Results 71 to 80 of about 1,259 (182)
The Definitive Abundance of Interstellar Oxygen
The Astrophysical Journal, 1998 Using the Goddard High Resolution Spectrograph (GHRS) onboard HST, we have obtained high S/N echelle observations of the weak interstellar O I 1356 A absorption toward the stars Gamma Cas, Epsilon Per, Delta Ori, Epsilon Ori, 15 Mon, Tau CMa, and Gamma Ara. In combination with previous GHRS measurements in six other sightlines (Zeta Per, Xi Per, Lambda
Meyer, David M. +2 more
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The isotopic abundances of interstellar oxygen
The Astrophysical Journal, 1981 The relative abundance of /sup 17/O and /sup 18/O is found to be remarkably uniform in the giant molecular clouds of our Galaxy, varying by less than approx.5% between the galactic center and the most distant (approx.12 kpc) sources. This uniformity is seen to reflect the close similarity in the galactic distributions of the processes by which these ...
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Carbon Isotope Fractionation of Complex Organic Molecules in Star-forming Cores
The Astrophysical JournalRecent high-resolution and sensitivity Atacama Large Millimeter/submillimeter Array observations have unveiled the carbon isotope ratios ( ^12 C/ ^13 C) of complex organic molecules (COMs) in a low-mass protostellar source. To understand the ^12 C/ ^13 C
Ryota Ichimura +2 more
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Chemistry of NH2CH2CH2OH and Its Related Species in the Interstellar Medium
The Astrophysical Journal Supplement SeriesEthanolamine (NH _2 CH _2 CH _2 OH) can form not only glycine directly under the conditions of proposed Archean alkaline hydrothermal vents, a possible environment for the origin of life, but also the polar hydrophilic head of phosphatidylethanolamine ...
Guoming Zhao +12 more
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Abundances of Chemical Elements in Open Star Clusters as Indicators of their Nature
Open Astronomy, 2015 Applying a compilled catalog, we find that the relative abundances of α-elements in open clusters and in field stars of the thin disk of the Galaxy show different dependencies on metallicity, age and parameters of their Galactic orbits.
Marsakov V. A. +3 more
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Interstellar abundances of oxygen and nitrogen
The Astrophysical Journal, 1983 Neutral nitrogen and oxygen column densities or limits are derived for 53 path lengths through the diffuse interstellar medium and compared with column densities of neutral hydrogen. For neither N nor O is a systematic increase of depletion found as reddening increases.
D. G. York +6 more
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Interstellar abundances : gas and dust.
The Astrophysical Journal, 1974 Data on abundances of interstellar atoms, ions and molecules in front of zeta Oph are assembled and analyzed. The gas-phase abundances of at least 11 heavy elements are significantly lower, relative to hydrogen, than in the solar system. The abundance deficiencies of certain elements correlate with the temperatures derived theoretically for particle ...
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Are Stars Really Ingesting Their Planets? Examining an Alternative Explanation
The Astrophysical JournalNumerous stars exhibit surprisingly large variations in their refractory element abundances, often interpreted as signatures of planetary ingestion events.
Nadine H. Soliman, Philip F. Hopkins
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Ionization Structure and Metal Enrichment of the Galactic Center Minispiral Observed with JWST
The Astronomical JournalSagittarius A* (Sgr A*) is the nearest quiescent supermassive black hole, and its proximity offers a unique opportunity to study its surrounding fuel supply.
Nicole M. Ford +13 more
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Rapid Chemical Enrichment by Intermittent Star Formation in GN-z11
The Astrophysical Journal LettersWe interpret the peculiar supersolar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 ( z = 10.6) using our state-of-the-art chemical evolution models.
Chiaki Kobayashi, Andrea Ferrara
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