국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Constraining the Absolute Orientation of eta Carinae''s Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission
저자	Madura, T. I.;; Gull, T. R.;; Owocki, S. P.;; Groh, J. H.;; Okazaki, A. T.;; Russell, C. M. P.
Keyword	COMPANION STARS;; HUBBLE SPACE TELESCOPE;; HYDRODYNAMICS;; LINE OF SIGHT;; NEBULAE;; RADIATIVE TRANSFER;; SIMULATION;; SPACEBORNE TELESCOPES;; SPECTROGRAPHS;; STELLAR MASS;; TEMPORAL DISTRIBUTION;; THREE DIMENSIONAL MODELS
URL	http://hdl.handle.net/2060/20110023549
보고서번호	GSFC.JA.5510.2011
발행년도	2011
출처	NTRS (NASA Technical Report Server)
ABSTRACT	We present a three-dimensional Ɠ-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car''s binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer''s side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.