Astron. Astrophys. 337, 85-95 (1998)

Two-dimensional radiative transfer with transiently heated particles: methods and applications

V. Manske and Th. Henning

Astrophysical Institute & University Observatory Jena, Schillergäßchen 3, D-07745 Jena, Germany (manske@astro.uni-jena.de, henning@astro.uni-jena.de)

Received 22 December 1997 / Accepted 27 May 1998

Abstract

We present a combined treatment of two-dimensional (2D) continuum radiative transfer together with the emission of transiently heated small dust grains. To calculate this emission, an efficient and numerically stable algorithm was developed, which is outlined in detail. Using this new radiative transfer code, we were able to model the infrared emission of the starburst galaxy NGC 6090. We found that the assumed presence of transiently heated particles inside the dust torus of NGC 6090 is in agreement with the observed data. Special attention is given to the PAH emission lines, discovered in recent ISOPHOT-S observations of NGC 6090.

Our results show clearly that the emission of small particles influences significantly spectral energy distributions and intensity maps. Especially at wavelengths shorter than 10 µm, transiently heated particles are the main source of infrared radiation. Therefore, transiently heated particles seem to be highly relevant for understanding the nature of objects were these particles are present.

Key words: radiative transfer dust,extinction ISM: molecules galaxies: active galaxies: starburst infrared: galaxies

SIMBAD Objects

Contents

• 1. Introduction
• 2. Quantum heating
  • 2.1. Emission of small dust grains
    • 2.1.1. Transition matrix
    • 2.1.2. Adaptive temperature grid
  • 2.2. Heating of PAHs
• 3. The radiative transfer code
  • 3.1. Implementation of quantum heating
• 4. Application: the starburst galaxy NGC 6090
  • 4.1. Energy sources
  • 4.2. The dusty torus
    • 4.2.1. Dust models
    • 4.2.2. The model torus
  • 4.3. Results
    • 4.3.1. Effect of quantum heating
• 5. Conclusion
• References

© European Southern Observatory (ESO) 1998

Online publication: August 6, 1998
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