Accretion onto the Companion of Eta Carinae During the Spectroscopic Event. V. the Infrared Decline
arXiv:0709.0090 · doi:10.1016/j.newast.2008.03.003
Abstract
We propose that the decline in the near-IR flux from the massive binary system Eta Carinae during the spectroscopic event might be explained by accreted mass that absorbs the radiation from the secondary star, and by that reduces the heating of the dust that is responsible for the near-IR emission. This binary system has an orbital period of 2024 days and eccentricity of e~0.9. The emission in several bands declines for several weeks near every periastron passages, in what is termed the spectroscopic event. In the accretion model for the spectroscopic event the secondary star accretes mass from the primary's wind for ~10 weeks near every periastron passage. The mass is accreted mainly in the equatorial plane. The disk and its wind block the secondary's radiation from heating dust that does not reside within narrow cones along the symmetry axis. This, we propose, might explain the decline in the near-IR flux occurring at the beginning of each spectroscopic event. We also argue that the increase in the near-IR prior to the event might be accounted for by enhanced hot (T~1700 K) dust formation in the collision region of the winds from the two stars. This dust resides within ~60 degrees from the equatorial plane, and most of it cannot be heated by the secondary during the accretion phase.
Accepted for publication by New Astronomy
References in corpus (7)
- The Structure of the Homunculus. II. Modeling the physical conditions in Eta Car's molecular shell
- Accretion onto the Companion of Eta Carinae During the Spectroscopic Event: III. the He II 4686 Line
- The Source of the Helium Visible Lines in Eta Carinae
- Modelling the Radio Light Curve of Eta Carinae
- A high-velocity transient outflow in Eta Carinae
- Submillimetre Emission from Eta Carinae
- Dust from AGB stars
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- Possible Implications of Mass Accretion in Eta Carinae
- The Orientation of the Eta Carinae Binary System
- Explaining the Early Exit of Eta Carinae from its 2009 X-Ray Minimum with the Accretion Model
- Prediction for the He I 10830A Absorption Wing in the Coming Event of Eta Carinae
- The X-ray properties of Eta Carinae during its 2020 X-ray minimum
- Accretion in the Binary System GG Carinae and Implications for B[e] Supergiants