Clumps in supernova 1987A: the Hα line
We investigate the fine structure of the Hα emission line from SN 1987A in the period days 115–673. We find at least five bumps in the radial velocity range –2000 to + 1300 km s–1, with typical widths of 400–500 km s–1 and amplitudes 7–10 percent above the local emission level. These bumps start sho...
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Published in | Monthly notices of the Royal Astronomical Society Vol. 261; no. 4; pp. 909 - 920 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Oxford University Press
15.04.1993
Blackwell Science |
Subjects | |
Online Access | Get full text |
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Summary: | We investigate the fine structure of the Hα emission line from SN 1987A in the period days 115–673. We find at least five bumps in the radial velocity range –2000 to + 1300 km s–1, with typical widths of 400–500 km s–1 and amplitudes 7–10 percent above the local emission level. These bumps start showing up on day 115±5 and remain visible until day 523, at least one bump still being visible on day 673. Between days 115 and 523, the radial velocity of the bumps is approximately constant, with their amplitude gradually increasing. Between days 523 and 673, most bumps almost disappear, while one bump increases in relative strength. At that epoch, dust forms in the ejecta and changes the overall line profile considerably. Assuming that the bumps are due to local density enhancements (clumps) and that they suffer from dust extinction to a degree depending on their location in the ejecta, we show that the observed intensity contrast changes can be explained by selective dust extinction alone, if dust is distributed homogeneously in an inner shell of radius rd = 0.6 Rmax (where Rmax is the outer radius of the hydrogen shell) with dust optical depth $\tau = 3.5$, and if the clumps are concentrated in the inner part of the hydrogen shell at average radius 0.5 Rmax. |
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Bibliography: | istex:54FB88F64B0016F2DE4F2350E24E4F40F20A043C Based on observations obtained at the Anglo-Australian Telescope, Australia, and the 0.61-m Bochum telescope at the European Southern Observatory, La Silla/Chile ark:/67375/HXZ-C1FVR3GC-1 |
ISSN: | 0035-8711 1365-2966 |
DOI: | 10.1093/mnras/261.4.909 |