~Papers~

MHD shock paper

Check out outline on sharelatex

Paper ideas (for undergrad project)

Connie says there are no REU students, but that there may be undergrads available if Adam wants to hire them off of his grants?? I did a search and couldn't find any abstracts with the words Bonnor Ebert, radiation or radiative transfer. I think an easy project for a student would be running the collapse of a BE sphere with rad feedback. This could be a very high resolution run (AU scale, and could include MHD), where a disk forms. The questions might be:

• How does M-dot (and hence, accretion luminosity/rad feedback) change with rad feedback (relevant to the "luminosity problem" we were learning about last week)

• How does M-dot and rad feedback change when the BE sphere is embedded in 'realistic, continuous density medium'.

Paper ideas inspired by new Krumholz et al

Disentangling the effect of the outflows on support surrounding young protostars

Studying the role of turbulence and/or density fluctuations (last paragraph of conclusion says that is lacking)

Paper makes conclusions based on drawing spheres around sinks and calculating various critical masses — but can we test these ideas? under what limits do these ideas hold or not? Basically, trying to get a physical handle on the problem. Maybe this can also help with understanding why the accretion flow is not Bondi.

• 3-D pulsed jets are still running, only hydro run is finished. Beta = 1 run will be done in about a week on bluehive, beta = 5 is 75% done and beta = 0.4 is only 50% done on davinci. The queues on davinci take way too long, so I'm going to move the beta = 0.4 run to bluehive as well. It'll take a while since I can only get 120 cores, but at least it'll be making progress.

hydro emission movie​

• Ready to finish response to referee report on clumpy paper. Need to have meeting with Pat.

• Finished first draft of cooling paper, ready to revise and add figures. Working on some cooling curve plots now.

Mean Vorticity

Query results:

For S0:

Types of mean from query output:

Variable sum vorticity/NumZones = 68

Variable sum vorticity/Mass hockey puck = 21,537.9

Variable sum vorticity/ volume hockey puck = 107,120

Weighted sum vorticity/Numzones = .014

Weighted sum vorticity/Mass = 4.5

Weighted sum vorticity/Volume = 22.24

For S60:

Types of mean from query output:

Variable sum vorticity/NumZones = 17.19

Variable sum vorticity/Mass hockey puck = 2,373

Variable sum vorticity/ volume hockey puck = 4,748

Weighted sum vorticity/Numzones = .137

Weighted sum vorticity/Mass = 18.9

Weighted sum vorticity/Volume = 37.8458

Histos

"Density Weighted":

This plot is the one I sent around yesterday.

The issue may be that the y scaling is way off given the mass flux (and total masses) of the hockey pucks vary so much. To clarify, the masses of the various hockey pucks are (S0→S60):

So, I then defined a new variable that divides rho by the total mass of the puck for each of the runs. This is the "mass normalized rho", and then weighted the histos by these variables.

"Mass normalized rho weighted" (linear bin scale):

"Mass normalized rho weighted" (log bin scale):

Next, instead of weighting by a variable, did the histo by 'frequency':

So, in all of these cases, regardless of y-axis scaling, the max vorticity is highest in the lower shear cases… perplexing :-/

Min/Max Vorticity

Histo of vx

Instead of vorticity, how about spread in v? Or RMS v?

Here is vx histo for the diff runs:

Shock solutions

​https://astrobear.pas.rochester.edu/trac/wiki/u/erica/scratch3

Calculating the M2FR

Link: ​http://mnras.oxfordjournals.org/content/414/3/2511.full.pdf

So this is an execerise in thinking dimensionally and in order of magnitudes.

Consider the equation for radiation energy conservation ignoring a bunch of terms that should be of lower order

\frac{\partial E}{\partial t} \color{red}{ - \nabla \cdot \frac{c\lambda}{\kappa_{0R}} \nabla E}=\color{red}{\kappa_{0P} (4 \pi B-cE)}

The second term on the right hand side tells us about the diffusion of radiation and the right hand term tells us about coupling with matter.

Lets consider the diffusion term to get an estimate of the timescale,

We do this terms of dimensions (L = length, T= time etc). Radiation energy density E is, for example

[E ] = (\frac{ML^2}{T^2}) (\frac{1}{L^3}) = \frac{M}{T^2L}

So the diffusion term reads

[\nabla \cdot \frac{c}{\kappa_{R}} \nabla E ] = (\frac{1}{L}) (\frac{L}{T}) (\frac{L}{1}) (\frac{1}{L})(\frac{M}{T^2L}) = (\frac{1}{T}) (\frac{M}{T^2L})

which has units of energy of time as would be expected. To get a timescale for radiative diffusion t_{rd} we can write things in terms of the scales of the problem E_s and L_s

\frac{E}{\Delta t_{rd}} = \frac{c}{\kappa_R} E {L_s}^{-2}

or

\Delta t_{rd} = \frac{\kappa_R}{c} L_s^2

Note E_s drops out here

Now we just have to find values of the Rosseland opacity relevant to something like a dusty in falling protostellar envelope. I am seeing the Rosseland opacity being given in units of cm^{2/g which means we will need to multiply by a density scale in the above expression i.e.}

\kappa_R = \kappa_{Rv} *\rho_s

where \kappa_{Rv} is the value we get from tables and \rho_s is our density scale.

Here is a paper I found that gives some useful opacity information

​http://www.aanda.org/articles/aa/full/2003/41/aa3802/aa3802.right.html

Check out this table from the paper

• ​considering trajectories in lab frame
• Wire turbulence MHD run is at 157 and running well…
• Working on paper…

oneDstar.gif​

I intend to put this new wind model into our code. This movie shows only a radiative driven pulsating AGB wind. It has cooling.

I am going to apply it to the binary paper.

• Worked on cooling paper: abstract, intro, methods sections finished. Might've finished the whole thing had I not focused so much on recent referee report. I can release these sections for edits, and continue working on the rest.

• Worked on referee report for clumpy paper. I think most of it is resolved, and I don't think we have to change the paper too much. However, we still need to have a co-author discussion about gammas, cooling, and Mach stems. Below is a test simulation I ran to show that simulating a more "realistic" clump does not change our conclusions.

• 3-D jet simulations are still going. Here's a status update:

The beta=1 run will take significantly longer because it's on bluehive, but the other runs wait in the queue for so long in between restarts on davinci that all of these runs may finish around the same time in 3 weeks or so. Honestly don't see this project finishing in time to be part of my thesis, especially since we wanted to do additional runs with random pulses, less frequent pulses, no pulses, etc.

Papers

Referee Report Points:

The ref says, "Here, I list some points which should be added/clarified:"

Other points:

Data we are missing:

High Res Movies

Flow Texture

movie​

Old Versions

Read Murray-Clay paper: Authors seek to numerically determine validity of hypothesis that hot Jupiters could be evaporated down to their rocky cores over the planetary lifetime. They use a one-dimensional model that includes heating/cooling terms, tidal gravity, and the effects of ionization on the mass-loss rate, and ignore the Coriolis force. Numerically, they use a relaxation solver, and find solutions iteratively by removing simplifying conditions one at a time.

They find that, for main-sequence stars, about 20% of H is still neutral at the sonic point, and place an upper bound of ~3.3*10¹⁰ g/s on the mass loss rate. For hotter (T Tauri) stars, they find an upper bound of ~6.4*10¹² g/s. The assumption of a hydrodynamic wind is shown to be self-consistent, and they estimate that these are overestimates by ~4x. By reducing the wind speed to subsonic values and including a stellar wind, the day-side wind may be reduced or completely suppressed - they hypothesize that this may lead to night-side outflows.

They compare observations to estimates from their model, and note a few possible reasons for the disagreement in Lyman-alpha lines. A promising candidate is cited as acceleration of neutral hydrogen due to charge exchange. They note that modelled spectrally-unresolved measurements appear to be in agreement with observation.

movie​

Matsakos et al 2015 ​http://adsabs.harvard.edu/abs/2015A%26A...578A...6M

Tripathi 2016 ​http://adsabs.harvard.edu/abs/2015ApJ...808..173T

Frank et al 2015 ​http://adsabs.harvard.edu/abs/2015IAUS..314..237F

Stugaret 2015 ​http://adsabs.harvard.edu/abs/2015ApJ...815..111S

Christie ​http://adsabs.harvard.edu/abs/2016arXiv160105302C

Schnieter 2016 ​http://adsabs.harvard.edu/abs/2016MNRAS.457.1666S

Scnieter 2007 ​http://adsabs.harvard.edu/abs/2007ApJ...671L..57S

Bourrier 2013 ​http://adsabs.harvard.edu/abs/2013A%26A...557A.124B

Cohen 2009 ​http://adsabs.harvard.edu/abs/2009ApJ...704L..85C

Cohen 2010 ​http://adsabs.harvard.edu/abs/2011ApJ...733...67C