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Infrared emission towards SN 1987A, 11 years after outburst: Properties of the circumstellar dust
- Source :
- Astronomy & Astrophysics. 395:189-200
- Publication Year :
- 2002
- Publisher :
- EDP Sciences, 2002.
-
Abstract
- Detailed models are presented for the late epoch mid infrared (MIR) emission from collisionally heated grains in the shocked circumstellar gas around SN 1987A. Thermal dust emission from a region of moderate density interior to the thick inner ring seen with the Hubble Space Telescope (HST) is found to be a natural explanation for the MIR spectral energy distribution measured by ISOCAM. The MIR-spectrum can be reproduced by a mixture of silicate-iron or silicate-graphite grains or by a composition of pure graphite grains. A composition of pure iron grains on the other hand can be excluded and a pure silicate composition does not seem to be very likely. The dust-to-gas ratio in the interaction zone is ~0.01%, an order of magnitude lower than estimates for dust abundances in the winds of red supergiant (RSG) stars in the LMC. This low dust abundance can be accounted for by a combination of evaporation through the UV-flash from the supernova outburst and subsequent sputtering in the shocked gas. For this explanation to hold, dust in the pre-supernova circumstellar medium (CSM) would have to have been predominantly composed of grains other than graphite, with a maximum size smaller than ~0.1 microns.
- Subjects :
- Physics
Infrared
Astrophysics::High Energy Astrophysical Phenomena
Evaporation
Astronomy and Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Silicate
chemistry.chemical_compound
Supernova
Stars
chemistry
Space and Planetary Science
Astrophysics::Solar and Stellar Astrophysics
Circumstellar dust
Spectral energy distribution
Red supergiant
Astrophysics::Earth and Planetary Astrophysics
Astrophysics::Galaxy Astrophysics
Subjects
Details
- ISSN :
- 14320746 and 00046361
- Volume :
- 395
- Database :
- OpenAIRE
- Journal :
- Astronomy & Astrophysics
- Accession number :
- edsair.doi...........8eac4f4ab9afd206707e73f70a0e6756