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Related papers: On Ultrasmall Silicate Grains in the Diffuse Inter…

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Since their discovery, cosmic crystalline silicates have presented several challenges to understanding dust formation and evolution. The mid-infrared spectrum of IRAS 17495$-$2534, a highly obscured oxygen-rich asymptotic giant branch (AGB)…

Astrophysics · Physics 2009-11-13 Angela K. Speck , Alan G. Whittington , Josh B. Tartar

Recent space missions have provided information on the physical and chemical properties of interstellar grains such as the ratio $\beta$ of radiation pressure to gravity acting on the grains in addition to the composition, structure, and…

Astrophysics of Galaxies · Physics 2017-04-19 Hiroshi Kimura

We study the motion of dust grains into the Intergalactic Medium (IGM) around redshift z=3, to test the hypothesis that grains can efficiently pollute the gas with metals through sputtering. We use the results available in the literature…

Astrophysics · Physics 2009-11-10 Simone Bianchi , Andrea Ferrara

We report interstellar FeII and SiII column densities toward six translucent sight lines (A_V >~ 1) observed with the Space Telescope Imaging Spectrograph (STIS). The abundances were determined from the absorption of SiII] at 2335…

Silicate carbon stars show the 10 micron silicate emission, despite their carbon-rich photospheres. They are considered to have circumbinary or circum-companion disks, which serve as a reservoir of oxygen-rich material shed by mass loss in…

The composition and properties of interstellar silicate dust are not well understood. In X-rays, interstellar dust can be studied in detail by making use of the fine structure features in the Si K-edge. The features in the Si K-edge offer a…

Astrophysics of Galaxies · Physics 2019-07-10 S. T. Zeegers , E. Costantini , D. Rogantini , C. P. de Vries , H. Mutschke , P. Mohr , F. de Groot , A. G. G. M. Tielens

Recent observations with dust detectors on board the interplanetary spacecraft Ulysses and Galileo have recorded a substantial flux of large interstellar grains with radii between 0.25 and 2.0 mu entering the solar system from the local…

Astrophysics · Physics 2009-11-06 Adolf N. Witt , Randall K. Smith , Eli Dwek

We investigate the dust growth in oxygen-rich stellar outflows for a set of nine well-observed massive supergiants with optically thin dust shells. Models of the infrared emission from their circumstellar dust shells are compared to their…

Solar and Stellar Astrophysics · Physics 2021-01-04 Hans-Peter Gail , Akemi Tamanai , Annemarie Pucci , Ralf Dohmen

We announce the discovery of SST-Lup3-1, a very low mass star close to the brown dwarf boundary in Lupus III with a circum(sub)stellar disk, discovered by the `Cores to Disks' Spitzer Legacy Program from mid-, near-infrared and optical…

Analysis of all archival 5--14 micron spectra of field ultracool dwarfs from the Infrared Spectrograph on the Spitzer Space Telescope has shown that absorption by silicates in the 8--11 micron region is seen in most L-type (1300 K to 2200…

Solar and Stellar Astrophysics · Physics 2023-06-28 Genaro Suárez , Stanimir Metchev

Presolar silicon carbide (SiC) grains in meteoritic samples can help constrain circumstellar condensation processes and conditions in C-rich stars and core-collapse supernovae. This study presents our findings on eight presolar SiC grains…

Solar and Stellar Astrophysics · Physics 2021-05-31 Sheryl A. Singerling , Nan Liu , Larry R. Nittler , Conel M. O'D. Alexander , Rhonda M. Stroud

We study the extinction properties of the composite dust grains, consisting of host silicate spheroids and graphite as inclusions, using discrete dipole approximation (DDA). We calculate the extinction cross sections of the composite grains…

Solar and Stellar Astrophysics · Physics 2015-06-17 Nisha Katyal , Ranjan Gupta , D B Vaidya

Mid-Infrared (IR) silicate dust bands observed in heavily obscured active galactic nuclei (AGNs) include information on the mineralogical properties of silicate dust. We aim to investigate the mineralogical picture of the circumnuclear…

Astrophysics of Galaxies · Physics 2022-12-21 T. Tsuchikawa , H. Kaneda , S. Oyabu , T. Kokusho , H. Kobayashi , Y. Toba

The composite grain is made up of a host silicate spheroid and graphite inclusions. The extinction efficiencies of the composite spheroidal grains for three axial ratios are computed using the discrete dipole approximation (DDA). The…

Astrophysics · Physics 2009-06-23 D. B. Vaidya , Ranjan Gupta , T. P. Snow

Young stars are formed within dusty discs. The grains in the disc are originally of the same size as interstellar dust. Models predict that these grains will grow in size through coagulation. Observations of the silicate features at micron…

A wealth of data from the Herschel and Planck satellites and now from ALMA, revealing cold dust thermal emission, is available for astronomical environments ranging from interstellar clouds, cold clumps, circumstellar envelops, and…

While beta Pic is known to host silicates in ring-like structures, whether the properties of these silicate dust vary with stellocentric distance remains an open question. We re-analyze the beta Pictoris debris disk spectrum from the…

This paper examines the allowed amount of IG (intergalactic) dust, which is constrained by extinction and reddening of distant SNe and thermal history of IGM (intergalactic medium) affected by dust photoelectric heating. Based on the…

Astrophysics · Physics 2009-11-10 Akio K. Inoue , Hideyuki Kamaya

Whether ice in cold cosmic environments is physically separated from the silicate dust or mixed with individual silicate moieties is not known. However, different grain models give very different compositions and temperatures of grains. The…

Astrophysics of Galaxies · Physics 2020-08-26 Alexey Potapov , Jeroen Bouwman , Cornelia Jäger , Thomas Henning

The spectrum of any star viewed through a sufficient quantity of diffuse interstellar material reveals a number of absorption features collectively called diffuse interstellar bands (DIBs). The first DIBs were reported 90 years ago, and…

Astrophysics of Galaxies · Physics 2015-06-03 T. R. Geballe , F. Najarro , D. F. Figer , B. W. Schlegelmilch , D. de la Fuente
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