February 5, 2008 Two sets of data show that small interstellar grains captured in interstellar magnetic fields, → BIS, draped over the heliosphere appear to polarize the light of nearby stars. The polarizing grains couple to → BIS, while larger grains couple to the cloud velocity. The maximum polarization direction, Pmax, is offset in ecliptic longitude by ∆λ ∼ +35 from the upwind direction, an...

The observation and theory of UV{excitation of molecular clouds (i.e., photodissociation regions) and the shock-excitation of molecular clouds is reviewed, with particular emphasis placed on the emission from molecular hydrogen. Recent advances in near{IR instrumentation have engendered new observations which are challenging our theoretical understanding of these fundamental physical processes....

This work presents the results of a theoretical study that analyzed possibility nucleobases to form in interstellar medium, Horsehead nebula, which is region considered an archetype molecular cloud. Performing Meudon PDR code, reactions nitrogen bases formation from formamide, precursor compound identified several environment, where simulated. The model showed at least cytosine and uracil prese...

Context. Studying the composition of dust in the interstellar medium (ISM) is crucial for understanding the cycle of dust in our galaxy. Aims. The mid-infrared spectral signature of amorphous silicates, the most abundant dust species in the ISM, is studied in different lines-of-sight through the Galactic plane, thus probing different conditions in the ISM. Methods. We have analysed ten spectra ...

The Ulysses spacecraft has been orbiting the Sun on a highly inclined ellipse almost perpendicular to the ecliptic plane (inclination 79◦, perihelion distance 1.3 AU, aphelion distance 5.4 AU) since it encountered Jupiter in 1992. The in-situ dust detector on board continuously measured interstellar dust grains with masses up to 10−13 kg, penetrating deep into the solar system. The flow directi...

Context. Studying the composition of dust in the interstellar medium (ISM) is crucial for understanding the cycle of dust in our galaxy. Aims. The mid-infrared spectral signature of amorphous silicates, the most abundant dust species in the ISM, is studied in different lines-of-sight through the Galactic plane, thus probing different conditions in the ISM. Methods. We have analysed ten spectra ...

Polycyclic aromatic hydrocarbons and related species have been suggested to play a key role in the astrochemical evolution of the interstellar medium, but the formation mechanism of even their simplest building block--the aromatic benzene molecule--has remained elusive for decades. Here we demonstrate in crossed molecular beam experiments combined with electronic structure and statistical calcu...

The interaction of the heliosphere with interstellar clouds has attracted interest since the late 1920’s, both with a view to explaining apparent quasi-periodic climate “catastrophes” as well as periodic mass extinctions. Until recently, however, models describing the solar wind local interstellar medium (LISM) interaction self-consistently had not been developed. Here, we describe the results ...

The interaction of the heliosphere with interstellar clouds has attracted interest since the late 1920's, both with a view to explaining apparent quasi-periodic climate " catastrophes " as well as periodic mass extinctions. Until recently, however, models describing the solar wind-local interstellar medium (LISM) interaction self-consistently had not been developed. Here, we describe the result...

The interaction of dust grains originating from the local interstellar cloud with the environment inside the heliosphere is investigated. As a consequence of this interaction the spatial distribution of interstellar dust grains changes with time. Since dust grains are charged in the interplanetary plasma and radiation environment, the interaction of small grains with the heliosphere is dominate...