Results 21 to 30 of about 137,092 (301)

Chiral and Molecular Recognition through Protonation between Aromatic Amino Acids and Tripeptides Probed by Collision-Activated Dissociation in the Gas Phase

open access: yesMolecules, 2018
Chiral and molecular recognition through protonation was investigated through the collision-activated dissociation (CAD) of protonated noncovalent complexes of aromatic amino acid enantiomers with l-alanine- and l-serine-containing tripeptides using a ...
Akimasa Fujihara   +4 more
doaj   +1 more source

Outer-Galaxy molecular clouds [PDF]

open access: yesSymposium - International Astronomical Union, 1985
Since our original report of CO emission from outside the solar circle in the first quadrant (Kutner and Mead, 1981) we have extended the observations in two ways: (1) We have improved latitude and longitude coverage. Preliminary results on the latitude distribution were reported by Kutner (1983).
Marc L. Kutner, Kathryn N. Mead
openaire   +1 more source

The simulation of molecular clouds formation in the Milky Way [PDF]

open access: yes, 2012
Using 3D hydrodynamic calculations we simulate formation of molecular clouds in the Galaxy. The simulations take into account molecular hydrogen chemical kinetics, cooling and heating processes.
A. M. Sobolev   +88 more
core   +1 more source

Molecular cloud evolution – VI. Measuring cloud ages [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2018
In previous contributions, we have presented an analytical model describing the evolution of molecular clouds (MCs) undergoing hierarchical gravitational contraction. The cloud's evolution is characterized by an initial increase in its mass, density, and star formation rate (SFR) and efficiency (SFE) as it contracts, followed by a decrease of these ...
Vázquez-Semadeni, Enrique   +3 more
openaire   +2 more sources

Kinematic Distances to Molecular Clouds identified in the Galactic Ring Survey [PDF]

open access: yes, 2009
Kinematic distances to 750 molecular clouds identified in the 13CO J=1-0 Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey (BU-FCRAO GRS) are derived assuming the Clemens rotation curve of the Galaxy.
Alexis Johnson   +43 more
core   +4 more sources

Submillimeter and Far-Infrared Polarimetric Observations of Magnetic Fields in Star-Forming Regions

open access: yesFrontiers in Astronomy and Space Sciences, 2019
Observations of star-forming regions by the current and upcoming generation of submillimeter polarimeters will shed new light on the evolution of magnetic fields over the cloud-to-core size scales involved in the early stages of the star formation ...
Kate Pattle, Laura Fissel
doaj   +1 more source

Fragmentation in molecular clouds [PDF]

open access: yesSymposium - International Astronomical Union, 1991
B209. Fragments are detected in the outer parts of the B209 molecular cloud in a region of density 1000 cm−3 using 12CO, 13CO, H2CO, IRAS 60 and 100 μm images, discernable as velocity components, and have characteristics: <Rfragment>∼ 0.4 pc; <Mfragment>∼ 2 M⊙; <MVRfragment>∼ 1.6 M⊙ km/s pc; Tgas ∼ 11 K; Tdust> ∼ 16 K??. The system
Frank O. Clark   +2 more
openaire   +1 more source

Evidence for a Molecular Cloud Origin for Gamma-Ray Bursts: Implications for the Nature of Star Formation in the Universe [PDF]

open access: yes, 2001
It appears that the majority of rapidly-, well-localized gamma-ray bursts with undetected, or dark, optical afterglows, or `dark bursts' for short, occur in clouds of size R > 10L_{49}^{1/2} pc and mass M > 3x10^5L_{49} M_{sun}, where L is the isotropic ...
Dal Fiume D.   +7 more
core   +2 more sources

OBSERVATIONS OF NON TYPICAL MASERS AT THE RT-22 RADIO TELESCOPE IN 2004–2013

open access: yesRadio Physics and Radio Astronomy, 2017
Purpose: Some peculiarities of emission of Class I methanol masers on the 80–71A+ transition at 95 GHz in sources closely associated with protostar-forming regions and in supernova remnants are studied.
V. M. Shulga   +6 more
doaj   +1 more source

Galaxy chemical evolution models: The role of molecular gas formation [PDF]

open access: yes, 2017
In our classical grid of multiphase chemical evolution models, star formation in the disc occurs in two steps: first, molecular gas forms, and then stars are created by cloud-cloud collisions or interactions of massive stars with the surrounding ...
Ascasibar, Yago   +4 more
core   +2 more sources

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