Results 81 to 90 of about 110,395 (224)
High Velocity Rain: The Terminal Velocity of Model of Galactic Infall [PDF]
A model is proposed for determining the distances to falling interstellar clouds in the galactic halo by measuring the cloud velocity and column density and assuming a model for the vertical density distribution of the Galactic interstellar medium. It is shown that falling clouds with $N(H I) < \sim 10^{19} cm^{-2}$ may be decelerated to a terminal ...
arxiv +1 more source
Interstellar H2 toward HD 37903
We present an analysis of interstellar H2 toward HD 37903, which is a hot, B 1.5 V star located in the NGC 2023 reflection nebula. Meyer et al. (2001) have used a rich spectrum of vibrationally excited H2 observed by the HST to calculate a model of the ...
Abgrall+14 more
core +1 more source
A Reanalysis of the Carbon Abundance in the Translucent Cloud toward HD 24534 [PDF]
We have reanalyzed the Goddard High Resolution Spectrograph data set presented by Snow et al. which contains the interstellar intersystem C II] 2325A line through the translucent cloud toward HD 24534 (X Persei). In contrast to the results of Snow et al.,
David M. Meyer+4 more
core +2 more sources
Cyanides, ranging from three carbon atoms to polycyclic aromatic hydrocarbons, and alkenyl compounds are abundant in the interstellar medium. Aminoacrylonitrile (3-Amino-2-propenenitrile, H _2 N–CH=CH–C≡N), an alkenyl cyanide, thus represents a promising
D. Alberton+7 more
doaj +1 more source
Properties of interstellar wind leading to shape morphology of the dust surrounding HD 61005 [PDF]
A structure formed by dust particles ejected from the debris ring around HD 61005 is observed in the scattered light. The main aim here is to constrain interstellar wind parameters that lead to shape morphology in the vicinity of HD 61005 using currently available observational data for the debris ring.
arxiv +1 more source
The H3+ molecular ion plays a fundamental role in interstellar chemistry, as it initiates a network of chemical reactions that produce many interstellar molecules. In dense clouds, the H3+ abundance is understood using a simple chemical model, from which
A. Al-Khalili+40 more
core +1 more source
Formation of Methanol via Fischer‐Tropsch Catalysis by Cosmic Iron Sulphide
Periodic quantum mechanical simulations evidence the potentiality to synthesise methanol through a Fischer‐Tropsch mechanism in different astrophysical environments facilitated by the catalytic properties of cosmic FeS grains, which are enhanced by the presence of naturally‐occurring point surface defects.
Berta Martinez‐Bachs+3 more
wiley +1 more source
The Effect of an Inert Solid Reservoir on Molecular Abundances in Dense Interstellar Clouds
The question, what is the role of freeze-out of chemical species in determining the molecular abundances in the interstellar gas is a matter of debate.
Kalvāns Juris, Shmeld Ivar
doaj +1 more source
Abstract We analyzed the methanol extracts of six pristine specimens of the Tagish Lake meteorite (TL1, TL4, TL5A, TL6, TL7, and TL10a) and heated and unheated samples of Allende using high‐performance liquid chromatography coupled with high‐resolution, accurate mass–mass spectrometry (HPLC‐HRAM‐MS).
N. Randazzo+5 more
wiley +1 more source
Atomic and Molecular Phases of the Interstellar Medium [PDF]
This review covers four current questions in the behavior of the atomic and molecular interstellar medium. These include whether the atomic gas originates primarily in cold streams or hot flows onto galaxies; what the filling factor of cold gas actually is in galactic regions observationally determined to be completely molecular; whether molecular ...
arxiv +1 more source