Abstract Details
| Name: Akshaya Subbanna M S Affiliation: Christ University Conference ID: ASI2016_440 Title : Modelling of the dust scattered halos observed around bright stars Authors and Co-Authors : Akshaya Subbanna M S, Christ University, Bengaluru Ravichandran. S, Christ University, Bengaluru Jayant Murthy, Indian Institute of Astrophysics, Bengaluru Abstract Type : Poster Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : Interstellar dust plays a major role in the formation of stars and the evolution of a galaxy. However, various properties of interstellar dust grains are poorly understood. The optical properties of the interstellar dust grains are mainly described using two parameters - the albedo (a) and the phase function asymmetry factor (g). We have derived these properties using the halo observed around bright stars, which is due to the scattering of starlight by dust located between us and the star. A thorough analysis of such halos around bright stars can yield useful information regarding the properties and distribution of dust grains in our Galaxy. We selected four stars which were known to have UV halos and modelled the UV emission around them. The brightness and the extent of the observed halos depend on a number of parameters such as, the intrinsic luminosity of the star, optical properties of the grains, the distance between the star and the dust, the density of dust grains in the scattering layer and scattering cross section of the grains. UV data from the Galaxy Evolution Explorer (GALEX) and IR data from Infrared Astronomical Satellite (IRAS) and Planck were used for the halo modelling. We present here the derived optical properties and the distribution of the dust grains obtained from the modelling of the four stars. |