Evidence for the importance of resonance scattering in X-ray emission line profiles of the O star $\zeta$ Puppis

Abstract

We fit the Doppler profiles of the He-like triplet complexes of \ion{O}{7} and \ion{N}{6} in the X-ray spectrum of the O star $\zeta$ Puppis, using XMM-Newton RGS data collected over $\sim 400$ ks of exposure. We find that they cannot be well fit if the resonance and intercombination lines are constrained to have the same profile shape. However, a significantly better fit is achieved with a model incorporating the effects of resonance scattering, which causes the resonance line to become more symmetric than the intercombination line for a given characteristic continuum optical depth ${\tau }_{\ast }$. We discuss the plausibility of this hypothesis, as well as its significance for our understanding of Doppler profiles of X-ray emission lines in O stars.

arXiv comment29 pages, 8 figures, revised version accepted by ApJ

References in corpus (20)

• A Grid of NLTE Line-Blanketed Model Atmospheres of O-type Stars
• The surprising magnetic topology of tauSco: fossil remnant or dynamo output?
• The Discordance of Mass-Loss Estimates for Galactic O-Type Stars
• Low mass loss rates in O-type stars: Spectral signatures of dense clumps in the wind of two Galactic O4 stars
• Line ratios for Helium-like ions: Applications to collision-dominated plasmas
• Chandra HETGS Multi-Phase Spectroscopy of the Young Magnetic O Star theta^1 Orionis C
• High resolution X-Ray spectroscopy of Zeta Puppis with the XMM-Newton Reflection Grating Spectrometer
• The Effect of Porosity on X-ray Emission Line Profiles from Hot-Star Winds
• Chandra Discovers a Very High Density X-ray Plasma on the O-Star Zeta Orionis
• High resolution X-ray spectroscopy of bright O type stars
• Detection of Doppler Shifted X-ray Line Profiles from the Wind of Zeta Puppis (O4f)
• X-ray line emission from a fragmented stellar wind
• X-Ray Line Profiles from Parameterized Emission Within an Accelerating Stellar Wind
• Constraints on the Ionization Balance of Hot-Star Winds from FUSE Observations of O Stars in the Large Magellanic Cloud
• High-Resolution {\it Chandra} Spectroscopy of tau Scorpii: A Narrow-Line X-ray Spectrum From a Hot Star
• X-ray Emission Line Profile Modeling of O stars: Fitting a Spherically-Symmetric Analytic Wind-Shock Model to the Chandra Spectrum of zeta Puppis
• Measurements and analysis of helium-like triplet ratios in the X-ray spectra of O-type stars
• X-ray emission lines from inhomogeneous stellar winds
• Wind signatures in the X-ray emission line profiles of the late O supergiant $\zeta$ Orionis
• High Resolution X-ray Spectra of the Brightest OB Stars in the Cygnus OB2 Association

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