Dynamical origin of wind structure
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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

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Dynamical origin of wind structure

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

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

Spatial Porosity

• Same amount of material

• More light gets through

• Less interaction between

matter and light

Incident light


Effective opacity

porosity length=h

Effective opacity


Porous envelopes

l=0.05r

l=0.1r

l=0.2r

Porous envelopes

h=0.5r

hºl/f

h=r

h=2r


Profile weighted line column depth

Step function

Profile-weighted line column depth


Line absorption trough

b=1

t¥=1/4

1/2

1

2

Line absorption trough


Velocity vs mass

Velocity vs. Mass


Velocity vs mass1

Velocity vs. Mass

}

DV

Velocity

filling factor :

dv

}


Velocity vs mass2

Velocity vs. Mass


Velocity porosity

Vorosity?

“Velocity Porosity”


Absorption reduction

Absorption reduction

f = 1

RA

0.5

0.2

0.1

tx


Line absorption

smooth, b=1

porous, fv = 1-v/2v¥

t=1/4

t=1/4

1/2

1

2

1

2

Line absorption


Dynamical origin of wind structure

Line-Driven Instabilty sim (SSF)


Instability model

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 depth1

Profile-weighted line column depth

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Profile weighted line column depth2

Profile-weighted line column depth

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum weak line

Dynamic absorption spectrum-weak line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum weak line1

Dynamic absorption spectrum-weak line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum med line

Dynamic absorption spectrum - med. line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum med line1

Dynamic absorption spectrum - med. line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum strong line

Dynamic absorption spectrum-strong line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum strong line1

Dynamic absorption spectrum-strong line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Time averaged absorption profiles

Weak

Medium

Strong

Time-Averaged Absorption Profiles

1

I /Icont

0

-1

0

Wavelength (V¥)


Time averaged absorption profiles1

Weak

Medium

Strong

Time-Averaged Absorption Profiles

1

I /Icont

0

-1

0

Wavelength (V¥)


Dynamic absorption spectra

Weak

Medium

Strong

Dynamic absorption spectra

0

-1

0

0

-1

-1

Wavelength (V¥)

0

-1

0


Summary

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


2d simulation of co rotating interaction regions

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 depth3

Profile-weighted line column depth

8

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dynamic absorption spectrum med line2

Dynamic absorption spectrum-med. line

8

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dyn abs spectrum very strong line

Dyn. abs. spectrum - very strong line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Dyn abs spectrum very strong line1

Dyn. abs. spectrum - very strong line

4

Time

(days)

0

CAK init. cond.

-1

0

Wavelength (V¥)


Instability model mdot

Instability model: Mdot

4

Time

(days)

0

CAK init. cond.

1

radius (R*)

10


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