Constraints on the Evolution of Massive Stars through Spectral Analysis. I. The WC5 Star HD 165763

摘要: Using a significantly revised non-LTE radiative transfer code that allows for the effects of line blanketing by He, C, O, Si, and Fe, we have performed detailed analysis Galactic Wolf-Rayet (W-R) star HD 165763 (WR 111, WC5). Standard W-R models consistently overestimate strength electron scattering wings, especially on strong lines, so considered where wind is both homogeneous clumped. The deduced stellar parameters are as follows: different from earlier analyses. luminosity factor 2 larger, smaller core radius found. in better agreement with expectations evolution calculations. Both these changes can be attributed to blanketing. C/He abundance similar calculations, O/He had not previously been determined. observed iron spectrum, principally due Fe V VI, well reproduced using solar mass fraction, although variation at least about this value cannot precluded. In particular, naturally produce emission feature centered 1470 A complex emission/absorption spectrum shorter wavelengths. Also, strongly modifies strengths profile shapes shortward 1800 must taken into account if successfully model region. reddening toward does follow mean extinction law. We determine law comparing our continuum levels observations. order simultaneously match UV, optical, particularly infrared fluxes, used parameterized Cardelli, Clayton, Mathis EB-V = 0.3 R 4.5, AV/EB-V. Based observational theoretical suggestions which still accelerating large radii. discuss velocity characterized β 1 r < 10R* but undergo substantial increase (~600 km s-1) beyond 10R*. These appear give slightly fits profiles, improvements small, it difficult gauge whether data require such yet winds stars driven radiation pressure, because neglect many higher ions, do include important elements cobalt nickel. However, problem less severe than assumed clumping occurs. For clumped model, single limit only exceeded 10 compared 3 times wind. Clumping appears key explaining apparent high mass-loss rates determined extremely understanding how or even pressure. reduction has implications