Dust scattering simulation of far-ultraviolet light in the Milky Way

  • Jo, Young-Soo (Korea Astronomy and Space Science Institute (KASI)) ;
  • Seon, Kwang-Il (Korea Astronomy and Space Science Institute (KASI)) ;
  • Min, Kyoung-Wook (Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Jeong, Woong-Seob (Korea Astronomy and Space Science Institute (KASI)) ;
  • Witt, Adolf N. (University of Toledo)
  • Published : 2021.04.13

Abstract

We performed three-dimensional Monte Carlo dust scattering radiative transfer simulations for FUV light to obtain dust scattered FUV images and compared them with the observed FUV image obtained by FIMS/SPEAR and GALEX. From this, we find the scattering properties of interstellar dust in our Galaxy and suggest the intensity of extragalactic background light (EBL) at FUV wavelength. The best-fit values of the scattering properties of interstellar dust are albedo = 0.38-0.04+0.04, g-factor = 0.55-0.15+0.10, and EBL = 138-23+21 CU for the allsky which are consistent well with the Milky Way dust model of Draine and direct measurements of Gardner et al., respectively. At the high Galactic latitude of |b|>10°, the observation is well fitted with the model of lower albedo = 0.35-0.04+0.06 and g-factor = 0.50-0.20+0.15. On the contrary, the scattering properties of interstellar dust show higher albedo = 0.43-0.02+0.02 and g-factor = 0.65-0.15+0.05 near the Galactic plane of |b|<10°. In the present simulation, recent three-dimensional distribution maps of interstellar dust in our Galaxy, stellar distances in the catalog of GAIA DR2, and FUV fluxes and/or spectral types in the TD-1 and Hipparcos star catalogs were used.

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