A model for the radio flare from SN 1987A
| Autor: | M. Wassmann, J. G. Kirk |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Physics
Astrophysics::High Energy Astrophysical Phenomena Stellar rotation Astronomy Synchrotron radiation Cosmic ray Astrophysics Shock (mechanics) law.invention Supernova law Physics::Space Physics Reflection (physics) Astrophysics::Solar and Stellar Astrophysics Adiabatic process Astrophysics::Galaxy Astrophysics Flare |
| Zdroj: | AIP Conference Proceedings. |
| ISSN: | 0094-243X |
| Popis: | We present an acceleration mechanism based on multiple reflection of electrons by a shock front and apply it to explain the radio flare observed from SN1987A two days after explosion. The radiation mechanism is assumed to be synchrotron radiation from accelerated electrons which pass through the supernova shock front after having bounced off it many times during its early expansion into the progenitor’s stellar wind. Multiple reflection occurs because the wind contains a magnetic field wound into the form of a spiral by stellar rotation: the spiral becomes evermore tightly wound as the shock progresses outward and reflected electrons are unable to escape radially.For parameters appropriate to SN1987A, the shock becomes superluminal and reflections cease after a time of the order of days. The subsequent decay of the flare is a result of adiabatic losses in the expanding downstream plasma. The predicted spectrum is a power law I∝ν−1 above the synchrotron self‐absorption frequency, consistent with observations. |
| Databáze: | OpenAIRE |
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