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A model of spheroidal particles is used to calculate the steady-state temperature of dust grains immersed in the interstellar radiation field. It is found that the temperature of non-spherical grains with the aspect ratios a/b <= 2 deviates…

Astrophysics · Physics 2007-05-23 N. V. Voshchinnikov , D. A. Semenov , Th. Henning

Context. High-resolution X-ray spectroscopy offers a powerful tool to investigate the physical and chemical properties of dust grains, especially through the analysis of absorption edges of elements such as oxygen, magnesium, silicon, and…

Astrophysics of Galaxies · Physics 2026-04-28 B. Vaia , S. T. Zeegers , I. Abril-Cabezas , E. Costantini

In this paper we study the effects of inclusions and porosities on the emission properties of silicate grains and compare the model curves with the observed infrared emission from circumstellar dust. We calculate the absorption efficiency…

Solar and Stellar Astrophysics · Physics 2015-03-17 D. B. Vaidya , Ranjan Gupta

We review the current knowledge and understanding of the interstellar medium of our galaxy. We first present each of the three basic constituents - ordinary matter, cosmic rays, and magnetic fields - of the interstellar medium, laying…

Astrophysics · Physics 2008-11-26 Katia M. Ferriere

We consider the depletion of elements from the interstellar gas onto a population of very small dust grains. Adopting a grain model in which of order 4% of the cosmic C abundance is in grains with radii <= 10 Angstroms, we find that the…

Astrophysics · Physics 2009-10-31 Joseph C. Weingartner , Bruce T. Draine

A simple analytical model of intergranular normal stresses is proposed for a general elastic polycrystalline material with arbitrary shaped and randomly oriented grains under uniform loading. The model provides algebraic expressions for the…

Materials Science · Physics 2023-04-21 Samir El Shawish , Timon Mede

The interstellar medium has a highly filamentary and hierarchical structure, which may play a significant role in star formation. A systematical study on the large-scale filaments towards their physical parameters, distribution, structures…

Astrophysics of Galaxies · Physics 2022-01-06 Yifei Ge , Ke Wang

A gamma-ray line production calculation in astrophysics depends on i) the composition and energy source spectrum of the energetic particles, ii) the propagation model, and iii) the nuclear cross sections. The main difficulty for model…

Astrophysics · Physics 2009-11-07 E. Parizot , R. Lehoucq

The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The…

Astrophysics · Physics 2009-11-07 S. Wolf

Interstellar dust grains are often aligned. If the grain alignment direction varies along the line of sight, the thermal emission becomes circularly-polarized. In the diffuse interstellar medium, the circular polarization at far-infrared…

Astrophysics of Galaxies · Physics 2025-04-07 B. T. Draine

Most planetary systems are formed within stellar clusters, and these environments can shape their properties. This paper considers scattering encounters between solar systems and passing cluster members, and calculates the corresponding…

Earth and Planetary Astrophysics · Physics 2015-06-23 Gongjie Li , Fred C. Adams

We calculate the absorption efficiency of the composite grains, made up of host silicate spheroids and inclusions of ices/graphites/or voids, in the spectral region $7.0-14.0\mu$m The absorption efficiencies of the composite spheroidal…

Astrophysics of Galaxies · Physics 2009-04-03 Deepak B. Vaidya , Ranjan Gupta

We show that space-based telescopes such as the proposed Terrestrial Planet Finder Coronagraph will be able to detect the light scattered by the interstellar grains along lines of sight passing near stars in our Galaxy. The relative flux of…

Astrophysics · Physics 2009-11-13 N. J. Turner , K. Grogan , J. B. Breckinridge

Extremely elongated, conducting dust particles (also known as metallic "needles" or "whiskers") are seen in carbonaceous chondrites and in samples brought back from the Itokawa asteroid. Their formation in protostellar nebulae and…

Astrophysics of Galaxies · Physics 2021-03-24 X. M. Huang , Qi Li , Aigen Li , J. H. Chen , F. Z. Liu , C. Y. Xiao

This review surveys the observed properties of interstellar dust grains: the wavelength-dependent extinction of starlight, including absorption features, from UV to IR; optical luminescence; IR emission; microwave emission; optical, UV, and…

Astrophysics · Physics 2008-11-26 B. T. Draine

Our current understanding of the absorption and emission properties of interstellar grains are reviewed. The constraints placed by the Kramers-Kronig relation on the wavelength-dependence and the maximum allowable quantity of the dust…

Astrophysics · Physics 2009-11-10 Aigen Li

Coagulation in the dense interstellar medium (ISM) is an important process that determines the size of the largest grains. We use submillimetre galaxies (SMGs) as laboratories of grain coagulation, since some of them host the densest ISM on…

Astrophysics of Galaxies · Physics 2023-10-09 Hiroyuki Hirashita , Chian-Chou Chen

The presence of ferromagnetic or ferrimagnetic nanoparticles in the interstellar medium would give rise to magnetic dipole radiation at microwave and submm frequencies. Such grains may account for the strong mm-wavelength emission observed…

Astrophysics of Galaxies · Physics 2015-06-05 B. T. Draine , Brandon Hensley

Processing by interstellar photons affects the composition of the icy mantles on interstellar grains. The rate of photodissociation in solids differs from that of molecules in the gas phase. The aim of this work was to determine an average,…

Astrophysics of Galaxies · Physics 2018-05-16 Juris Kalvans

The topological transitions that occur to the grain boundary network during grain growth in a material with uniform grain boundary energies are believed to be known. The same is not true for more realistic materials, since more general…

Materials Science · Physics 2021-10-29 Erdem Eren , Jeremy K. Mason