Physical Sciences and Mathematics Commons^™

Helium-Like X-Ray Line Complexes Show That The Hottest Plasma On The O Supergiant Ζ Puppis Is In Its Wind, David H. Cohen, Ariel M. Overdorff, M. A. Leutenegger, M. Gagné, V. Petit, A. David-Uraz

Physics & Astronomy Faculty Works

We present an analysis of Chandra grating spectra of key helium-like line complexes to put constraints on the location with respect to the photosphere of the hottest (T ≳ 6 × 10⁶ K) plasma in the wind of the O supergiant ζ Pup and to explore changes in the 18 yr between two sets of observations of this star. We fit two models—one empirical and one wind-shock-based—to the S XV, Si XIII, and Mg XI line complexes and show that an origin in the wind flow, above r ≈ 1.5 R∗, is strongly favoured over an origin less than 0.3 …