Related papers: The Photon Dominated Region in the IC 348 molecula…

The accepted explanation of the observed dichotomy of two orders of magnitude between in situ measurements of electron density in HII regions, derived from emission line ratios, and average measurements based on integrated emission measure,…

Molecular line observations may serve as diagnostics of the degree to which the number density of cosmic ray protons, having energies of 10s to 100s of MeVs each, is enhanced in starburst galaxies and galaxies with active nuclei. Results,…

The Galactic Cold Cores (GCC) project has made Herschel observations of interstellar clouds where Planck detected compact sources of cold dust emission. Our aim is to characterise the structure of the clumps and their parent clouds. We also…

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial…

Infrared dark clouds (IRDCs) are dense, molecular structures in the interstellar medium that can harbour sites of high-mass star formation. IRDCs contain supersonic turbulence, which is expected to generate shocks that locally heat pockets…

We present an analysis of the region IRAS 08589-4714 with the aim of characterizing the molecular environment. We observed the CO(3-2), ^{13}CO(3-2), C^{18}O(3-2), HCO+(3-2), and HCN(3-2) molecular lines in a region of 150" x 150", centered…

We have performed C$^{18}$O ($J$=1--0) mapping observations of a $20'\times20'$ area of the OMC-1 region in the Orion A cloud. We identified 65 C$^{18}$O cores, which have mean radius, velocity width in FWHM, and LTE mass of 0.18$\pm$0.03…

We aim to give a full description of the distribution and location of dense molecular clouds in the giant molecular cloud complex W43. It has previously been identified as one of the most massive star-forming regions in our Galaxy. To trace…

We analyze the gamma-ray emission from 9 high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope (LAT) between 250 MeV and 10 GeV. Observations of gamma-rays allow us to probe the density and spectrum of cosmic…

We present molecular line observations made with the IRAM 30-m telescope of the immediate surroundings of a sample of 11 candidate high-mass protostars. These observations are part of an effort to clarify the evolutionary status of a set of…

Young stars form in molecular cores, which are dense condensations within molecular clouds. We have searched for molecular cores traced by $^{13}$CO $J=1\to 0$ emission in the Taurus molecular cloud and studied their properties. Our data…

We present a formalism for continuum and line emission from random clumpy media together with its application to problems of current interest, including CO spectral lines from ensembles of clouds and radio emission from HII regions,…

CO isotopologue transitions are routinely observed in molecular clouds to probe the column density of the gas, the elemental ratios of carbon and oxygen, and to trace the kinematics of the environment. We aim at estimating the abundances,…

We present spectral line images of [CI] 809 GHz, CO J=1-0 115 GHz and HI 1.4 GHz line emission, and calculate the corresponding C, CO and H column densities, for a sinuous, quiescent Giant Molecular Cloud about 5 kpc distant along the…

Column density (N) PDFs serve as a powerful tool to characterize the physical processes that influence the structure of molecular clouds. Star-forming clouds can best be characterized by lognormal PDFs for the lower N range and a power-law…

Molecular globules and pillars are spectacular features, found only in the interface region between a molecular cloud and an HII-region. Impacting Far-ultraviolet (FUV) radiation creates photon dominated regions (PDRs) on their surfaces…

We have obtained column density maps for an unbiased sample of 120 molecular clouds in the third quadrant of the Milky Way mid-plane (b$\le |5|^{\circ}$) within the galactic longitude range from 195$^{\circ}$ to 225$^{\circ}$, using the…

We have constructed three-dimensional models for the equilibrium abundance of molecular hydrogen within diffuse interstellar clouds of arbitrary geometry that are illuminated by ultraviolet radiation. The position-dependent photo-…

We present a coarsely-sampled map of the region |l|<=2 degrees, |b|<=0.1 degrees in the 492 GHz 3P1-->3P0 fine structure transition of neutral carbon, observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). The…

We calculate theoretical population ratios of the ground fine-structure levels of some atoms/ions which typically exhibit UV lines in the spectra of QSO absorbers redward the Ly-alpha forest: C0, C+, O0, Si+ and Fe+. The most reliable…