Excellent HST/GHRS spectra of interstellar hydrogen and deuterium Lyman-absorption toward nearby stars allow us to identify systematic errors that have plagued earlier work and to measure accurate values of the D/H ratio in local interstellar gas. Analysis of 12 sightlines through the Local Interstellar Cloud leads to a mean value of D/H = (1:50 0:10) 10 ?5 with all data points lying within 1 o...

Molecular clouds are expected to emit non-thermal radiation due to cosmic ray interactions in the dense magnetized gas. Such emission is amplified if a cloud is located close to an accelerator of cosmic rays and if energetic particles can leave the accelerator site and diffusively reach the cloud. We consider here the situation in which a molecular cloud is located in the proximity of a superno...

In this Ðrst in a series of papers, we develop a methodology for constructing three-dimensional models of the local interstellar cloud (LIC) and adjacent warm clouds in the local interstellar medium (LISM). Our models are based on the column density of neutral hydrogen gas inferred primarily from mea(NH I surements of the deuterium column density toward nearby stars obtained from the analysis o...

Four different data sets pertaining to the neutral atom environment at 1 AU are presented and discussed. These data sets include neutral solar wind and interstellar neutral atom data from IMAGE/LENA, energetic hydrogen atom data from SOHO/HSTOF and plasma wave data from the magnetometer on ISEE-3. Surprisingly, these data sets are centered between 262◦ and 292◦ ecliptic longitude, ∼10◦-40◦ from...

Molecular clouds in the interstellar medium suffer gravitational instabilities that lead to the formation of one or multiple stars. A recently formed star inside a cold cloud communicates its gravitational force to the surrounding environment and soon an accretion flow falling into the star develops. After their formation, all stars soon eject a wind of gas that interacts with the external accr...

The ESA meteoroid model predicts impacts of meteoroids in the mass range between 10 to 10 g on spacecraft surfaces. It covers heliocentric distances from 0.3 to 20 AU. Measurements of the dust detector on board the highly successful joint ESA/NASA mission Ulysses have shown, that the flux of meteoroids with masses between 10 and 10 g is, at least in the outer Solar System, dominated by interste...

A knowledge of the recombination time on the grain surfaces has been a major obstacle in deciding the production rate of molecular hydrogen and other molecules in the interstellar medium. We present a numerical study to compute this time for molecular hydrogen for various cloud and grain parameters. We also find the time dependence, particularly when a grain is freshly injected into the system....

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...

ABSTRACT We study the relationship between scale height of molecular gas disc and turbulent velocity dispersion interstellar medium within a simulation Milky Way-like galaxy in moving-mesh code arepo. find that vertical distribution can be described by Gaussian function with uniform ∼50 pc. investigate whether this is consistent state hydrostatic balance gravity pressure. prediction using total...