A Profile Analysis of Raman-scattered O VI Bands at 6825 Å and 7082 Å in Sanduleak's Star

Abstract

We present a detailed modeling of the two broad bands observed at 6825 Å and 7082 Å in Sanduleak's star, a controversial object in the Large Magellanic Cloud. These bands are known to originate from Raman-scattering of O VI $\lambda \lambda$ 1032 and 1038 photons with atomic hydrogen and are only observed in bona fide symbiotic stars. Our high-resolution spectrum obtained with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph at the Magellan-Clay Telescope reveals, quite surprisingly, that the profiles of the two bands look very different: while the Raman 6825 Å band shows a single broad profile with a redward extended bump, the Raman 7082 Å band exhibits a distinct triple-peak profile. Our model suggests that the O VI emission nebula can be decomposed into a red, blue and central emission regions from an accretion disk, a bipolar outflow and a further compact, optically thick region. We also perform Monte Carlo simulations with the aim of fitting the observed flux ratio $F(6825)/F(7082)\sim 4.5$, which indicate that the neutral region in Sanduleak's star is characterized by the column density $N_{HI}\sim 1\times 10^{23}\mathrm{c}{\mathrm{m}}^{-2}$.

11 pages, 5 figures, accepted for publication in ApJ

References in corpus (5)

• CalFUSE v3: A Data-Reduction Pipeline for the Far Ultraviolet Spectroscopic Explorer
• 3D simulations of RS Oph: from accretion to nova blast
• Numerical Simulations of Wind Accretion in Symbiotic Binaries
• Raman Scattered O VI $\lambda$ 6825 and the Accretion Disk Emission Model in the Symbiotic Stars V1016 Cygni and HM Sagittae
• Line formation regions of the UV spectrum of CI Cygni

Cited by in corpus (5)

• A census of symbiotic stars in the 2MASS, WISE and Gaia surveys
• RAMSES II - RAMan Search for Extragalactic Symbiotic Stars. Project concept, commissioning, and early results from the science verification phase
• Stellar Wind Accretion and Raman Scattered O VI Features in the Symbiotic Star AG Draconis
• Line Formation of Raman-Scattered He II $\lambda$ 4851 in an Expanding Spherical H I Shell in Young Planetary Nebulae
• Raman-scattered O VI features in the symbiotic nova RR Telescopii