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Fermi Project Update 02/18/21
Goal: Figure out how to make the probe velocity and range normally distributed within our FORTRAN model.
Method: First added a local variable called 'technology' to the program.
Then used random walks to have it be normally distributed around the technological capabilities of the abiogenesis seed (first habited system). Finally, I made the probe range and velocity relativistic functions of this new technology variable. The table below shows the initial values inputted into the model.
| Inputs | ||
|---|---|---|
| v0 | 0.0001c=30 km/s | Initial Probe Velocity |
| r0 | 10 lyr | Initial Probe Range |
| t0=r0/v0 | 100,000 years | Initial Probe Lifetime |
Click here to see the PDF which summarizes calculation/implementation of the normally distributed probe ranges/distances
Click here for more information about the input variables for the models shown below.
Notes
- The pink boxes surround systems that are uninhabited.
- All simulations begin with 10 systems originally habited.
- Galaxy Model shows time with unit Myr. Total runtime being 1000 Myr.
- In contrast, the periodic box model has a total runtime of 1 Myr. Thus I show frames instead of time, where each frame is approximately 1/1000 Myr.
- x=(number of habited systems)/(total number of systems)
Galaxy Model
Periodic Box Model
Analytic Model
Update 02/15
Notes about the Federrath+14 jet/outflow model:
http://www.pas.rochester.edu/~yzou5/CE/notes_Federrath+14_jet_model.pdf
Jet parameters in our model:
| Jet Data | ||
| jet_radius | 16 | size of outflow region in finest level cells |
| jet_collimation | .2618 | pi/12 !collimation of outflow |
| jet_temp | 30000. | jet temp in Kelvin |
| jet_index | 1. | exponent of collimation |
| jet_masslossrate | 2e0 | solar masses / yr |
| lcorrect | T | Apply conservative correction |
| jet_vrad | 430.75 | km/s radial velocity of jet, use Keplerian velocity for m2 and 1 solar radius |
| jet_vphi | .5 | km/s approximate rotation speed of jet |
| spin_axis | 0d0,0d0,1d0 | outflow axis |
to-do's
- understand the feedback module. what are the initial profiles of density and velocity inside the spherical cones launching the jets?
- compute how much of the jet material is unbound, using the spline potential, velocity profile and density profile.
- plot the jet tracer density
Updates 2/15/21
Early Asteroid Magnetization
Adding lineouts of the day side to illustrate the issues of theoretical estimates of amplification.
Moon Impact Magnetization
Settled on a spherical field distribution of the form:
Will add another blog post about the equations and plot for current, and magnetic potential.
Hot Neptunes
I have forgotten how to compile code it seems. Should be an easy fix.
Fermi Project Update (02/13/2021)
Goal: Figure out how to make the probe velocity and range normally distributed within our FORTRAN model.
Method: First added a local variable called 'technology' to the program.
Then used random walks to have it be normally distributed around the technological capabilities of the abiogenesis seed (first habited system). Finally, I made the probe range and velocity relativistic functions of this new technology variable. See the pdf below for more details about calculation/implementation.
Click here to see the PDF which summarizes my progress so far and potential steps.
Current Model Output (Colored by Technology, Pink=Unsettled)
| Inputs | ||
|---|---|---|
| v0 | 0.0001c=30 km/s | Initial Probe Velocity |
| r0 | 10 lyr | Initial Probe Range |
| t0=r0/v0 | 100,000 years | Initial Probe Lifetime |
Figure: The above gif shows the temporal evolution of a model galaxy. Beginning with 10 habited solar systems (ie: abiogensis seeds), these systems send probes out to nearby systems, thus making those systems inhabited and repeating the process until the entire galaxy is filled with life. The uninhabited systems are shown as the pink boxes. Note that a selection effect results in the systems on the outer edge of the galaxy gaining high technological abilities before systems near the center.
Initial Conditions for Lunar Impact Magnetization
Based on the impactor conditions from Oran et al. (2020) https://advances.sciencemag.org/content/6/40/eabb1475 and its supplementary material https://advances.sciencemag.org/content/suppl/2020/09/28/6.40.eabb1475.DC1/abb1475_SM.pdf we have most impact plasma conditions apart from the magnetic field (which they do not seem to inject by any mechanism).
Impact Plasma conditions from iSALE-2D :
- Initial Vapour temperature: 2000 K (varies down to 500 K for some models)
- Wind Speed: 400 km/s to 1000 km/s
- Wind Density: Plots in S4, but no analytical form. Looks proportional to y.
- Magnetic field: Probably several equations work.
Assuming the field distribution is similar to that of a very thick (radius ), finite length (), current carrying wire, the field and vector potential in cylindrical coordinates are:
- Resistivity Profile: Same as used for the NSF proposal.
We can start
