Results 31 to 40 of about 1,003,872 (220)

Electronically Excited States of Closed-Shell, Cyano-Functionalized Polycyclic Aromatic Hydrocarbon Anions

open access: yesChemistry, 2021
Few anions exhibit electronically excited states, and, if they do, the one or two possible excitations typically transpire beyond the visible spectrum into the near-infrared.
Taylor J. Santaloci, Ryan C. Fortenberry
doaj   +1 more source

Dust evolution, a global view: III. Core/mantle grains, organic nano-globules, comets and surface chemistry [PDF]

open access: yesRoyal Society Open Science, 2016
Within the framework of The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS), this work explores the surface processes and chemistry relating to core/mantle interstellar and cometary grain structures and their influence on the nature ...
A. P. Jones
doaj   +1 more source

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

open access: yes, 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   +5 more
core   +1 more source

Electronic spectroscopy of cold ions in a radio-frequency trap [PDF]

open access: yes, 2010
The low density of ions in mass spectrometers generally precludes direct absorption measurements. The spectrum of ions can nonetheless be obtained by using resonance two-color photofragmentation or multiphoton photofragmentation techniques.
Rudnev, Vitaly S.
core   +1 more source

Narrow absorption lines from intervening material in supernovae

open access: yesAstronomy & Astrophysics
Narrow interstellar absorption features in supernova (SN) spectra serve as valuable diagnostics for probing dust extinction and the presence of circumstellar or interstellar material.
Gutiérrez Claudia P.   +3 more
doaj   +1 more source

A search for interstellar absorptions towards Sgr dSph [PDF]

open access: yesAstronomy & Astrophysics, 2005
accepted by Astronomy & ...
Monai, S., Bonifacio, P., Sbordone, L.
openaire   +2 more sources

Photochemical Generation and Spectroscopic Characterization of Parent 3‐Iminooxetane and 3‐Oxazoline From 3‐Azidooxetane

open access: yesChemistry – A European Journal, EarlyView.
Two previously uncharacterized heterocyclic imines, 3‐iminooxetane and 3‐oxazoline, are generated simultaneously by irradiation of 3‐azidooxetane under matrix isolation conditions. The infrared spectra provide reference data for future gas‐phase studies and may facilitate their search in the interstellar medium.
Mika Maehara   +4 more
wiley   +1 more source

Abundance Ratios of OH/CO and HCO+/CO as Probes of the Cosmic-Ray Ionization Rate in Diffuse Clouds

open access: yesThe Astrophysical Journal, 2023
The cosmic-ray ionization rate (CRIR, ζ _2 ) is one of the key parameters controlling the formation and destruction of various molecules in molecular clouds. However, the current most commonly used CRIR tracers, such as ${{\rm{H}}}_{3}^{+}$ , OH ^+ , and
Gan Luo   +8 more
doaj   +1 more source

Creating a new paradigm for the local interstellar medium–A perspective

open access: yesFrontiers in Astronomy and Space Sciences, 2023
The interstellar medium close to the Sun called the local ISM (LISM) provides critical insights into physical processes and phenomena in the more distant interstellar medium in our Galaxy without the confusion of many complex structures in the sight ...
Jeffrey L. Linsky, Seth Redfield
doaj   +1 more source

VUV and mid‐UV photoabsorption cross sections of thin films of glycine and alanine: Application to their photochemistry in the solar system

open access: yesPhotochemistry and Photobiology, EarlyView.
Thin solid films of pure glycine or alanine (thicknesses ranging from 10 to 700 nm) were prepared on MgF2 windows using a vacuum sublimation/recondensation method. VUV‐UV spectroscopy of these films enabled us to characterize new absorption cross sections for glycine and alanine for VUV‐UV radiations between 120 and 300 nm.
Juliette Pastore   +6 more
wiley   +1 more source

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