Distribution of dust and stars in the Galaxy
  Using far-infrared 240 micron and near-infrared K band data from the COBE/DIRBE instrument, we model the Galactic stellar and dust distribution. Making the assumption that the Galaxy is transparent in the 240 micron band, the dust emission is modeled using the following components: a warped exponential disk of scale length 0.26 R_sun, a spiral arm component as mapped by HII regions, and a feature coinciding with the local (Orion) arm. The dust distribution is used to calculate absorption in the K band, and the stellar emission is likewise modeled with a warped exponential disk, with a scale length of 0.29 R_sun, and a spiral arm component. Models of the K band emission in the Galactic plane indicate that in this waveband a two arm spiral dominates the nonaxisymmetric emission. The warp is evident in both the dust and stellar component, and is found to start within the Solar Circle. 
Ronald Drimmel and David Spergel