We model the intermediate time evolution of a “jetted” gamma-ray burst by two blobs of matter colliding with the interstellar medium. We follow the hydrodynamical evolution of this system numerically and calculate the bremsstrahlung and synchrotron images of the remnant. We find that for a burst energy of 10 erg the remnant becomes spherical after ∼ 5000 years when it collects ∼ 50M⊙ of interst...

We have observed the 492 GHz ground-state line of atomic carbon in the edge-on ionization fronts in M17 and .s1~0. y.te find that, contrary to expectation, the C I emission peaks farther into the molecular cloud from t~e Iomza~IO~ fro~t than does the CO. In fact the peak C I abundance in M17 occurs more than 60 mag of visual extmctton mto the cloud from the ionization front. Calculations of the...

A model, based on different observations of the local interstellar medium, indicates the presence of a very close interstellar cloud in front of the Scorpius-Ophiuchus association (almost in the direction of the galactic center) approaching the solar system from a distance of about 0.03 pc at a velocity of about 15-20 km s. These observations are as follows: 1. The strong gradient of the hydrog...

Almost all interstellar objects contain inherent inhomogeneity. The inhomogeneity can manifest in many different ways, such as the uneven matter distribution in a molecular cloud, or the tangled magnetic field distribution in a Bok globule. The dynamics of interstellar objects is thus often governed by the interaction between astrophysical flows or shocks such as supernova blast waves with inho...

The cosmic-ray proton and helium spectra from 0.2 GeV nucleon~1 to about 200 GeV nucleon~1 have been measured with the balloon-borne experiment Isotope Matter-Antimatter Experiment (IMAX) launched from Lynn Lake, Manitoba, Canada, in 1992. IMAX was designed to search for antiprotons and light isotopes using a superconducting magnet spectrometer together with scintillators, a time-ofÑight system...

A new calculation of nuclear enhancement factor, used in estimation of Galactic diffuse gamma-ray flux from proton-proton interaction in order to take account of heavy nuclei included in cosmic-rays and interstellar matter, is presented by use of a Monte Carlo simulator, DPMJET-3. A new value of 1.8–2.0 in the energy range of 6–1000 GeV/nucleon, slightly increasing with kinetic energy of projec...

We report the detection of the heavy elements Ca, Mg, Fe in the atmosphere of the variable DA white dwarf G29-38. The abundance of Ca can be understood only if accretion from interstellar matter is going on currently at a high rate. This lends support also to the interpretation of the observed infrared excess as due to heated circumstellar material, from which the accretion onto the star takes ...

Aromaticmolecules (PAHs or others) are considered to be an abundant component of the Interstellar Matter. However, their formation process remains a problem since a high production rate is required in order to balance the destruction mainly caused by shocks in the Interstellar Medium. We propose that catalytic reactions, based on organometallic chemistry could contribute efficiently to the form...

We propose a new mechanism to explain the radio Arc and threads in the Galactic Center by current sheets produced by local magnetic shears due to interaction of a moving cloud and the vertical field based on three-dimensional magnetohydrodynamical simulations. Magnetic reconnetion and acceleration of cosmic-ray electrons in the current sheet will result in high contrast of radio emissivity insi...

Interstellar material surrounding an extrasolar planetary system interacts with the stellar wind to form the stellar astrosphere, and regulates the properties of the interplanetary medium and cosmic ray fluxes throughout the system. Advanced life and civilization developed on Earth during the time interval when the Sun was immersed in the vacuum of the Local Bubble and the heliosphere was large...