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Project Pages (Stuff currently on my plate - ordered by priority)

• Scrambler Paper
• Gravitationally induced turbulence
• Colliding Flows
• Thermally Unstable clouds
• MHD Clumps
• Mapping Out Cooling Regimes for Shocked Clumps
• The Morphological Impact of Cooling on Turbulence

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• test  -- Posted on 3 years ago : author Jonathan
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• Thoughts on time stepping and MHD  -- Posted on 4 years ago : author Jonathan

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Journal Club for March 22

Literature survey:

Klessen Heitsch MacLow 2000

• Collapse can only be prevented with unrealistically short wavelength driving
• Realistic driving ength gives observed core formation rates
• Discuss various dispersion relations for jeans analysis with turbulence
• Reference Bonazzola 1992 which has a critical spectra for support of alpha = 3 (outflow turb?)
• SPH and Lagrangian 3D Hydro Periodic 64 Jeans Masses
• Drive with various scales for 1 crossing time and then switch on self-gravity
• Forcing patterns described in MacLow 1998 and 1999

Heitsch Maclow Klessen 2000

• Similar to above but with MHD
• Density contrasts are lessened because of magnetic pressure
• Flow is organized into sheets - more clustered

Ossenkiof Klessen Heitsch

• Applied delta variance technique to self gravitating turbulence
• Periodic Box
• Density spectra has positive slope when self-gravity is important
• Propose to compare it with dust observations instead of 12CO to have a higher density contrast range
• 256³

Heitsch et al 2005

• Non-gravitating hydro colliding flows with cooling
• NTSI, KH, TI, but no discussion of Richtmeyer-Meshkov instability (Impulsive-accelerating RT instability)
• Look at 'core' properties (though 2D and no SG)

Heitsch et al 2006 "Birth of Molecular Clouds"

• Extended 2005 work to 3D
• no sg and hydro
• sinusoidal interface
• .5 particles/cc
• periodic (open in 2D)

Audit & Hennebelle 2005

• 2D colliding flows

Heitsch et al 2006 "Magnetized Non-Linear thin shell instability -2D"

• 2D MHD using PROTEUS
• Fields weaken or suppress NTSI

Heitsch et al 2006 "Cloud Dispersal in Turbulent Flows"

• no sg- looked at turbulent dispersal of clouds

Heitsch, Stone, and Hartmann 2008 "Effects of Magnetic Field Strencth and Orientation on Molecular Cloud Formation"

• Athena 3D 256³ - no sg - mhd
• Fields are important to resulting structure
• Fields normal to flow favor filamentary structure in collision plane
• Fields perpendicular to flow (ie y ) suppress ntsi along field axis (ky /= 0) and give an extended slab with filaments normal to field

Heitsch, Hartmann, and Burkert "Fragmentation of Shocked Flows: Gravity, Turbulence, and Cooling"

• Theory paper
• Star formation happens soon after MC formation
• Density enhancements are produced along with MC - problem with 'condensation models'
• Nead non-linear density enhancements - faster than gravity
• Discuss TI, GI, NTSI, KHI
• Phase diagrams with lines outlining dominate instabilities
• Dynamical and thermal instabilities dominate on small scales
• Thermal fragmentatation dominates gravitational fragmentation during cloud formation
• TI alone cannot produce jeans unstable clumps… need additional global compression

VazqueszSemadeni 2006

• Velocity perturbations

Inoue and Inutsuka 2012

• Colliding Flows in 3D
• Richtmyer-Meshkov instability
• No dynamical sg
• 1024³

Radiation

Mixed frame

E_r F_r P_r are in lab frame - source terms in fluid frame

need closure relation Variable Eddington Tensor Stiff source terms (modified gudonov method) Wide range of timescales (implicit differencing)

Short characteristics Solve transfer equation across domain using time independent Stellar atmosphere code

Beam test Shadow test

Modified Gudonov method

source terms included in reconstruction step semi-implicit picard iteration scheme ensures stability

Fully implicit backward euler differencing - sparse matrix (no sub-cycling)

​http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012ApJS..199...14J&db_key=AST&link_type=ABSTRACT ​http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012ApJS..199....9D&db_key=AST&link_type=ABSTRACT