3D Radiative Transfer in Eta Carinae: Initial Results from the SimpleX Algorithm Applied to 3D SPH Simulations of Eta Car’s Massive Binary Colliding Winds
Abstract
An extremely luminous (>5 x 10^6 L_Sun) colliding wind binary with a highly eccentric (e ~ 0.9), 5.54-year orbit, total mass of at least 110 M_Sun, and distance of ~2.3 kpc, Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions, stellar wind-wind collisions, massive star evolution, and dust formation. Until very recently, our understanding of the system was limited by the lack of proper numerical models, which require a full three-dimensional (3D) treatment since orbital motion, especially during periastron, greatly affects the shape and dynamics of the wind-wind collision region formed between the stars. Continuing our theoretical investigations of this complex system, we present initial results from the application of the SimpleX algorithm for full 3D radiative transfer on an unstructured Delaunay grid to new 3D SPH simulations of Eta Car’s massive binary colliding winds that include radiation-driven stellar winds and radiative cooling. Depending on the ionizing fluxes assumed for the stars, different portions of the wind-wind interaction region and optically-thick wind of the LBV primary star are photoionized and capable of producing various forms of line emission. Application of the SimpleX algorithm to the 3D SPH code output further allows synthetic observations to be generated for comparison to available and future HST/STIS data. This work will be used to place strong constraints on the number of ionizing photons from the binary companion star Eta B since the geometry, spatial extent, and flux of each measured emission line strongly depends upon the assumed ionizing flux of the companion. By comparing this ionizing flux to stellar models for a range of O and WR stars, we hope to obtain a more accurate luminosity and temperature, and thus evolutionary state, for the as-yet unseen Eta B.
- Publication:
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American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22114816M