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

Supernova Remnants Supernova explosion  Total energy released:  erg  “Visible” energy:  erg  Mass ejected: several solar masses G  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”

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) keV Rosat All Sky Survey

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:

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 = erg  R 0 = 4.5 x cm  V ej (R 0 ) = 6 x 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 ~ yr (the Vela age is ~ yr)

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…

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