A numerical radiative transfer model based on the Monte Carlo principle is used to explain the observed surface brightness distribution of the nearby barred spiral galaxy NCG 253 in the optical and FIR domains. The modeled data consists of new ISOPHOT observations at 120 and 180 micron as well as IRAS fluxes and optical photometry. The model reveals an optically thick, extended dust disk with a central face-on optical thickness τV = 5+/-1. Total dust mass of the dominating dust population, the large grains in thermal equilibrium, is 2.8 x 107 Msun and the FIR luminosity of the large grain population is 1.0 x 1010 Lsun. The radial scale length of the dust population is somewhat larger than the corresponding value of the stellar disk.
Proceedings 232. WE-Heraeus Seminar
- Pub Date:
- December 2000