Related papers: The Horsehead nebula, a template source for inters…

(abridged) [...] Methods: In a continued study of the molecular core population of the Pipe Nebula, we present a molecular-line survey of 52 cores. Previous research has shown a variety of different chemical evolutionary stages among the…

The IceCube detector, using its densely instrumented center, called DeepCore, can detect multi-GeV atmospheric neutrinos. The oscillation pattern of neutrinos is altered due to interactions with ambient electrons as they pass through Earth.…

We present observations of molecular high-energy radiation probes and report the first detections of CO+ toward W3 IRS5, a source containing ultracompact HII regions. UV radiation and X-rays from the central objects may enhance molecules…

Using visible, radio, microwave, and sub-mm data, we study several lines of sight toward stars generally closer than 1 kpc on a component-by-component basis. We derive the component structure seen in absorption at visible wavelengths from…

Our main purpose is to estimate the effect of assuming uniform density on the line-of-sight in PDR chemistry models, compared to a more realistic distribution for which total gas densities may well vary by several orders of magnitude. A…

Characterizing the spatial and velocity structure of molecular clouds is a first step towards a better understanding of interstellar turbulence and its link to star formation. We present observations and structure analysis results for a…

Methanol, one of the simplest complex organic molecules in the Interstellar Medium (ISM), has been shown to be present and extended in cold environments such as starless cores. We aim at studying methanol emission across several starless…

In cold molecular clouds submillimetre emission lines are excited by the ambient radiation field. The pumping is dominated by the cosmic microwave background (CMB). It is usual in molecular line radiative transfer modelling to simply assume…

The recent X-ray and CO observations of RX J1713.7-3946 show that a significant fraction of the nonthermal X-ray emission of this unique supernova remnant associates, in one way or another, with a molecular cloud interacting with the west…

Our understanding of the physical and chemical structure of pre-stellar cores, the simplest star-forming sites, has significantly improved since the last IAU Symposium on Astrochemistry (South Korea, 1999). Research done over these years…

The cosmic abundance of hydrides depends critically on high-energy UV, X-ray, and particle irradiation. Here we study hydrides in star-forming regions where irradiation by the young stellar object can be substantial, and density and…

We present the detection analysis of a diffuse molecular cloud at z$_{abs}$=2.4636 towards the quasar SDSS J1513+0352(z$_{em}\,\simeq$ 2.68) observed with the X-shooter spectrograph(VLT). We measure very high column densities of atomic and…

New optical spectra of Ca II and Na I toward HD 72127AB provide additional evidence for both spatial and temporal variations in the complex interstellar absorption along the two sight lines; archival UV spectra yield information on the…

We examine the fine structure lines $^{3}P_{1}\to $$^{3}P_{0}$ (492 GHz) and $ ^{3}P_2\to $$^{3}P_1$ (809 GHz) of neutral atomic carbon as bulk molecular gas mass tracers and find that they can be good and on many occasions better than $…

Carbon-bearing molecules, particularly CO, have been widely used as tracers of molecular gas in the interstellar medium (ISM). In this work, we aim to study the properties of molecules in diffuse, cold environments, where CO tends to be…

Deuterium fractionation is known to enhance the [DCO+]/[HCO+] abundance ratio over the D/H elemental ratio of about 1e-5 in the cold and dense gas typically found in pre-stellar cores. We report the first detection and mapping of very…

Context. In dense clouds, hydrogenation reactions on icy dust grains are key in the formation of molecules, like formaldehyde, methanol, and complex organic molecules (COMs). These species form through the sequential hydrogenation of CO…

We review here the main direct or indirect ways to detect the possible presence of large amounts of cold molecular hydrogen in the outer parts of disk galaxies, an hypothesis that we have recently developed. Direct ways range from H2…

We found that in regions of high mass star formation the CS emission correlates well with the dust continuum emission and is therefore a good tracer of the total mass while the N$_2$H$^+$ distribution is frequently very different. This is…

This article presents the results of a study concerning interstellar molecules which are useful for the bookkeeping of the organic content of the universe and for providing a glimpse into prebiotic conditions on Earth and in other…