Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-05-05
Astronomy and Astrophysics
Astrophysics
19 pages, 6 figures, accepted by A&A
Scientific paper
We present simulations of Far Infrared (FIR) emission by dust in spiral galaxies, based on the Monte Carlo radiative transfer code of Bianchi, Ferrara & Giovanardi (1996). The radiative transfer is carried out at several wavelength in the Ultraviolet, optical and Near Infrared, to cover the range of the stellar Spectral Energy Distribution (SED). Together with the images of the galactic model, a map of the energy absorbed by dust is produced. Using Galactic dust properties, the spatial distribution of dust temperature is derived under the assumption of thermal equilibrium. A correction is applied for non-equilibrium emission in the Mid Infrared. Images of dust emission can then be produced at any wavelength in the FIR. We show the application of the model to the spiral galaxy NGC 6946. The observed stellar SED is used as input and models are produced for different star-dust geometries. It is found that only optically thick dust disks can reproduce the observed amount of FIR radiation. However, it is not possible to reproduce the large FIR scalelength suggested by recent observation of spirals at 200 um, even when the scalelength of the dust disk is larger than that for stars. Optically thin models have ratios of optical/FIR scalelengths closer to the 200um observations, but with smaller absolute scalelengths than optically thick cases. The modelled temperature distributions are compatible with observations of the Galaxy and other spirals. We finally discuss the approximations of the model and the impact of a clumpy stellar and dust structure on the FIR simulations.
Alton Paul B.
Bianchi Simone
Davies Jonathan I.
No associations
LandOfFree
Monte Carlo Predictions of Far-Infrared Emission from Spiral Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Monte Carlo Predictions of Far-Infrared Emission from Spiral Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Monte Carlo Predictions of Far-Infrared Emission from Spiral Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-440664