English

Ionizing Photon Emission Rates from O- and Early B-type Stars and Clusters

Astrophysics 2009-11-10 v1

Abstract

We present new computations of the ionizing spectral energy distributions (SEDs) and Lyman continuum (Lyc) and HeI continuum photon emission rates, for hot O-type and early B-type stars. We consider solar metallicity stars, with effective temperatures ranging from 25,000 to 55,000 K and surface gravities (cm s^-2) logg ranging from 3 to 4, covering the full range of spectral types and luminosity classes for hot stars. We use our updated (WM-basic) code to construct radiation-driven wind atmosphere models for hot stars. Our models include the coupled effects of hydrodynamics and non-LTE radiative transfer in spherically outflowing winds, including the detailed effects of metal line blocking and line blanketing on the radiative transfer and energy balance. We incorporate our hot-star models into our population synthesis code (STARS), and we compute the time-dependent SEDs and resulting Lyc and HeI emission rates for evolving star clusters. We present results for continuous and impulsive star formation for a range of assumed stellar initial mass functions.

Keywords

Cite

@article{arxiv.astro-ph/0312232,
  title  = {Ionizing Photon Emission Rates from O- and Early B-type Stars and Clusters},
  author = {Amiel Sternberg and Tadziu Hoffman and Adalbert Pauldrach},
  journal= {arXiv preprint arXiv:astro-ph/0312232},
  year   = {2009}
}

Comments

23 pages, 7 figures. To appear in the Astrophysical Journal. For grid of star models see ftp://wise3.tau.ac.il/pub/stars