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Петрова, Е. В.; Jockers, K.; Kiselev, N. N.

doi:10.1023/a:1012304321440

Cited by 15 publications

(13 citation statements)

References 16 publications

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“…Therefore, the negative polarization observed in comets at small α can only be explained by an aggregate structure of dust particles. An aggregate of random structure composed of monomers with size parameter close to 1.5 and refractive index close to (1.65 + i0.05) displays polarization properties (Petrova 2001b) similar to those observed in comets such as P/Halley, Hale-Bopp, and the present case of C/2000 WM1. These properties include negative polarization at small α, weak dependence of inversion angle α inv on wavelength, red colour of cometary dust and the degree of polarization independent of λ at low phase angles.…”

Section: On the Nature Of The Grainssupporting

confidence: 70%

“…Shkuratov and his colleagues showed that the negative branch of polarization appears if the particles of the scattering surface or their structural irregularities are comparable to the wavelength of radiation (Shkuratov 1994;Shkuratov et al 1994). Theoretical modeling of the properties of aggregate particles confirms that the collective effect of monomers significantly changes the single scattering characteristics of clusters as compared to those of the independent particles, and negative polarization can be produced with parameters (aggregate size, monomer size, wavelength, refractive index) close to those for the particles observed in cometary coma (West & Smith 1991;Xing & Hanner 1997;Petrova et al 2001b). …”

Section: On the Nature Of The Grainsmentioning

confidence: 94%

“…Therefore, the objects, which are quite different in nature (e.g. asteroids, planet Mercury, cometary coma) but show similar negative branch of polarization, supposedly have an aggregate structure of dust grains (Brownlee 1985a,b;West & Smith 1991;Petrova et al 2001a;Petrova et al 2001b). From the above facts one can infer that negative polarization of light at small phase angle is a collective effect of light scattering from particles and not a manifestation of their individual physical properties.…”

Section: On the Nature Of The Grainsmentioning

confidence: 99%

“…These properties include negative polarization at small α, weak dependence of inversion angle α inv on wavelength, red colour of cometary dust and the degree of polarization independent of λ at low phase angles. Petrova et al (2001b) have shown that a composite structure of aggregate particles resulting in the interaction of monomers in the light scattering process is responsible for the negative polarization at small phase angles if the monomer size is comparable to the wavelength of radiation. Comparison of the model calculations of Petrova et al (2001b) with the present observations indicates that the random structure composed of monomers of size parameter close to 1.5 and the refractive index close to (1.65 + i0.05) fits the observed polarization curve of WM1.…”

Section: On the Nature Of The Grainsmentioning

confidence: 99%

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Polarization studies of comet C/2000 WM1 (LINEAR)

Joshi

Baliyan

Ganesh

2003

A&A

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• ) when the polarization is negative and where the data for most of the comets are rather meager. The observations during March were made when the phase angle was ∼47• . Observations were conducted through the IHW narrow band and BVR broad band filters. Based on these polarization observations we infer that the comet C/2000 WM1 belongs to high polarization class i.e. the dusty comet family.

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Section: On the Nature Of The Grainssupporting

confidence: 70%

Section: On the Nature Of The Grainsmentioning

confidence: 94%

Section: On the Nature Of The Grainsmentioning

confidence: 99%

Section: On the Nature Of The Grainsmentioning

confidence: 99%

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Polarization studies of comet C/2000 WM1 (LINEAR)

Joshi

Baliyan

Ganesh

2003

A&A

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“…The electromagnetic interaction was not studied specifically for astronomical applications. However, the results presented by Chen et al (1988); Mishchenko et al (1995); Petrova et al (2000); Kimura & Mann (2004); Tishkovets et al (2004); Kolokolova et al (2006) demonstrate the influence of the electromagnetic interaction on the light scattering characteristics of aggregates, in particular, the depolarizing effect of the electromagnetic interaction. Both Mishchenko et al (1995) and Tishkovets et al (2004) showed that the polarization decreases as monomers in the aggregate become closer, and, thus, the interaction between them increases.…”

Section: Modeling the Electromagnetic Interaction Between Monomers Inmentioning

confidence: 91%

Effects of electromagnetic interaction in the polarization of light scattered by cometary and other types of cosmic dust

Kolokolova¹,

Kimura²

2010

A&A

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Context. We study how the electromagnetic interaction between the monomers in aggregates affects the polarization of cosmic dust. Aims. We aim to show that the electromagnetic interaction depends on the porosity and composition of the aggregates and contributes significantly to the spectral gradient of polarization (polarimetric color). The results may explain the observations of some comets that demonstrated atypical negative polarimetric color in the visible and also a reverse of the positive polarimetric color to the negative one in the near-infrared. Methods. We performed computer simulations of the light scattering by aggregates consisting of spheres made of a variety of materials: transparent, absorptive, and the material similar to that of the dust in comet Halley. We studied how the number of monomers covered by the electromagnetic wave at a single period (on the light path equal to one wavelength) affects their interaction by considering linear clusters of 2 and 10 monomers of radius of 0.1 μm. Results. Electromagnetic interaction between the monomers in aggregates depolarizes the light. The interaction becomes stronger if more monomers are covered by the electromagnetic wave at a single period. Thus, the porosity of aggregates influences their polarization. The electromagnetic interaction also depends on composition and is stronger for transparent materials. Conclusions. Electromagnetic interaction between the monomers in aggregates may explain why the polarimetric color of comet dust decreases as observations move from the visible to the near-infrared since a longer wavelength covers more monomers. It may also explain why some comets exhibit negative polarimetric color even in the visible; these comets may have more compact dust. Strong electromagnetic interaction resulted either from compactness or transparency of the material can explain the negative polarimetric color of interplanetary dust and debris disks and contribute to the polarization of asteroids. In general, the spectral dependence of polarization is a promising tool for studying the properties of cosmic dust particles, particularly their porosity.

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Light Scattering and Thermal Emission by Primitive Dust Particles in Planetary Systems

Kimura

Kolokolova

et al. 2016

Light Scattering Reviews, Volume 11

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Untitled

Cited by 15 publications

References 16 publications

Polarization studies of comet C/2000 WM1 (LINEAR)

Polarization studies of comet C/2000 WM1 (LINEAR)

Effects of electromagnetic interaction in the polarization of light scattered by cometary and other types of cosmic dust

Light Scattering and Thermal Emission by Primitive Dust Particles in Planetary Systems

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