Results 11 to 20 of about 319,875 (285)

Evolution of grain size distribution with enhanced abundance of small carbonaceous grains in galactic environments [PDF]

Monthly Notices of the Royal Astronomical Society, 2022
ABSTRACT We propose an updated dust evolution model that focuses on the grain size distribution in a galaxy. We treat the galaxy as a one-zone object and include five main processes (stellar dust production, dust destruction in supernova shocks, grain growth by accretion and coagulation, and grain disruption by shattering). In this paper,
Hirashita, Hiroyuki
openaire   +3 more sources

Origin of isolated olivine grains in carbonaceous chondrites [PDF]

Meteoritics & Planetary Science, 2020
AbstractWe report microscopic, cathodoluminescence, chemical, and O isotopic measurements of FeO‐poor isolated olivine grains (IOG) in the carbonaceous chondrites Allende (CV3), Northwest Africa 5958 (C2‐ung), Northwest Africa 11086 (CM2‐an), and Allan Hills 77307 (CO3.0).
Jacquet, Emmanuel, Piralla, Maxime, Kersaho, Pauline, Marrocchi, Yves   +3 more
openaire   +4 more sources

Identification of Silicate and Carbonaceous Presolar Grains in the type 3 Enstatite Chondrites [PDF]

AIP Conference Proceedings, 2008
We surveyed presolar grains in primitive enstatite chondrites by isotopography using the HokuDai isotope microscope system. The mineral identification has been conducted by X‐ray analysis with scanning electron microscopy. The chemical compositions are determined for eight silicate and ten carbonaceous presolar grains.
Shingo Ebata, Hisayoshi Yurimoto, Takuma Suda, Takaya Nozawa, Akira Ohnishi, Kiyoshi Kato, Masayuki Y. Fujimoto, Toshitaka Kajino, Shigeru Kubono   +8 more
openaire   +4 more sources

Variations of organic functional chemistry in carbonaceous matter from the asteroid 162173 Ryugu [PDF]

Nature Communications
Primordial carbon delivered to the early earth by asteroids and meteorites provided a diverse source of extraterrestrial organics from pre-existing simple organic compounds, complex solar-irradiated macromolecules, and macromolecules from extended ...
Bradley De Gregorio, George D. Cody, Rhonda M. Stroud, A. L. David Kilcoyne, Scott Sandford, Corentin Le Guillou, Larry R. Nittler, Jens Barosch, Hikaru Yabuta, Zita Martins, Yoko Kebukawa, Taiga Okumura, Minako Hashiguchi, Shohei Yamashita, Yasuo Takeichi, Yoshio Takahashi, Daisuke Wakabayashi, Cécile Engrand, Laure Bejach, Lydie Bonal, Eric Quirico, Laurent Remusat, Jean Duprat, Maximilien Verdier-Paoletti, Smail Mostefaoui, Mutsumi Komatsu, Jérémie Mathurin, Alexandre Dazzi, Ariane Deniset-Besseau, Emmanuel Dartois, Yusuke Tamenori, Hiroki Suga, Gilles Montagnac, Kanami Kamide, Miho Shigenaka, Megumi Matsumoto, Yuma Enokido, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Tomohiro Usui, Masanao Abe, Tatsuaki Okada, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Ryuji Okazaki, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, Sei-ichiro Watanabe, Yuichi Tsuda   +58 more
doaj   +2 more sources

Energy partitioning in H₂ formation on interstellar carbonaceous grains. Insights from <i>ab initio</i> molecular dynamics simulations. [PDF]

Phys Chem Chem Phys
Altres ajuts: acords transformatius de la UABMolecular hydrogen (H) stands as the most abundant molecule within the interstellar medium (ISM), primarily originating from the coupling of two H atoms on the surfaces of dust grains.
Jubert L, Martínez-Bachs B, Pareras G, Rimola A.   +3 more
europepmc   +2 more sources

Elemental surface composition of comet 67P grains (Rosetta) and of carbonaceous chondrite meteorites - characterized by multivariate mass spectral data (COSIMA)

, 2017
International audienceDust grains have been collected near the comet 67P/Churyumov-Gerasimenko by the time-of-flight secondary ion mass spectrometer (TOF-SIMS) COSIMA on board of the Rosetta spacecraft. The measured mass spectra contain information about
Hilchenbach, Martin, Brandstätter, Franz, Hoffmann, Irene, Varmuza, Kurt, Kissel, Jochen, Modica, Paola, Paquette, John, Stenzel, Oliver, Fray, Nicolas, Filzmoser, Peter, Ferrière, Ludovic, Engrand, Cécile, Cottin, Hervé, Koeberl, Christian   +13 more
core   +7 more sources

Simulation of Infrared Spectra of Carbonaceous Grains [PDF]

The Astrophysical Journal, 1997
Random covalent network (RCN) theory is applied to describe the infrared spectroscopic properties of carbonaceous solids with compositions containing a mixture of aromatic, aliphatic, and diamond-like hydrocarbons. Application of this technique to carbonaceous dust is equivalent to the synthesis of solids whose structure and bonding satisfy ...
G. Dadswell, W. W. Duley
openaire   +1 more source

Luminescence from Small Carbonaceous Dust Grains [PDF]

Symposium - International Astronomical Union, 1990
A relationship exists between the amount of the ultraviolet (UV) extinction and the relative strength of the very broad structure (VBS) in the 500–600 nm wavelength region (5000–6000 Å) of the interstellar extinction curve. It is based on observations of OB stars distributed along the Milky Way.
Christian Friedemann, Hans-Georg Reimann
openaire   +1 more source

Radial distribution of the carbonaceous nano-grains in the protoplanetary disk around HD 169142 [PDF]

, 2022
HD 169142 is part of the class of (pre-)transitional protoplanetary disks showing multiple carbon nanodust spectroscopic signatures (aromatic, aliphatic) dominating the infrared spectrum.
Habart, Émilie, Marie Devinat, Anthony Jones, Ysard, Nathalie, Pantin, Éric, Émilie Habart, Lucas Labadie, Emmanuel Di Folco, Jones, Anthony, Di Folco, Emmanuel, Éric Pantin, Labadie, Lucas, Nathalie Ysard, Devinat, Marie   +13 more
core   +1 more source

Extended chronologies of aqueous alteration in the CM2 carbonaceous chondrites: evidence from carbonates in Queen Alexandra Range 93005 [PDF]

, 2012
The Antarctic CM2 carbonaceous chondrite QUE 93005 contains four compositionally distinct carbonates, namely breunnerite, calcite, dolomite and a Ca-poor dolomite. These carbonates can form monomineralic grains, or may be intergrown as bimineralic grains
Alexander, C., Lindgren, P., Lee, M., Sofe, M., Wang, J.   +4 more
core   +1 more source