Blog
About

33
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      X-Ray Absorption and Scattering by Interstellar Grains

      Preprint

      ,

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Interstellar abundance determinations from fits to X-ray absorption edges often rely on the incorrect assumption that scattering is insignificant and can be ignored. We show instead that scattering contributes significantly to the attenuation of X-rays for realistic dust grain size distributions and substantially modifies the spectrum near absorption edges of elements present in grains. The dust attenuation modules used in major X-ray spectral fitting programs do not take this into account. We show that the consequences of neglecting scattering on the determination of interstellar elemental abundances are modest; however, scattering (along with uncertainties in the grain size distribution) must be taken into account when near-edge extinction fine structure is used to infer dust mineralogy. We advertise the benefits and accuracy of anomalous diffraction theory for both X-ray halo analysis and near edge absorption studies. An open source Fortran suite, General Geometry Anomalous Diffraction Theory (GGADT), is presented that calculates X-ray absorption, scattering, and differential scattering cross sections for grains of arbitrary geometry and composition.

          Related collections

          Author and article information

          Journal
          2015-09-29
          2016-02-04
          Article
          10.3847/0004-637X/817/2/139
          1509.08987

          http://arxiv.org/licenses/nonexclusive-distrib/1.0/

          Custom metadata
          ApJ 817 139 2016
          32 pages, 15 figures
          astro-ph.HE astro-ph.GA astro-ph.IM astro-ph.SR

          Comments

          Comment on this article