Results 61 to 70 of about 2,097,454 (229)
The Infrared Complex Refractive Index and Band Strengths of Coronene Thin Films
The Astrophysical JournalPolycyclic aromatic hydrocarbon (PAH) molecules have long been theorized to be present in a multitude of interstellar environments. The radio-frequency detections of specific cyanosubstituted PAH molecules in the Taurus Molecular Cloud have provided new ...
J. E. Roser, L. Jovanović, A. Ricca
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Cosmic Dust as a Prerequisite for the Formation of Complex Organic Molecules in Space?
The Astrophysical JournalIn cold, dense astrophysical environments dust grains are mixed with molecular ices. Chemistry in those dust/ice mixtures is determined by diffusion and reaction of molecules and radicals.
Alexey Potapov +4 more
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Dependence of Chemical Abundance on the Cosmic-Ray Ionization Rate in IC 348
The Astrophysical Journal, 2023 Ions (e.g., ${{\rm{H}}}_{3}^{+}$ , H _2 O ^+ ) have been used extensively to quantify the cosmic-ray ionization rate (CRIR) in diffuse sightlines. However, measurements of the CRIR in low-to-intermediate density gas environments are rare, especially when
Gan Luo +10 more
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Surface formation routes of interstellar molecules: hydrogenation reactions in simple ices
, 2011 It has been a long standing problem in astrochemistry to explain how molecules can form in a highly dilute environment such as the interstellar medium. In recent years it has become clear that not only ion/radical-molecule gas-phase reactions, but also ...
S. Ioppolo, H. Cuppen, H. Linnartz
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Astronomische Nachrichten, Volume 346, Issue 9, November 2025.ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin +10 more
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An Ultraviolet Study of CO Chemistry in the Magellanic Clouds
The Astronomical JournalHow does molecular cloud chemistry change with metallicity? In this work, we study the relation between molecular hydrogen (H _2 ) and carbon monoxide (CO) at 1/2 and 1/5 solar metallicity using ultraviolet absorption spectroscopy obtained as part of the
Kirill Tchernyshyov +2 more
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Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.Abstract The production, attenuation, and absorption of secondary cosmic rays (SCR) are influenced by atmospheric parameters such as air pressure and temperature. To reliably correlate SCR flux measurements with atmospheric ionization driven by energetic particle precipitation, these dependencies must be quantified.
A. Al‐Qaaod +11 more
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Physicochemical Constraints on the Abiotic Polymerization of Nucleotides Into RNA
Journal of Geophysical Research: Biogeosciences, Volume 130, Issue 11, November 2025.Abstract One of the key steps in the origin of life is the polymerization of nucleotides into nucleic acids like RNA. We have quantified the energetic impact of temperature, pressure, and composition on the polymerization of nucleotides into RNA using the Gibbs function. These Gibbs energies have been used to calculate the probability that a nucleotide
D. E. LaRowe, J. M. Dick
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The Astronomical JournalDeuterium fractionation, as studied through mono-deuterated methanol, is frequently used as a diagnostic tool to trace the physical conditions and chemical evolution of interstellar sources. This study investigates methanol deuteration in the disk around
Shaoshan Zeng +5 more
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Observations of the Onset of Complex Organic Molecule Formation in Interstellar Ices [PDF]
, 2020 E. Schunová +2 more
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