Results 101 to 110 of about 2,128 (220)

Binding Energies of N-bearing Species on Interstellar Water Ice Mantles by Quantum Chemical Calculations

The Astrophysical Journal
Of the about 300 gas-phase molecular species so far detected in the interstellar medium (ISM), mostly via observations of their rotational lines, around 40% contain nitrogen (N) atoms.
Berta Martínez-Bachs, Stefano Ferrero, Cecilia Ceccarelli, Piero Ugliengo, Albert Rimola   +4 more
doaj   +1 more source

Molecular Evolution in Interstellar Clouds. I: Ion Chemistry in Dense Clouds [PDF]

Progress of Theoretical Physics, 1979
Molecular abundances are calculated time-dependently using a chemical scheme which is constructed to represent the evolutional feature of all molecules containing up to 2 heavy atoms (C, N, 0, S and Si) and consisted of the surface recombination of hydrogen on grains and2884gasphase reactions of 234 species. For the model adopted (nH=10'cm-•, T=30K, CH=
openaire   +1 more source

Optical interstellar lines in dark clouds. II. K i and ultraviolet sodium lines [PDF]

, 1974
New observations of the K i and ultraviolet Na i interstellar lines are presented for some stars embedded in dense clouds and for a few supergiants. The new observations of weak lines, which are essentially unaffected by the adopted velocity distribution
Cohen, Judith G.
core  

δ Orionis: Further temporal variability and evidence for small-scale structure in the interstellar medium [PDF]

, 2001
We report here the detection of both spatial and temporal variations in interstellar absorption in the line of sight to δ Orionis. First, we present new high-resolution (R≈110 000) observations of the interstellar D lines of Na i towards both δ Ori A and
Howarth, ID, Price, R.J., Crawford, Ian, Price, RJ, Crawford, IA, Howarth, I.D.   +5 more
core   +1 more source

Proposed Importance of HOCO Chemistry: Inefficient Formation of CO2 from CO and OH Reactions on Ice Dust

The Astrophysical Journal
With the advent of JWST ice observations, dedicated studies on the formation reactions of detected molecules are becoming increasingly important. One of the most interesting molecules in interstellar ice is CO _2 .
Atsuki Ishibashi, Germán Molpeceres, Hiroshi Hidaka, Yasuhiro Oba, Thanja Lamberts, Naoki Watanabe   +5 more
doaj   +1 more source

Photocleavage of Aliphatic C–C Bonds in the Interstellar Medium

The Astrophysical Journal
Ultraviolet (UV) processing in the interstellar medium (ISM) induces the dehydrogenation of hydrocarbons. Aliphatics, including alkanes, are present in different interstellar environments, being prevalently formed in evolved stars; thus, the ...
Guillermo Tajuelo-Castilla, Jesús I. Mendieta-Moreno, Mario Accolla, Jesús M. Sobrado, Sofia Canola, Pavel Jelínek, Gary J. Ellis, José Ángel Martín-Gago, Gonzalo Santoro   +8 more
doaj   +1 more source

Galactic Cosmic Ray Interaction with the Perseus Giant Molecular Cloud Using Geant4 Monte Carlo Simulation

Universe
Galactic cosmic rays (GCRs), composed of protons and atomic nuclei, are accelerated in sources such as supernova remnants and pulsar wind nebulae, reaching energies up to the PeV range.
Luan Torres, Luiz Augusto Stuani Pereira
doaj   +1 more source

Carbon monoxide in collapsing interstellar clouds

, 1975
This is the published version, also available here: http://dx.doi.org/10.1086/153665.Calculations are made for the energy loss rates, brightness temperatures, and line profiles of carbon monoxide in collapsing interstellar clouds.
Dalgarno, A., Chu, Shih-I, De Jong, T.
core   +1 more source

Playing with FIRE: A Galactic Feedback-halting Experiment Challenges Star Formation Rate Theories

The Astrophysical Journal
Stellar feedback influences the star formation rate (SFR) and the interstellar medium of galaxies in ways that are difficult to quantify numerically, because feedback is an essential ingredient of realistic simulations.
Shivan Khullar, Christopher D. Matzner, Norman Murray, Michael Y. Grudić, Dávid Guszejnov, Andrew Wetzel, Philip F. Hopkins   +6 more
doaj   +1 more source

PHOSPHORUS CHEMISTRY IN DENSE INTERSTELLAR CLOUDS

, 1991
I have used recent laboratory studies on the reactions of the phosphorus hydride ions, PH(n)+ (n = 0-4) to construct a new model of phosphorus chemistry in interstellar clouds.
Millar, TJ
core