Results 21 to 30 of about 789,439 (256)

FORMATION OF SMALL-SCALE STRUCTURES IN THEINTERSTELLAR MEDIUM

open access: yesOdessa Astronomical Publications, 2008
We consider formation of small scale structures in the process of interstellar cloud destruction by shock waves. We calculate statistical properties of HI column densities, optical depth and brightness temperature in 21 cm line.
E. E. Matvienko   +2 more
doaj   +1 more source

Learning from model grids: Tracers of the ionization fraction in the ISM [PDF]

open access: yesEPJ Web of Conferences, 2022
The ionization fraction in neutral interstellar clouds is a key physical parameter controlling multiple physical and chemical processes, and varying by orders of magnitude from the UV irradiated surface of the cloud to its cosmic-ray dominated central ...
Bron Emeric   +29 more
doaj   +1 more source

Interstellar hydrocarbons: degradation chemistry in diffuse clouds [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2022
ABSTRACT Observations of diffuse clouds showed that they contain a number of simple hydrocarbons [e.g. CH, C2H, (l- and c-)C3H2, and C4H] in abundances that may be difficult to understand on the basis of conventional gas-phase chemical models.
Zainab Awad, Serena Viti
openaire   +4 more sources

Turbulence in Interstellar Clouds [PDF]

open access: yesInternational Astronomical Union Colloquium, 1989
Above masses of the order of lOO M⊙, molecular clouds have masses and sizes which scale like those of self-gravitating polytropes bounded by an external pervading pressure. It is unlikely that this scaling is due to mere observational bias. But the physics underlying this behaviour is far from being understood.
openaire   +1 more source

Filtration of interstellar hydrogen in the two‐shock heliospheric interface: Inferences on the local interstellar cloud electron density [PDF]

open access: yes, 1998
The solar system is moving through the partially ionized local interstellar cloud (LIC). The ionized matter of the LIC interacts with the expanding solar wind forming the heliospheric interface.
V. Izmodenov   +5 more
semanticscholar   +1 more source

Radio Emission from a Young Supernova Remnant Interacting with an Interstellar Cloud: Magnetohydrodynamic Simulation with Relativistic Electrons [PDF]

open access: yes, 1998
We present two-dimensional MHD simulations of the evolution of a young Type Ia supernova remnant (SNR) during its interaction with an interstellar cloud of comparable size at impact. We include for the first time in such simulations explicit relativistic
Byung-Il. Jun, T. Jones
semanticscholar   +1 more source

Dissociative Recombination of Rotationally Cold OH+ and Its Implications for the Cosmic Ray Ionization Rate in Diffuse Clouds

open access: yesThe Astrophysical Journal Letters, 2023
Observations of OH ^+ are used to infer the interstellar cosmic ray ionization rate in diffuse atomic clouds, thereby constraining the propagation of cosmic rays through and the shielding by interstellar clouds, as well as the low energy cosmic ray ...
Ábel Kálosi   +14 more
doaj   +1 more source

Complex Reactive Acids from Methanol and Carbon Dioxide Ice: Glycolic Acid (HOCH2COOH) and Carbonic Acid Monomethyl Ester (CH3OCOOH)

open access: yesThe Astrophysical Journal, 2023
The formation of complex organic molecules by simulated secondary electrons generated in the track of galactic cosmic rays was investigated in interstellar ice analogs composed of methanol and carbon dioxide.
Joshua H. Marks   +5 more
doaj   +1 more source

CLOUD STRUCTURE OF INTERSTELLAR MATTER. OBSERVATIONAL PARAMETERS

open access: yesOdessa Astronomical Publications, 2017
Parameters of 7600 HI clouds were determined on the base of HI RATAN-600 Survey in the second and third quadrants of galactic longitudes. The spectra of cloud linear diameters, HI densities and masses are obtained first for such huge population of clouds.
I. V. Gosachinskij, V. V. Morozova
doaj   +1 more source

Discovery of the Elusive Carbonic Acid (HOCOOH) in Space

open access: yesThe Astrophysical Journal, 2023
A quarter century after the detection of the last interstellar carboxylic acid, acetic acid (CH _3 COOH), we report the discovery of a new one, the cis-trans form of carbonic acid (HOCOOH), toward the Galactic center molecular cloud G+0.693–0.027. HOCOOH
Miguel Sanz-Novo   +14 more
doaj   +1 more source

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