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Co-rotating binaries disk formation, PAPER FIGURES

To do list form the meeting on June 21.

Confirm we have a disk in the 20au case by comparing the disk's radial velocity profile vs a keplerian one.

State in the paper that we are not far (far) from the WRLOF limit in the 10au (20au) cases, and refer to
- Mohamed-Podsiadlowski, http://adsabs.harvard.edu/abs/2011ASPC..445..355M)
- Sandin, http://adsabs.harvard.edu/abs/2008MNRAS.385..215S

Assess the numerical viscosity in our sims by comparing current 10 and 20 au sims with different effective resolutions

10AU case. Not significant difference once steady.

Analyze the accretion that we find with
- profiles of radial mass flux on a longitudinal plane, vs polar angle and time
- 2d maps of radial mass flux on the orbital plane vs time
- compare profiles of Mdot vs time for 10au sims with
  - orbital motion (exiting data)
  - no orbital motion (new quick run)

Runs
- keep running current 20au
- start running a 15 au
- start running a 30 au

IN NO PARTICULAR ORDER

1. 10au accretion rate evo. Still higher than expected. val-borro et al. table3, report $\dot{M}_{acc}/\dot{M}_{wind} \sim$0.06 after 2 orbits for a 70AU case. The {\bf gradients} in the corresponding accretion rate evo profile (their fig. 12) are similar to ours; a very fast and brief initial increase followed by rather mild variations.
2. 20au accretion rate evo.
3. 10au Disk mass evo.
4. 20au Disk mass evo.
5. 10 au, disk density structure at 4 times, orbital plane view. The disk is consistently asymmetric. By time=.1 orb it has a width of about 1.5 AU. By time=1orb, the disk radius increases 4-fold and its morphology changes mildly. Density gradients are steeper in the disk part that faces the incoming wind.
6. 10 au, disk density structure at 4 times, longitudinal plane view. The disk has a flared structure.
7. 20 au, disk density structure at 4 times, orbital plane view.
8. 20 au, disk density structure at 4 times, longitudinal plane view.
9. 10 au (black) vs. 20 au (red), disk orbit streamlines comparison at 3 times: 1orb=thin; 2orb=thicker; 3orb=thickest, orbital plane view. Grid squares are 1 AU².

Posted: 12 years ago (Updated: 12 years ago)
Author: martinhe
Categories: (none)

Comments

1. Jonathan -- 12 years ago

With the mass flux I think there are two questions we would like to answer…

Does most of the accreted mass come in from the poles or from the disk?
Is the mass flux through the disk fairly uniform as a function of phi - or is there a strong anisotropy in mass flux due to the 'backflow'…

To answer the first question, you could make a plot of phi-integrated radial mass flux (rho v_r) vs. polar angle theta within a shell at some distance r (8 cells) that is a greater than the particles accretion radius (4 cells)… though that could be tricky do to in practice… Perhaps it would be easier to make a movie of a rotating longitudinal slice of a pseudocolor plot of radial mass flux…

The second question could be answered by a plot of theta-integrated radial mass flux vs. phi within the same shell… Or just a slice through the orbital midplane of a pseudocolor plot of radial mass flux…

2. martinhe -- 12 years ago

Here's a quick example of an idea to show the distribution of the gas flux towards the particle for the 10au case, after 1 orbit.

The image shows the projection of the linear momentum vector onto the radial vector. Maps are logarithmic. Left panel is the orbital plane. Right panel is the xz plane, as indicated by the red line. White regions show gas moving away from the particle. The equatorial radial mass flux has a spiral shape and is ~70 times higher than the polar one.

3. Jonathan -- 12 years ago

So if the wind is always effectively pushed away from the primary, there will be this differential acceleration between the disk and the secondary. The disk feels an additional outward radiation pressure throughout the disk. It's probably impossible to have a stable orbit when there is a net acceleration… Probably could calculate inward spiral pitch angle as a function of distance… Perhaps this is also responsible for the high accretion rates? In reality there would might be self-shielding within the disk which would allow the inner disk to exist in a more keplerian type orbit?

4. martinhe -- 12 years ago

Jonathan: Is the distance you refer to in calculate inward spiral pitch angle as a function of distance… the stats' separation or the radial distance from the secondary?

I agree… there's an acceleration gradient within the disk, and this should exert stress on it.

5. martinhe -- 12 years ago

ovies of (3d) radial inward mass flux density, $\vec{p} \cdot -\hat{r} = -(x\,p_x+y p_y+z\,p_z)/|r|$, where $\vec{p}$ is the linear momentum vector. The red material accretes while blue one goes away from the particle. Polar accretion does not dominate the toroidal+radial one

Note that the color scale on the right is smaller than that on the left to stress gradients.

6. martinhe -- 12 years ago

3d view of the above radial inward mass flux density for the 10AU case http://www.pas.rochester.edu/~martinhe/2012/binary/10radFlux3d.gif

7. martinhe -- 12 years ago

20 AU, gas trajectory lines: http://www.pas.rochester.edu/~martinhe/2012/binary/20lines.gif

8. martinhe -- 12 years ago

10 AU, gas trajectory lines http://www.pas.rochester.edu/~martinhe/2012/binary/10lines.gif