APNe Conference, Seattle, July 2003 Clumpy Flows in Protoplanetary and Planetary Nebulae Alexei...

APNe Conference, Seattle, July 2003APNe Conference, Seattle, July 2003

Clumpy Flows in Protoplanetary andPlanetary Nebulae

Alexei Poludnenko, Adam Frank

University of Rochester, Laboratory for Laser Energetics

Sorin Mitran

University of North Carolina

University of Rochester Laboratory for Laser Energetics

University of Rochester Laboratory for Laser Energetics


AstroBEAR Code and BEARCLAW packageBEARCLAW features: Unified code for computations in 1- 4 dimensions Automatic adaptive mesh refinement with flexible refinement parameters and scenarios Multi-physics capability Possibility of multiple subdomains of the computational domain with:

• different dimensionality, refinement scenarios, numerical schemes and/or Riemann solvers employed• different sets of PDEs solved on each one

A variety of output formats (AMRCLAW, TECPLOT, HDF, etc.)

AstroBEAR features: Computations in 2D, 2.5D, and 3D and access to all features without coding or recompilation Set of different Riemann solvers (full non-linear hydrodynamic, linearized Roe, linearized MHD) Generic implicit 4-th order accurate source term routine suited for arbitrary systems of source term ODEs Modular structure for user-supplied applications and a variety of provided initial conditions

Current AstroBEAR development: Full ionization dynamics and photoionization MHD Radiation driving via Sobolev approximation (e.g. radiatively driven disk outflows) MPI- and OpenMP- (SGI) based parallelization with full “knapsack-algorithm” load balancing Fast Multipole Method for elliptic equations Embedded boundaries for complicated flow geomtries

AstroBEAR results website: http://pas.rochester.edu/~wma


CRL 618 Susan R. Trammell (UNC Charlotte) et al.


Interacting regime of clump evolution: d = 0.95 dcrit

Non-interacting regime of clump evolution: d = 2.98 dcrit


Qualitative characteristics of adiabatic inhomogeneous systems:

thickness of the clump system as opposed to the total clump mass clump distribution in the system as opposed to the total number of clumps

Quantitative characteristics of the adiabatic clumpy systems: Critical density, critical separation between clump centers normal to the flow:

.11

)1(32)(2

2

1

2

1

10exp0

stc

SC

CCCDCCCDcrit

FF

t

ttattvad

Clump destruction length LCD, distance traveled by a clump prior to its breakup

Those two parameters allow one to distinguish between interacting andnoninteracting regimes of clump system evolution

Poludnenko, A.Y., Frank, A., Blackman, E.G. 2002, ApJ, 576, 832


Radiative Hypersonic Cosmic Bullets

An example of a radiatively cooled inhomogeneous environment

Systems are practically always in the noninteracting regime, i.e. there is no lateral expansion and merging

The main process is clump fragmentation via instabilities

The properties of the global flow determine the initial spectrum of fragments that are formed

The details of clump distribution determine the final spectrum of fragments

The final spectrum of fragments determines the structure and properties of the resulting system

Mach 20 radiatively cooled bullet, ambient density 102 cc-1, clump density 104, tcool/thydro = 2.8*10-3


Mach 10 radiatively cooled bullet, ambient density 103 cc-1, clump density 105, tcool/thydro = 2.5*10-2

Mach 10 radiatively cooled bullet, ambient density 102 cc-1, clump density 104 cc-1, tcool/thydro = 0.25


Mach 20 radiatively cooled bullet, ambient density 103 cc-1, clump density 105, t = 204 yrs. , tcool/thydro = 2.8*10-5


Mach 200 radiatively cooled bullet, ambient density 102 cc-1, clump density 104, t = 18.3 yrs. , tcool/thydro = 3.7

APNe Conference, Seattle, July 2003 Clumpy Flows in Protoplanetary and Planetary Nebulae Alexei...

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