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Update Feb.19
TSF I set up a set of simulations with Boss cloud purturbed by an incoming wind:
- Pressure matched: no density jump, Mach = 1 (this is the case where the ram pressure from the wind equals the thermal pressure at the edge of the cloud)
- Density matched: the density of the wind matches that of the edge of the cloud, Mach = 1
- Boss condition: same as the density matched case but Mach = 10
- Magnetic Boss condition: same as the Boss condition but with a vertical magnetic field embedded in the domain (beta ~ 4)
Some of them should finish this week. I have also been going through some of the literature, the Gritschneder 2012 paper is interesting where they studied the triggered collapse of a marginally stable BE cloud with 10 solar masses and radius of 0.21, central mass about 104 with DM cooling. The shock velocity is considerably higher than that of Boss 2010: ranging in 100km/s to 200km/s, which is far out of the velocity window proposed by Boss 2010 for successful injection and collapse(20~70 km/s). This raises the question of how does this "successful window" depend on the cloud radius and mass question, which I have not seen a complete set of simulation/modeling done yet. They proposed the observed abundance of Al26 due to shock injection, which is similar to Boss' work.
http://arxiv.org/abs/1111.0012
The drawbacks are that these simulations are in 2D, no magnetic field or rotation, which they mentioned in the text:
" As this is an idealized case and the main focus of this study is the enrichment with SRLs, we don’t take any rotational or turbulent motion (e.g. Walch et al. 2010) inside the cloud core into account. While this initial rotation might be important in the later phases of the collapse - especially
in determining the final disk size - its influence will be very small in the initial phase here, as the rotational velocities are orders of magnitude smaller than the shock speeds."
"For example, the core could be initially rotating. We assume here that the high shock velocities dominate over the rotation, but this should be further investigated. Furthermore, we neglect magnetic fields. They are of course present and should be involved in various processes, e.g. the details of the shock front and especially later on in the disk formation and the removement of angular momentum."
It could be easy to set up simulations using their setting with weak rotation (beta = 0.01~0.1) and weak~medium field strength (beta = 4~100) in a 3D simulation. One challenge is to replicate their resolution in 3D, which is effectively 512 zones per cloud radii, need a effective resolution of 1200*1200*6000-ish (self gravity in reflect boundary condition?).
Also been going through some of the rotating/magnetic BE cloud papers:
http://arxiv.org/abs/0901.2127
http://arxiv.org/abs/astro-ph/0408277
http://adsabs.harvard.edu/abs/1993ApJ...417..220G
http://adsabs.harvard.edu/abs/1993ApJ...417..243G
Papers I have been writing up the draft for the MFU-IV proceeding.
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