On the velocity structure in clumpy planetary nebulae Café de grano o soluble: Micro-estructuras en nebulosas planetarias Wolfgang Steffen Alberto López Instituto de Astronomía UNAM, Ensenada MyPN 5

Observations: Velocities of clumps up to > 500 km/s Linear velocity gradients for clumps and jets at large distances from the CS High speed tails up to ~ 200 km/s Theory: Magnetic “jets” (García-Segura 1999) & Stagnation knots (Steffen, W. 2001) show linear v-gradients This paper: Quasi-spherical clump distribution from instabilities and clumpy AGB-remnant overrun by fast post AGB-wind NGC 2440

Abell 30 Borkowski et al Chu et al (X-Ray) Borkowski et al. 1995

Images and velocities of fast head-tail structures Abell 78 Meaburn et al. 1998

Images and velocities of very fast symmetric FLIERs MyCn18, O’Connor, Meaburn et al.

García-Segura et al. 1999

Steffen, W., et al Stagnation knots

Steffen & López in prep. Fast stellar wind in 1 / r^2 environment (AGB-wind) Dynamical instabilities conv. shocks Thermal instabilities shock before cooling

Clumps due to dynamical and thermal instabilities Distance [units 1e15 cm] Velocity [cm/s]

Steffen & López, in prep. Fast stellar wind and pre-existing clumps log number density

density distribution Shock acceleration of clouds Speed of cloud after shock wind ambient medium

Steffen & López, in prep. Simplified equation of motion Continuous wind acceleration of clouds Terminal velocity not equal local wind velocity v c = F ( v i,  r, v co, r o ) Clump velocity v c_inf = G ( v i,  v co, r o ) For large times evolution becomes self-similar.

Velocity vs. distance evolution for 2 different clump densities Low density High density

Velocity vs. distance for different densities of clouds for fixed time self-similar (low density) not self-similar (high density)

Velocity vs. distance scatter plot pre-existing clouds distance [cells] Velocity 200 km/s 1000 km/s high density low density colour is log density

Velocity vs. distance scatter plot pre-existing clouds distance [cells] Velocity [cm/s] model low density tails (not modeled) colour is log density

Velocity vs. Density scatter plot log density [1/ccm] Velocity 200 km/s 1000 km/s pre-existing clouds instability clouds

Velocity spikes from tails of dense clumps Distance [units 1e15 cm] Velocity [cm/s]

MyPN 3 Conclusions: Velocity stratification with density Initial shocked clump velocity ~ 1/r Linear velocity gradient for large r Multi-valued velocities at small r and high densities Velocity structure from instability clumps & pre-existing clumps is very different More velocity and density diagnostics needed

MyPN 5

Preexisting clumps and due to thermal instabilities Distance [units 1e15 cm] Velocity [cm/s]