We present the mass distribution of interstellar grains measured in situ by the Galileo and Ulysses spaceprobes as cumulative flux. The derived in situ mass distribution per logarithmic size interval is compared to the distribution determined by fitting extinction measurements. Large grains measured in situ contribute significantly to the overall mass of dust in the local interstellar cloud. Th...

We have studied gas-grain chemical models of interstellar clouds to search for nonlinear dynamical evolution. A prescription is given producing oscillatory solutions when a bistable solution exists in the gas-phase chemistry and we demonstrate existence limit cycle relaxation oscillation solutions. As autocatalytic processes underlying these are common all chemistry, occurrence should be widesp...

We have compared the B−V colour excess, E(B–V), obtained for a sample of five optically visible massive YSOs both from diffuse interstellar bands (DIBs) in their spectra and from their optical continuum slopes. Our targets are HD 200775, BD+40o4124, MWC 1080, MWC 297 and MWC 349A. First, E(B–V) towards each of the targets is derived by dereddening the observed continua to match those of B-type ...

The formation of molecular hydrogen in the interstellar medium takes place on the surfaces of dust grains. Hydrogen molecules play a role in gasphase reactions that produce other molecules, some of which serve as coolants during gravitational collapse and star formation. Thus, the evaluation of the production rate of hydrogen molecules and its dependence on the physical conditions in the cloud ...

Context. V838 Mon erupted at the beginning of 2002 becoming an extremely luminous star with L=106 L⊙. The outburst was followed by the most spectacular light echo that revealed that the star is immersed in a diffuse and dusty medium, plausibly interstellar in nature. Low angular resolution observations of the star and its closest vicinity in the lowest CO rotational transitions revealed a molec...

We have used integral field echelle spectroscopy with the DensePak fiber-optic array on the KPNO WIYN telescope to observe the central 27 × 43 of the globular cluster M92 in the Na I D wavelength region at a spatial resolution of 4. Two interstellar Na I absorption components are evident in the spectra at LSR velocities of 0 km s (Cloud 1) and -19 km s (Cloud 2). Substantial strength variations...

Aims. Interstellar molecules form early in the evolutionary sequence of interstellar material that eventually forms stars and planets. To understand this sequence, it is important to characterize chemical composition its first steps. Methods. In paper, we present result a 2 3 mm survey five cold clumps identified by Planck mission. We carried out radiative transfer analysis on detected lines or...

A polarization image, with 0.6" pixel scale, of the molecular hydrogen v=1{0 S(1) line at 2.1218 m in the core of the Orion Molecular Cloud One, is presented. The line emission is highly clumped, with a prominent lamentary structure protruding to the NW, away from the source of the out ow. There are two main characteristics of the line polarization; a region of aligned vectors over the the mole...

We describe quantitatively the neutral hydrogen (HI) and dust content of the interstellar medium (ISM) in the Small Magellanic Cloud (SMC), using the spatial power spectrum. The velocity modification of the HI density power spectrum is investigated and discussed.