Marco Miceli, INAF – Osservatorio Astronomico di PalermoConsorzio COMETA, Italy

Collaborators

F. Bocchino, INAF – Osservatorio Astronomico di Palermo, Italy F. Reale, INAF – OAPa, Università di Palermo, ItalyS. Orlando, INAF – Osservatorio Astronomico di Palermo, Italy

5th Jetset School onHigh Performance Computing

in Astrophysics

8th-13th January 2008 Galway, Ireland

Hydrodynamic evolution of Hydrodynamic evolution of ejecta in the Vela SNRejecta in the Vela SNR

Supernova RemnantsSupernova Remnants

Supernova explosion

Total energy released: 1053 erg

“Visible” energy: 1051 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”

The Vela SNRThe Vela SNR

The Vela SNRDistance: ~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

Hydrodynamic modelingHydrodynamic modeling

: mass densityv: bulk velocityP: pressureE: tot. energy per unit massq: (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 modelingHydrodynamic modeling

r (cm)z

(cm

)

Initial conditions: exploding sphere of ejecta with a density inhomogeneity(i. e. the shrapnel)

Mej = 12 M⊙

E = 1051 erg

R0 = 4.5 x 1018 cm

Vej(R0) = 6 x 1018 cm/s (v(R) r)

(R) following Wang & Chevalier 2002

Mshrapnel = 1/20 Mej

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)

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.

Rsh

rap

nel/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 modelingHydrodynamic modeling

(*) Work in progress…

log (g/cm3) T (K)spatial res. 2048 x 2048 point

The Vela SNR0.1-2.4 keV

ROSAT All SKy Survey(0.1-2.4 keV)

The “pure HD” run: = 30, Rshr = 1/3 R0)

Hydrodynamic modelingHydrodynamic modeling