New project with Enrico and Jamie at UCSC.
ASASSN-14ko is a Periodic Nuclear Transient in ESO 253−G003
The orbital period is about 100 days. The idea will that this star was in an eccentric bound orbit, had a stellar interaction that slightly altered its orbit and redirected towards the black hole.
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Toy models for a TDE event (parabolic initial orbit)
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FLASH & MESA documents from Jamie
https://github.com/jamielaw-smith/STARS-sims-doc are the main instructions
https://github.com/jamielaw-smith/multitidal is the FLASH setup source code
https://github.com/jamielaw-smith/jYT and https://github.com/jamielaw-smith/realistic-structure are analysis code.
https://github.com/jamielaw-smith/FLASH-mentoring-instructions is a catch-all, copy and paste of misc instructions
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Sink particles (Federrath et al. 2010)
If the gas has reached a given density, a sink particle is introduced, which can accrete the gas exceeding the threshold, without al- tering the thermal physics.
For a collapsing system, the free-fall timescale
$t_\text{ff}$ decreases with increasing density $$ t_\text{ff}=\sqrt{\frac{3\pi}{32G\rho}} $$ Following the free-fall collapse/accretion, the change in density could cover over ten orders of magnitude. Such high dynamical range is beyond the modern numerical schemes and supercomputers. InFLASH, theSinkParticleunit can identify the dense yet gravitationally bound gas and turn it into sink particles.Once created, sink particles are free to move within the Cartesian computational domain, independent of the underlying grid, i.e., they move in the Lagrangian frame of reference, while the grid points are fixed in space (Eulerian frame of reference). The outer boundary conditions, i.e., outflow, reflecting, or periodic also apply to the sink particles in the simulation box.