1. Marco Miceli, INAF – Osservatorio Astronomico di Palermo Consorzio COMETA, Italy Collaborators F. Bocchino, INAF – Osservatorio Astronomico di Palermo, Italy F. Reale, INAF – OAPa, Università di Palermo, Italy S. Orlando, INAF – Osservatorio Astronomico di Palermo, Italy 5 th Jetset School on High Performance Computing in Astrophysics 8 th -13 th January 2008 Galway, Ireland Hydrodynamic evolution of ejecta in the Vela SNR

2. Supernova Remnants Supernova explosion  Total energy released:  10 53 erg  “Visible” energy:  10 51 erg  Mass ejected: several solar masses G292.0+1.8  Formation of blast wave shocks  Heating of the ambient medium  Compression  Interaction with interstellar clouds  Propagation of the ejecta  Chemical enrichment of the galaxy  Propagation of supersonic “bullets”

3. The Vela SNR Distance: ~250 pc Age: ~11000 yr In middle-aged SNR the bulk of the X-ray emission is commonly associated with shocked ISM, but: Vela SNR: 6 X-ray emitting “shrapnels”, that are probably associated with ejecta (outside the border of the shell). Recent discovery of new shrapnels inside the shell (Miceli et al. 2007, ApJ accepted) 0.1-2.3 keV Rosat All Sky Survey

4. Hydrodynamic modeling  : mass density v : bulk velocity P : pressure E : tot. energy per unit mass q :  (T)  T (Spitzer & saturated) n : density  ( T ): radiative losses function  : internal energy per unit mass Numerical solution through the FLASH HD code (Fryxell, 2000) P= Aims: evolution of supersonic fragments of ejecta (interaction with the shock waves and with the ambient medium) Equations of the model:

5. Hydrodynamic modeling r (cm) z (cm) Initial conditions: exploding sphere of ejecta with a density inhomogeneity (i. e. the shrapnel)  M ej = 12 M ⊙  E = 10 51 erg  R 0 = 4.5 x 10 18 cm  V ej (R 0 ) = 6 x 10 18 cm/s (v(R)  r)   (R) following Wang & Chevalier 2002  M shrapnel = 1/20 M ej   shrapnel =   ej 2-D simulations in cylindrical coordinates (axial symmetry). We follow the evolution of the system for ~ 15000 yr (the Vela age is ~ 11000 yr)

6. Parameter space exploration (*) : We investigate how the evolution of the system depends on the density contrast (between the shrapnel and the surrounding ejecta) and on the initial position of the shrapnel. R shrapnel /R 0  “Complete” run executed on the CINECA CLX cluster (total CPU time~9000 h) “Complete” runs to be done on the COMETA HPC system Pure HD run (no thermal cond. no rad. losses) executed on the HPC system COMETA (total CPU time~250 h, memory~7 Mb, output size~3 Gb). Hydrodynamic modeling (*) Work in progress…

7. log  (g/cm 3 ) T (K) spatial res. 2048 x 2048 point The Vela SNR 0.1-2.4 keV ROSAT All SKy Survey (0.1-2.4 keV) The “pure HD” run:  = 30, R shr = 1/3 R 0 ) Hydrodynamic modeling