Mass loss from inhomogeneous hot star winds II. Constraints from a combined optical/UV study

Details Mass loss from inhomogeneous hot star winds II. Constraints from a combined optical/UV study Mass loss from inhomogeneous hot star winds II. Constraints from a combined optical/UV study

2011-01-27

arxiv.org/abs/1101.5293v2

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

14 pages+1 Appendix, 8 figures, 3 tables. Accepted for publication in Astronomy and Astrophysics. One reference updated, minor

Scientific paper

Mass-loss rates currently in use for hot, massive stars have recently been seriously questioned, mainly because of the effects of wind clumping. We investigate the impact of clumping on diagnostic ultraviolet resonance and optical recombination lines. Optically thick clumps, a non-void interclump medium, and a non-monotonic velocity field are all accounted for in a single model. We used 2D and 3D stochastic and radiation-hydrodynamic (RH) wind models, constructed by assembling 1D snapshots in radially independent slices. To compute synthetic spectra, we developed and used detailed radiative transfer codes for both recombination lines (solving the "formal integral") and resonance lines (using a Monte-Carlo approach). In addition, we propose an analytic method to model these lines in clumpy winds, which does not rely on optically thin clumping. Results: Synthetic spectra calculated directly from current RH wind models of the line-driven instability are unable to in parallel reproduce strategic optical and ultraviolet lines for the Galactic O-supergiant LCep. Using our stochastic wind models, we obtain consistent fits essentially by increasing the clumping in the inner wind. A mass-loss rate is derived that is approximately two times lower than predicted by the line-driven wind theory, but much higher than the corresponding rate derived from spectra when assuming optically thin clumps. Our analytic formulation for line formation is used to demonstrate the potential impact of optically thick clumping in weak-winded stars and to confirm recent results that resonance doublets may be used as tracers of wind structure and optically thick clumping. (Abridged)

Affiliated with

Also associated with

No associations

Rating

Mass loss from inhomogeneous hot star winds II. Constraints from a combined optical/UV study does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Mass loss from inhomogeneous hot star winds II. Constraints from a combined optical/UV study, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mass loss from inhomogeneous hot star winds II. Constraints from a combined optical/UV study will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-545493