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Related papers: Interstellar extinction by fractal polycrystalline…

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Certain dust particles in space are expected to appear as clusters of individual grains. The morphology of these clusters could be fractal or compact. In this paper we study the light scattering by compact and fractal polycrystalline…

Astrophysics · Physics 2009-11-07 A. C. Andersen , J. A. Sotelo , V. N. Pustovit , G. A. Niklasson

Dust particles in space may appear as clusters of individual grains. The morphology of these clusters could be of a fractal or more compact nature. To investigate how the cluster morphology influences the calculated extinction of different…

Astrophysics · Physics 2007-05-23 A. C. Andersen , J. A. Sotelo , G. A. Niklasson , V. N. Pustovit

A composite dust grain model which simultaneously explains the observed interstellar extinction, polarization, IR emission and the abundance constraints, is required. We present a composite grain model, which is made up of a host silicate…

Solar and Stellar Astrophysics · Physics 2013-10-02 Nisha Katyal , Ranjan Gupta , D. B. Vaidya

Observations of interstellar extinction and polarization indicate that the interstellar medium consists of aligned non-spherical dust grains which show variation in the interstellar extinction curve for wavelengths ranging from NIR to UV.…

Astrophysics · Physics 2009-09-15 Ranjan Gupta , Tadashi Mukai , D. B. Vaidya , Asoke K. Sen , Yasuhiko Okada

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

The review contains an analysis of the observed and model curves of the interstellar extinction and polarization. The observations mainly give information on dust in diffuse and translucent interstellar clouds. The features of various dust…

Astrophysics of Galaxies · Physics 2015-06-05 N. V. Voshchinnikov

How dust scatters and absorbs starlight in the interstellar medium (ISM) contains important clues about the size and composition of interstellar dust. While the ultraviolet (UV) and visible interstellar extinction is well studied and can be…

Astrophysics of Galaxies · Physics 2015-06-19 Shu Wang , Aigen Li , B. W. Jiang

We model the ~1--19$\mum$ infrared (IR) extinction curve toward the Galactic Center (GC) in terms of the standard silicate-graphite interstellar dust model. The grains are taken to have a power law size distribution with an exponential…

Astrophysics of Galaxies · Physics 2015-06-16 Jian Gao , Aigen Li , B. W. Jiang

It is generally agreed that interstellar dust grains consist of two main components, namely, silicates and graphites. Some models, like MRN model, assume these grains to be homogeneous spheres following a power law size distribution. This…

Astrophysics of Galaxies · Physics 2009-03-30 Ashim K. Roy , Subodh K. Sharma , Ranjan Gupta

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

We construct a quasar extinction curve based on the blue and red composite quasar spectra of Richards et al. (2003) prepared from the SDSS survey. This extinction curve does not show any traces of the 2200 A feature characteristic of the…

Astrophysics · Physics 2009-11-10 B. Czerny , J. Li , Z. Loska , R. Szczerba

We interpret the interstellar extinction observed towards the Galactic Center (GC) in the wavelength range $\lambda = 1 - 20\,\mkm$. Its main feature is the flat extinction at $3 - 8\,\mkm$ whose explanation is still a problem for the…

Astrophysics of Galaxies · Physics 2017-03-08 Nikolai V. Voshchinnikov , Thomas Henning , Vladimir B. Il'in

We extend and investigate the spheroidal model of interstellar dust grains used to simultaneously interpret the observed interstellar extinction and polarization curves. We compare our model with similar models recently suggested by other…

Astrophysics of Galaxies · Physics 2015-05-14 H. K. Das , N. V. Voshchinnikov , V. B. Il'in

Particle shape and aggregation have a strong influence on the spectral profiles of infrared phonon bands of solid dust grains. In this paper, we use a discrete dipole approximation, a cluster-of-spheres code following the Gerardy-Ausloos…

Astrophysics · Physics 2007-05-23 Anja C. Andersen , Harald Mutschke , Thomas Posch

The sizes of interstellar grains are widely distributed, ranging from a few angstroms to a few micrometers. The ultraviolet (UV) and optical extinction constrains the dust in the size range of a couple hundredth micrometers to several…

Astrophysics of Galaxies · Physics 2015-09-23 Shu Wang , Aigen Li , B. W. Jiang

This review describes our current understanding of interstellar extinction. This differ substantially from the ideas of the 20th century. With infrared surveys of hundreds of millions of stars over the entire sky, such as 2MASS,…

Astrophysics of Galaxies · Physics 2017-06-13 George Gontcharov

Dust in galaxies can be mapped by either the FIR/sub-mm emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction measurements for a set of fifteen sections in…

DENIS observations in the J (1.2 micron) and K_S (2.15 micron) bands together with isochrones calculated for the RGB and AGB phase are used to draw an extinction map of the inner Galactic Bulge. The uncertainty in this method is mainly…

The Two Micron All Sky Survey, along with the Stellar Population Synthesis Model of the Galaxy, developed in Besancon, is used to calculate the extinction distribution along different lines of sight. By combining many lines of sight, the…

Astrophysics · Physics 2011-04-08 D. J. Marshall , A. C. Robin , C. Reyle , M. Schultheis , S. Picaud

Interstellar dust is a major foreground contaminant for many observations and a key component in the chemistry of the interstellar medium, yet its properties remain highly uncertain. Using low-resolution spectra, we accurately measure the…

Astrophysics of Galaxies · Physics 2024-07-23 Xiangyu Zhang , Gregory Green
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