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Mass ejection from the O4f star Zeta Puppis

1976; Institute of Physics; Volume: 32; Linguagem: Inglês

10.1086/190413

1538-4365

H. J. G. L. M. Lamers, D. C. Morton,

Solar and Space Plasma Dynamics

view Abstract Citations (239) References (85) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Mass ejection from the O4f star Zeta Puppis. Lamers, H. J. G. L. M. ; Morton, D. C. Abstract Profiles of P Cygni lines and displaced absorption lines observed in high-resolution Copernicus UV scans of Zeta Pup from 907 to 1738 A are compared with profile calculations to derive an optical-depth scale of the lines as a function of height or velocity in the expanding envelope. The degrees of ionization of the elements C, N, O, Si, and S under equilibrium conditions at electron temperatures of 20,000 to 1 million K, radiation temperatures of 20,000 to 50,000 K, and electron number densities of 100 million to 1 trillion per cu cm are computed with a dilution factor of 0.1, taking into account collisional ionization by electrons, radiative ionization from the ground state, radiative recombination, and dielectric recombination. Observed and predicted relative ionization fractions are then compared to determine the electron and radiation temperatures. Crude and refined estimates of the mass-loss rate and velocity law are made, and radiative acceleration in the expanding envelope is analyzed. The derived model for Zeta Pup is found to have a mass-loss rate of about 7.2 millionths of a solar mass per year, a wind velocity that increases slowly outward and reaches 700 km/s about 28 solar masses, and a nearly isothermal envelope with an electron temperature of approximately 200,000 K. Publication: The Astrophysical Journal Supplement Series Pub Date: October 1976 DOI: 10.1086/190413 Bibcode: 1976ApJS...32..715L Keywords: Absorption Spectra; O Stars; Stellar Mass Ejection; Stellar Models; Acceleration (Physics); Electron Scattering; Far Ultraviolet Radiation; Ionization; Mass Flow Rate; Stellar Envelopes; Stellar Winds; Velocity Distribution; Astrophysics full text sources ADS | data products SIMBAD (10)