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We study the light scattering properties of random ballistic aggregates constructed in Shen et al. (Paper I). Using the discrete-dipole-approximation, we compute the scattering phase function and linear polarization for random aggregates…

Earth and Planetary Astrophysics · Physics 2011-02-11 Yue Shen , B. T. Draine , Eric T. Johnson

The backscattering of circularly polarized light at normal incidence to a half-space of scattering particles is studied using the Electric Field Monte Carlo (EMC) method. The spatial distribution of the backscattered light intensity is…

Optics · Physics 2009-11-11 Kevin G. Phillips , Min Xu , S. K. Gayen , R. R. Alfano

We extend the work of Mishchenko et al. (2000) regarding the exact results of the polarization effect, using the theory of Amic et al. (1997) to derive a model prediction for the polarization coherent opposition effect at small angles. Our…

Instrumentation and Methods for Astrophysics · Physics 2017-07-27 Adrian J. Brown

Many biologically produced chiral molecules such as amino acids and sugars show a preference for left or right handedness (homochirality). Light reflected by biological materials such as algae and leaves therefore exhibits a small amount of…

Photons preferentially Compton scatter perpendicular to the plane of polarisation. This property can be exploited to design instruments to measure the linear polarisation of hard X-rays ($\sim$10 - 100 keV). Photons may undergo two…

Instrumentation and Detectors · Physics 2023-01-25 Ettore Del Monte , Sergio Fabiani , Mark Pearce

Based on a sample of 355 quasars with significant optical polarization, we found that quasar polarization vectors are not randomly oriented over the sky as naturally expected. The probability that the observed distribution of polarization…

Astrophysics · Physics 2014-01-22 D. Hutsemekers , A. Payez , R. Cabanac , H. Lamy , D. Sluse , B. Borguet , J. -R. Cudell

Researchers routinely characterize optical samples by computing the scattering cross-section. However, the experimental determination of this magnitude requires the measurement and integration of the components of the scattered field in all…

In this work, we study the light scattering properties of dust aggregates ($0.7\mu m \lesssim R_c \lesssim 2.0\mu m$) having a wide range of porosity ($\mathcal{P}$ = 0.59 to 0.98). The simulations are executed using the Superposition…

Earth and Planetary Astrophysics · Physics 2018-05-16 Prithish Halder , Parizath Deb Roy , Himadri Sekhar Das

Polarization at millimeter wavelengths provides a powerful diagnostic of dust grain properties in protoplanetary disks. Standard models based on solid spherical grains often struggle to reproduce the observed polarization fractions and…

Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively levorotatory (L) amino acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The mechanism…

Astrophysics · Physics 2009-06-23 Marcelo Gleiser , Joel Thorarinson , Sara Imari Walker

Animal vision spans a great range of complexity, with systems evolving to detect variations in optical intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear…

Biological Physics · Physics 2011-12-06 Sonja Kleinlogel , Andrew G. White

We study the light scattering by localized quasi planar excitations of a Cholesteric Liquid Crystal known as spherulites. Due to the anisotropic optical properties of the medium and the peculiar shape of the excitations, we quantitatively…

Soft Condensed Matter · Physics 2018-10-24 G. De Matteis , D. Delle Side , L. Martina , V. Turco

The occurrence of biological homochirality is attributed to symmetry breaking mechanisms which are still debatable1. Studies of symmetry breaking require tools for monitoring the population ratios of individual chiral nano-objects, such as…

Optics · Physics 2018-08-20 Eitam Vinegrad , Uri Hananel , Gil Markovich , Ori Cheshnovsky

Linear scattering processes are usually described as a function of the parameters of the incident beam. The wavelength, the intensity distribution, the polarization or the phase are among them. Here, we discuss and experimentally…

Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 S. Trippe

Direct imaging has paved the way for atmospheric characterization of young and self-luminous gas giants. Scattering in a horizontally-inhomogeneous atmosphere causes the disk-integrated polarization of the thermal radiation to be linearly…

Earth and Planetary Astrophysics · Physics 2018-11-09 Tomas Stolker , Michiel Min , Daphne M. Stam , Paul Mollière , Carsten Dominik , Rens Waters

Photosynthesis is an ancient metabolic process that began on the early Earth, offering plentiful energy to organisms that utilize it, to the extent that they can achieve global significance. The potential exists for similar processes to…

The polarization of the light scattered by an optically dense, random solution of dielectric nanoparticles shows peculiar properties when the scatterers exhibit strong electric and magnetic polarizabilities. While the distribution of the…

Circular polarization of the cosmic microwave background (CMB) arises in the standard cosmological model from Faraday conversion of the linear polarization generated at the surface of last scatter by various sources of birefringence along…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-27 Marc Kamionkowski

It is generally assumed that magnetic fields play an important role in the formation and evolution of protoplanetary disks. One way of observationally constraining magnetic fields is to measure polarized emission and absorption produced by…

Solar and Stellar Astrophysics · Physics 2020-03-04 Stefan Heese , Sebastian Wolf