• ANKUR GOGOI

      Articles written in Journal of Astrophysics and Astronomy

    • Scattering by interstellar graphite and fayalite composite dust analogues: computer simulation and laser-based laboratory measurements

      MANASH J. BORUAH ANKUR GOGOI GAZI A. AHMED

      More Details Abstract Fulltext PDF

      Scattering properties of irregularly shaped interstellar composite dust analogues consisting of graphite and fayalite (Fe$_2$SiO$_4$) were studied using discrete dipole approximation (DDA). Two dust models were developed to calculate the scattering and extinction efficiencies, single scattering albedo, asymmetry parameter, phase functions and degree of linear polarizations. Laboratory measurements were also performed at three incident wavelengths 543.5, 594.5 and 632.8 nm on chemically synthesized graphite and fayalitecomposite particles of sizes ranging from 0.3 to 5 $\mu$m. A comparative analysis of the theoretical and experimental results of shape- and size-averaged scattering parameters shows that changes in the percentage composition of a two-species mixture model has a pronounced effect on the light-scattering properties of dust particles. The developed computational models are successful in representing a two-species mixture of interstellar dust analogues considering diverse size, shapes and percentage composition. This technique canbe applied to fit observed scattering and absorption peaks in the visible region produced by astrophysical dust, provided large number of particle species are included and the influence of more physical parameters (e.g., porosity, fluffiness, temperature, density, etc.) are considered. Further, this study is also applicable to remote sensing, atmospheric and planetary sciences. All the physical parameters employed as variables in the models influence the oscillations observed in theoretical curves and change the values of scatteringparameters.

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.