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Dynamical Origin of Wind Structure. Stan Owocki Bartol Research Institute Department of Physics & Astronomy University of Delaware. The effect of “velocity porosity” on P-Cygni line absorption strength. Key Issues. What is effect of wind clumping on line-absorption?
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Dynamical Origin of Wind Structure Stan Owocki Bartol Research Institute Department of Physics & Astronomy University of Delaware The effect of “velocity porosity” on P-Cygni line absorption strength
Key Issues • What is effect of wind clumping on line-absorption? • Velocity dispersion vs. Spatial Porosity • What are relevant scaling parameters (cf. fr, h=l/f)? • In dynamical model, how important for, eg. PV?
Spatial Porosity • Same amount of material • More light gets through • Less interaction between matter and light Incident light
porosity length=h Effective opacity
l=0.05r l=0.1r l=0.2r Porous envelopes h=0.5r hºl/f h=r h=2r
Step function Profile-weighted line column depth
b=1 t¥=1/4 1/2 1 2 Line absorption trough
Velocity vs. Mass } DV Velocity filling factor : dv }
Vorosity? “Velocity Porosity”
Absorption reduction f = 1 RA 0.5 0.2 0.1 tx
smooth, b=1 porous, fv = 1-v/2v¥ t=1/4 t=1/4 1/2 1 2 1 2 Line absorption
4 4 Time (days) 0 1 10 radius (R*) 0 1 10 radius (R*) Velocity Instability model Density CAK init. cond.
Profile-weighted line column depth 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Profile-weighted line column depth 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum-weak line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum-weak line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum - med. line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum - med. line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum-strong line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum-strong line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Weak Medium Strong Time-Averaged Absorption Profiles 1 I /Icont 0 -1 0 Wavelength (V¥)
Weak Medium Strong Time-Averaged Absorption Profiles 1 I /Icont 0 -1 0 Wavelength (V¥)
Weak Medium Strong Dynamic absorption spectra 0 -1 0 0 -1 -1 Wavelength (V¥) 0 -1 0
Summary • Spatial porosity for continuum opacity • characterized by “porosity length” h=l/fr • But for line opacity, key is“velocity clumping” • characterized by fvel(and tSob of smoothed wind) • Line-driven instability suggests: • fvel ~= 0.7-0.8 (maybe 0.5 if seeded by low freq. pert) • Mdot misunderestimated by fvel , i.e. 0.5-0.8 • Maybe upto a factor 2 of the ca. 10 needed for PV
nonlocal structured model 2D Simulation of Co-rotating Interaction Regions D log(Density) c. a. b. nonlocal local smooth CAK model model
Profile-weighted line column depth 8 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dynamic absorption spectrum-med. line 8 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dyn. abs. spectrum - very strong line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Dyn. abs. spectrum - very strong line 4 Time (days) 0 CAK init. cond. -1 0 Wavelength (V¥)
Instability model: Mdot 4 Time (days) 0 CAK init. cond. 1 radius (R*) 10