hydrogen (H_2) v=1-0, 2-1, and 3-2…
We observed $\lambda$3mm \cotw, \coth, \coei, \hcop, HCN and CS emission from diffuse molecular gas along sightlines with \EBV\ $\approx$ 0.1 - 1 mag. Directions were mostly chosen for their proximity to sightlines toward background mm-wave…
In the Halo21 absorption modeling challenge we generated synthetic absorption spectra of the circumgalactic medium (CGM), and attempted to estimate the metallicity, temperature, and density (Z, T, and nH) of the underlying gas using…
We examine several different simplified approaches for modelling the chemistry of CO in three-dimensional numerical simulations of turbulent molecular clouds. We compare the different models both by looking at the behaviour of integrated…
H2 is the most abundant molecule in the interstellar medium and is a useful tool to study photodissociation regions, where radiative feedback from massive stars on molecular clouds is dominant. The James Webb Space Telescope, with its high…
We report on strong H2 and CO absorption from gas within the host galaxy of gamma-ray burst (GRB) 080607. Analysis of our Keck/LRIS afterglow spectrum reveals a very large HI column density (NHI = 10^22.70 cm^-2) and strong metal-line…
We investigate how the X factor, the ratio of H_2 column density (NH2) to velocity-integrated CO intensity (W), is determined by the physical properties of gas in model molecular clouds (MCs). We perform radiative transfer calculations on…
Recent observations with the Submillimeter Wave Astronomy Satellite indicate abundances of gaseous H2O and O2 in dense molecular clouds which are significantly lower than found in standard homogeneous chemistry models. We present here…
As a complement to the HyGAL Stratospheric Observatory for Infrared Astronomy Legacy Program, we report the results of a ground-based absorption line survey of simple molecules in diffuse and translucent Galactic clouds. Using the Institut…
Some astrophysical observations of molecular hydrogen point to a broadening of the velocity distribution for molecules at excited rotational levels. This effect is observed in both Galactic and high redshift clouds. Analysis of H_2, HD, and…
We have mapped the warm molecular gas traced by the H_2 S(0) - H_2 S(5) pure rotational mid-infrared emission lines over a radial strip across the nucleus and disk of M51 (NGC 5194) using the Infrared Spectrograph (IRS) on the Spitzer Space…
(Abridged) Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation molecular and atomic emission lines. In this work we present spectro-imaging observations of the HH211 system…
The process of atomic-to-molecular (HI-to-H$_2$) gas conversion is fundamental for molecular-cloud formation and star formation. 21 cm observations of the star-forming region W43 revealed extremely high HI column densities, of 120-180…
Estimating molecular abundances ratios from the direct measurement of the emission of the molecules towards a variety of interstellar environments is indeed very useful to advance in our understanding of the chemical evolution of the…
We examine the triggering process of molecular cloud formation around diffuse HII regions. We calculate the time evolution of the shell as well as of the HII region in a two-phase neutral medium, solving the UV and FUV radiative transfer,…
Hydrogen sulfide (H$_2$S) is thought to be efficiently formed on grain surfaces through the successive hydrogenation of S atoms. Its non-detection so far in astronomical observations of icy dust mantles thus indicates that effective…
Stars form in cold molecular clouds. However, molecular gas is difficult to observe because the most abundant molecule (H2) lacks a permanent dipole moment. Rotational transitions of CO are often used as a tracer of H2, but CO is much less…